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					             Application to the Research Council of Norway
                             Environment and Development
                                             The Climate and Ozone Committee




Coordinated Ozone and UV project
                                  Phase 2
                Revised project proposal for 2001-2002 by:
                              Geir O. Braathen
                  Norwegian Institute for Air Research, Kjeller
                          With contributions from:
 Bill Arlander, NILU-Kjeller; Bojan Bojkov, NILU-Kjeller; Arne Dahlback, UiO;
Kåre Edvardsen, NILU-Tromsø; Inga Fløisand, NILU-Kjeller; Michael Gauss, UiO,
Georg Hansen, NILU-Tromsø; Ulf-Peter Hoppe, FFI; Britt Ann Kåstad Høiskar, NI-
LU; Ivar Isaksen, UiO; Berit Kjeldstad, NTNU; Arve Kylling, NILU-Kjeller; Yvan
Orsolini, NILU-Kjeller; Bjørg Rognerud, UiO; Frode Stordal, NILU-Kjeller; Jostein
        Sundet, UiO; Trond Morten Thorseth, NTNU; Eivind Thrane, FFI;

                      Date of preparation: 30 January 2001


      March 1980                                          March 1997
                                 Total ozone
                                  Dobson Units
                                       Above 420
                                         405 - 420
                                         390 - 405
                                         375 - 390
                                         360 - 375
                                         345 - 360
                                         330 - 345
                                         315 - 330
                                         300 - 315
                                       Below 300
             Application to the Research Council of Norway
                             Environment and Development
                                           The Climate and Ozone Committee




Coordinated Ozone and UV project
                                  Phase 2
                Revised project proposal for 2001-2002 by:
                              Geir O. Braathen
                  Norwegian Institute for Air Research, Kjeller
                          With contributions from:
 Bill Arlander, NILU-Kjeller; Bojan Bojkov, NILU-Kjeller; Arne Dahlback, UiO;
Kåre Edvardsen, NILU-Tromsø; Inga Fløisand, NILU-Kjeller; Michael Gauss, UiO,
Georg Hansen, NILU-Tromsø; Ulf-Peter Hoppe, FFI; Britt Ann Kåstad Høiskar, NI-
LU; Ivar Isaksen, UiO; Berit Kjeldstad, NTNU; Arve Kylling, NILU-Kjeller; Yvan
Orsolini, NILU-Kjeller; Bjørg Rognerud, UiO; Frode Stordal, NILU-Kjeller; Jostein
        Sundet, UiO; Trond Morten Thorseth, NTNU; Eivind Thrane, FFI;

                      Date of preparation: 30 January 2001
                                               Contents
CHAPTER 1:                  Executive Summary                                . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7

  1.1 How does COZUV-2 constitute a continuation of COZUV-1? . . . . . . . . . . . . . . . . . . . . .7
  1.2 What do we apply for? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7
  1.3 The project participants . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
  1.4 What is the problem? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .8
  1.5 What are the scientific objectives of this proposal? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
  1.6 What methods will be used? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .9
  1.7 Time schedule . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
  1.8 How will the results be disseminated? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10
  1.9 Policy issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10


CHAPTER 2:                  Introduction                  . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .10


CHAPTER 3:                  The applicants’ knowledge of the field                                                      . . . . . . . . . . . . .11

  3.1 Geir O. Braathen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
  3.2 Bill Arlander . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .11
  3.3 Bojan Bojkov . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
  3.4 Inga Fløisand . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
  3.5 Georg Hansen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
  3.6 Britt Ann Kåstad Høiskar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
  3.7 Arve Kylling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .12
  3.8 Yvan Orsolini . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
  3.9 Frode Stordal . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
  3.10 Kåre Edvardsen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
  3.11 Ivar S.A. Isaksen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .13
  3.12 Bjørg Rognerud . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
  3.13 Jostein Sundet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
  3.14 Michael Gauss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14
  3.15 Ulf Peter Hoppe . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                                              3
    3.16 Eivind Thrane . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
    3.17 Berit Kjeldstad . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
    3.18 Trond Morten Thorseth . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15
    3.19 Arne Dahlback . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .15


CHAPTER 4:                    The problem                   . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16

    4.1 The Antarctic ozone hole . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
    4.2 Northern hemisphere ozone loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .16
    4.3 Modelled northern hemisphere ozone loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
    4.4 UV radiation in the troposphere and stratosphere. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .19
       4.4.1 Surface UV measurements during all weather conditions. . . . . . . . . . . . . . . . . . . . . . . .20
       4.4.2 Airborne UV measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20
       4.4.3 UV scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21
       4.4.4 Surface albedo and ozone profile effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .21


CHAPTER 5:                    Scientific objectives                            . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22

    5.1 To quantify chemical ozone loss . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
    5.2 To improve the description of mechanisms behind ozone loss . . . . . . . . . . . . . . . . . . . .22
    5.3 To better understand the processes leading to ozone loss at middle latitudes . . . . . . . .22
    5.4 To improve the predictions of future ozone change . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22
    5.5 To obtain more precise ground based UV measurements . . . . . . . . . . . . . . . . . . . . . . . .23
    5.6 To study the effect of clouds on surface UV radiation . . . . . . . . . . . . . . . . . . . . . . . . . . .24
    5.7 To measure the altitude variations of the UV radiation field . . . . . . . . . . . . . . . . . . . . .24
    5.8 UV scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .24


CHAPTER 6:                    Tasks and Methods                              . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25

    Task 1: 3-D modelling of atmospheric chemistry . . . . . . . . . . . . . . . . . . . . . . . . . . . . .25
      Activity 1.1: Further development of a global 3-D CTM for stratospheric process studies. . .28
      Activity 1.2: Long-term studies of stratospheric ozone depletion. . . . . . . . . . . . . . . . . . . . . .28
      Activity 1.3: Improvements of the stratospheric chemical transport model . . . . . . . . . . . . . .29
      Activity 1.4: Model studies of ozone loss processes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29
      Activity 1.5: Provision of meteorological data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
    Task 2: Dynamical studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
      Activity 2.1: Ozone transport and chemistry in spring and summer . . . . . . . . . . . . . . . . . . . .31
      Activity 2.2: Ozone mini-hole events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32
    Task 3: Ozonesonde observations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33



4                                                    Coordinated Ozone and UV Project. Phase 2: 2001-2002
     Activity 3.1: Climatological measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33
     Activity 3.2: Participation in international ozonesonde programmes . . . . . . . . . . . . . . . . . . .34
  Task 4: DOAS measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .36
  Task 5: Ozone lidar measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38
  Task 6: Analysis of ozone change . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
    Activity 6.1: Hemispheric data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .40
    Activity 6.2: Temporal development of the ozone mixing ratio on isentropic surfaces . . . . .41
    Activity 6.3: Comparison between modelled and observed ozone loss . . . . . . . . . . . . . . . . . .41
  Task 7: Ground based UV measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
    Activity 7.1: Direct and global UV measurements in Trondheim as part of a
                  European network. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .43
    Activity 7.2: UV radiance distribution in a sub-Arctic region . . . . . . . . . . . . . . . . . . . . . . . . .44
    Activity 7.3: Impact of broken clouds on ground based UV irradiance; measurements,
                  analyses and validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .44
    Activity 7.4: UV radiation on a vertical surface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .46
  Task 8: Airborne UV measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48
  Task 9: UV modelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
    Activity 9.1: UV scenarios . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50
  Task 10: Coordination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .51


CHAPTER 7:                  Couplings, benefits and international
                            collaboration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
  7.1 Couplings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
  7.2 Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52
  7.3 International collaboration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
     7.3.1 EU projects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53
     7.3.2 Other collaboration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .53


CHAPTER 8:                  Time schedule and milestones                                                 . . . . . . . . . . . . . . . . . . . . . .55


CHAPTER 9:                  Dissemination of results                                      . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59


CHAPTER 10: Importance for policy issues                                                           . . . . . . . . . . . . . . . . . . . . . . . . .59


CHAPTER 11: Budget                             . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .59


CHAPTER 12: References                                    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                                                 5
6   Coordinated Ozone and UV Project. Phase 2: 2001-2002
                                          How does COZUV-2 constitute a continuation of COZ-


CHAPTER 1:                       Executive Summary
1.1 How does COZUV-2 constitute a continuation of COZUV-1?
In the second phase of COZUV we take advantage of the experience gained during the two years of
the first phase. Grosso modo, the second phase of COZUV builds directly on the first phase of
COZUV, but, as explained below there are certain new elements.
Some tasks act as support for other tasks. The observations in Tasks 3, 4, 5 and 7 will therefore con-
tinue as before and take new observations of the stratosphere as often as possible; weather, light con-
ditions and funding permitting.
Other tasks/activities constitute a further development based on the developments made during the
first phase of COZUV. This is in particular the case for the modelling tasks 1 and 2.
The observational tasks 4, 5 and 7 also contain some elements of further methodological improve-
ments. In Task 4 one will try to improve the so-called air mass factors for ozone and NO2. One will
also try to calculate air mass factors for OClO and BrO. In addition there will be an attempt to detect
iodine monoxide (IO).
In Task 5 the daylight observing capability of the ozone lidar will be improved.
In Task 7 there will also be further instrumental development. Due to some delays in this task during
the first phase of COZUV one will catch up with this in the second phase. There is also a new activity
in Task 7 that deals with the UV radiation that falls on a vertical surface. This gives a more realistic
value for the amount of UV radiation that affects human beings.
In Task 8 one will continue the development of the NILU-CUBE instrument for measurements of ac-
tinic flux. These measurements will benefit the modelling work as one will get better estimates for
photolysis rates. In this respect Task 8 represents a link between the ozone and UV parts of COZUV.
Task 8 was delayed during phase 1 of COZUV and it is the aim to remedy this in phase 2.
Task 9 is completely new. Task 9 in first phase could not be carried out as planned due to the lack of
experimental data. Task 9 in phase 2 of COZUV will deal with UV scenarios. Based on ozone fields
from the 3D CTM (Task 1) one will calculate the UV climate of the future.

1.2 What do we apply for?
This project proposal encompasses all the major Norwegian research groups in the field of strat-
ospheric ozone and UV research. We apply for support for the period 1 January 2001 to 31 December
2002, i.e. for two years. The application includes manpower support to carry out the following tasks:
      1.   Investigation of the ozone layer over north polar and middle latitudes with various instru-
           mental techniques, such as spectrometers, ozonesondes, ozone lidar and frost point hy-
           grometers.
      2.   Use of a 3-D chemical transport model for interpretation of observations.
      3.   Diagnosis of chemical ozone loss through analysis of experimental observations and com-
           parison of measurements with modelling results.
      4.   Investigation of transport mechanisms between the polar vortex and middle latitudes
           through case studies found by observations close to the vortex edge.
      5.   Scenario calculations in order to investigate the consequences of temperature change in the
           stratosphere and various degrees of compliance with the Montreal protocol.
      6.   Development of methods to measure global, direct and radiance distribution of UV, to im-


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                7
Chapter 1: Executive Summary

          prove UV dose calculations derived from instruments with different characteristics, during
          all weather conditions.
     7. Measurement of vertical profiles of actinic flux with a balloon-borne instrument.
     8. Calculation of UV scenarios.
There will be close collaboration between the involved groups in order to ensure a coherent effort.

1.3 The project participants
The following researchers participate in this proposal:
From NILU: Geir O. Braathen, Frode Stordal, Arve Kylling, Bill Arlander, Britt Ann Kåstad Høiskar,
Georg Hansen, Yvan Orsolini, Bojan Bojkov, Inga Fløisand and Kåre Edvardsen.
From University of Oslo, Dept. of Geophysics: Ivar S.A. Isaksen, Bjørg Rognerud, Jostein Sundet and
Michael Gauss.
From University of Oslo, Physics Dept.: Arne Dahlback.
From NTNU: Berit Kjeldstad and Trond Morten Thorseth.
From FFI: Eivind Thrane and Ulf-Peter Hoppe.
All the partners in this proposal have many years of experience in their respective fields. All of the
participants have taken part in EU projects and five of the participants have acted (or act) as co-ordi-
nators of EU projects within the field of stratospheric ozone and UV research.

1.4 What is the problem?
The massive ozone destruction which takes place every spring in Antarctica is a well known and well
documented problem. During the last decade it has become evident that chemical depletion of ozone
also takes place inside the Arctic polar vortex. Although the amount of ozone destruction varies from
year to year, with 1998 and 1999 being years with moderate ozone destruction, there are signs that the
situation gets progressively worse, with 1995/96, 1996/97 and 1999/00 as the three worst winters so
far (CEC, 1997; Braathen, 2000). The long-term decline in ozone at middle latitudes in the Northern
Hemisphere is also a matter of great concern since it affects densely populated areas in North Amer-
ica, Asia and Europe. The mechanisms responsible for this long-term ozone decline are not known,
but it is likely that both transport and chemistry are important. There is a clear need to quantify the
role that transport and chemistry play in the observed ozone decrease. Because of the expected in-
crease in chlorine and bromine during the next few years, with a peak in the 2000-2005 time frame,
there is a risk of more severe ozone depletion in the near future. There are large uncertainties in pro-
jected future emissions of chlorine and bromine gases, with the most recent estimate showing practi-
cally no decline in the emissions over the next 10 to 20 years. This is significantly different from
previous estimates (WMO, 1995), showing that there are severe risks for ozone depletion in the future.
The cooling of the stratosphere due to increased levels of greenhouse gases increases the risk for
ozone depletion through formation of polar stratospheric clouds (PSCs). With a coupled GCM and
atmospheric chemistry model it has been predicted that the Arctic ozone layer might suffer substantial
ozone loss during the decade from 2010 to 2020 (Shindell et al., 1998).
A decrease in total ozone gives increased levels of UV radiation. This may effect both the biosphere
and the chemistry of the atmosphere. Ozone as well as clouds, aerosols and surface albedo affect the
UV radiation field. Accurate and precise measurements of all these parameters are required to elimi-
nate non-ozone effects on the UV radiation field. Furthermore, accurate modelling taking into account
all variables is needed to interpret and understand the measurements. There is a clear indication of
declining ozone levels at high latitudes. No corresponding upward trend has been reported for UV be-


8                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                   What are the scientific objectives of this proposal?


cause of too short time series and insufficient knowledge on other factors governing UV radiation. To
enable such studies there is a need for more information on instrument characteristics and how the
various instruments in Norway behave relative to each other. Factors that influence the transfer of UV
radiation through the atmosphere, such as ozone, aerosols and clouds also need to be studied in more
detail. Finally, very few measurements have been made of the UV radiation field throughout the trop-
osphere and stratosphere. Such measurements are needed both for describing the radiation field
throughout this important part of the atmosphere and for model checking purposes.

1.5 What are the scientific objectives of this proposal?
The overall scientific objectives are:
  • A. To quantify the degree and geographical extent of chemically-induced ozone loss in the Arctic and at mid-
       latitudes during the winter and spring of two consecutive years (2000-2001, 2001-2002).
  • B. To improve the quantification of ozone loss processes in the Arctic region to reduce discrepancies between
       observed and modelled decreases. This necessitates an improved description of heterogeneous processes
       taking place on polar stratospheric clouds, and a realistic description of transport processes in the region
       during situations with extensive ozone depletion.
  • C. To obtain a better understanding of the processes leading to ozone loss at mid-latitudes. This will include
       a more realistic description of the transport between the Arctic region and the mid-latitudes, and chemical
       processes responsible for the ozone loss at mid-latitudes and the transition region.
  • D. To obtain a better understanding of the role of water vapour and how this important tracer develops over
       time from year to year and during individual winters.
  • E. Use the results obtained from the above points to improve predictions of future ozone layer changes as a
       function of temperature changes (changes in climate gases) and changes in ozone depleting substances
       (ODS). This will contribute to international assessments on ozone depletion (Montreal Protocol) and cli-
       mate change (IPCC).
  • F. Derive methods for comparison of UV measurements performed with instruments with different optical
       characterisations during all weather conditions. To increase the knowledge about the UV radiance distribu-
       tion under different atmospheric conditions (e.g. broken cloud conditions). Develop a method to monitor
       the effects of broken clouds on global spectral UV irradiance measurements.
  • G. To measure the UV radiation field (actinic flux) in the troposphere and lower stratosphere to better under-
       stand the altitude variation of the UV radiation field and the effect of other factors on UV radiation.
  • H. To develop present and future UV maps for Norway based on current satellite information and ozone pre-
       dictions from chemistry models.
These objectives will be reached through a combination of measurements and modelling.

1.6 What methods will be used?
To meet the scientific objectives outlined above we propose to carry out 9 tasks or work packages:
  • A. To implement and run 3-D chemical transport models (CTMs) to study: a) The chemical loss of ozone in
       the arctic vortex, b) the ozone loss and the exchange between the vortex and mid-latitudes, and c) long-term
       (year to decades) ozone changes. To improve the description of the chemistry, particularly the heterogene-
       ous chemistry and photodissociation rates for inclusion in the 3-D CTMs.
  • B. To implement and run a high-resolution transport model in order to study the transport mechanisms be-
       tween the tropics and mid-latitudes and between the Arctic and middle latitudes. Ozone lidar measurements
       will be compared to high resolution dynamical modelling based on realistic meteorology in order to de-
       scribe the exchange of air masses between polar and middle latitudes.
  • C. To measure the vertical distribution of ozone through ozonesonde measurements from two Norwegian sites
       (Kjeller and Ørland).
  • D. To measure total columns of ozone, NO2, OClO and BrO with a UV-Visible spectrometer deployed at Ny-
       Ålesund (SAOZ) and three spectrometers located at Andøya (SYMOCS-1, SYMOCS-2 and Bentham
       DTM 300).



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                          9
Chapter 2: Introduction

  • E. To measure vertically and temporally resolved ozone profiles with an ozone lidar located at the ALOMAR
       facility at Andøya, Northern Norway.
  • F. To analyse the degree of chemical ozone loss by various techniques: 1) Through comparisons between
       measurements and model results. Data from satellites and various international networks will be used in
       addition to the Norwegian data. Observations will be compared to both chemically active model runs and
       passive model runs, where the chemistry is turned off; 2) Through analysis of the ozone mixing ratio from
       sonde and lidar data at isentropic levels. The degree of ozone loss caused by lee-wave PSCs will be as-
       sessed.
  • G. To measure simultaneously direct and global spectral UV irradiance. A sun tracker will be further devel-
       oped to measure polarised and unpolarised radiance in all directions. Rapid changes in cloud conditions
       will be followed by fast multichannel measurements. Correction of data due to different instrument char-
       acterisation and other quality control procedures will be done. Comparison between different UV measure-
       ments and available models will be performed.
  • H. To launch balloons carrying a twelve-channel NILU-CUBE instrument to measure the UV radiation field
       throughout the troposphere and lower stratosphere.
  • I. To use ozone, surface albedo and cloud information from the TOMS satellite instrument to derive UV doses
       for the present situation, and use ozone fields predicted by chemistry models together with cloud and sur-
       face albedo information from TOMS to estimate future UV doses.

1.7 Time schedule
We apply for a two year project starting in 2001 and lasting through 2002. A detailed time schedule
and milestones have been defined for the project. These are described in chapter 7.

1.8 How will the results be disseminated?
The data and results from this project will be disseminated through publications in peer-reviewed sci-
entific journals, progress reports to the Norwegian Research Council, participation in international
conferences, information to the environmental authorities, and through information on the World
Wide Web. There will also be an emphasis on the exchange of data between the partners of the project.

1.9 Policy issues
The results from this project will give policy-makers the necessary basis for negotiations on revisions
of the Montreal Protocol. The writing of IPCCs Third Assessment Report (TAR) started in 1999 and
finishes in 2001. Ozone as a climate gas is likely to get more attention than in previous assessment
reports, particularly changes of ozone in the tropopause region. The COZUV project will contribute
to this assessment.


CHAPTER 2:                          Introduction
This joint proposal is a result of cooperation between six research groups (four institutions) that have
been actively involved in ozone and UV research for several years. The participating institutions are
the following: NILU, FFI, UiO and NTNU. In chapter 3 a short description of all responsible scientists
are given. Chapters 4-6 describe the real content of the project. Chapter 7 explains the benefits of a
joint Norwegian project and summarises all the relevant cooperation between different groups and in-
stitutions within the project as well as international cooperation.
The project will be coordinated through meetings and half-yearly reports. The responsible scientist
for each task will coordinate the activities within a task. They report to the coordinator of the project.
Plans for the coordination work and progress are given in Chapter 8. Details of the budget,
3.53 MNOK in 2001 and 3.45 MNOK in 2002, is given in chapter 11.



10                                        Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                   Geir O. Braathen


CHAPTER 3:                       The applicants’ knowledge of
                                 the field
Complete CVs with publications lists have been enclosed. The following sections give a brief sum-
mary of the participants’ experience.

3.1 Geir O. Braathen
The coordinator of this application, Dr. Geir O. Braathen, has twelve years of experience in the field
of stratospheric ozone research, with emphasis on ozonesonde observations and ozonesonde data
analysis. During the European Arctic Stratospheric Ozone Experiment (EASOE) in 1991-92 he was
responsible for the scientific coordination of the 20 participating sonde stations. Computer software
was developed at NILU in order to ensure that sonde data was submitted in a standard format, and a
program was made to convert ozonesonde raw data into quality checked homogeneous geophysical
data.
Geir Braathen was also responsible for the scientific coordination of the ozonesonde activities during
the Second European Stratospheric Arctic and Mid-latitude Experiment (SESAME). This work in-
volves coordination of launches during special episodes and ensuring that the collected ozonesonde
data constitute a high quality homogeneous data set. From 1996-98 he coordinated the EU project
OSDOC, a project that aimed at detecting ozone loss with the use of ozonesondes.
Currently he is the coordinator of the EU projects “Third European Stratospheric Experiment on
Ozone – Ozone Loss in the Arctic and at Mid-Latitudes” (THESEO-O3LOSS) and THESEO 2000 -
EuroSOLVE. He has developed routines for real time submission of sonde data, and he has led the
development of a program for ensuring that the ozonesonde data form a homogeneous data set. The
project leader is member of the Steering Committee of the Network for the Detection of Stratospheric
Change (NDSC), where he is the primary representative for the ozonesonde activities. He has pub-
lished and participated in several publications on the use of ozonesonde data for the detection of
chemical ozone loss.
In 1993-94 he was co-author for the chapter on Polar Ozone in the WMO/UNEP scientific assessment
of stratospheric ozone. He was the lead author on the Stratospheric Ozone chapter of the second report
on Europe’s Environment that was prepared by the European Environment Agency (the Dobis+3 re-
port). During the summer of 1997 he acted as the referee for a lidar instrument intercomparison taking
place in southern France as part of the continuous NDSC effort to ensure homogeneous data. In April
2000 he was the convener of the polar ozone session at the 25th General Assembly of the European
Geophysical Society.

3.2 Bill Arlander
Dr. D. William Arlander has over 10 years experience at several institutes in Europe and the USA in
instrumentation development, calibration, in-field deployment and data interpretation relevant to
stratospheric and tropospheric chemistry. He has been employed at NILU since 1996 where he has
been working on UV/visible/IR remote sensing instrumentation development for tropospheric and
stratospheric measurement programmes in Scandinavia. He has actively participated in numerous EU
measurement programmes including EASOE, ESMOS-Alps, ESMOS-Arctic, ESMOS-II, SESAME,
SCUVS-3 and THESEO at several European NDSC sites. He will also be the co-ordinator of the EU
funded QUILT project (Quantification and Interpretation of Long-Term UV-Vis Observations of the
Stratosphere).




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                              11
Chapter 3: The applicants’ knowledge of the field


3.3 Bojan Bojkov
Dr. Bojan R. Bojkov holds a position as senior scientist and manages NILU’s Atmospheric Database
for Interactive Retrieval. He has a Ph.D. in numerical analysis from 1994 and has more than 10 papers
in peer-reviewed journals as well as numerous conference presentations. Research experience and ex-
pertise: Bojan R. Bojkov has 4 years experience in the launching of ozonesondes and the evaluation
and analysis of ozonesonde data. He has been responsible for the operations of the NADIR data centre
since 1996 and has recently established the World Data Centre for Surface Ozone (WDCSO3) and the
WMO/GAW Regional Centre for Ozonesonde Collection. He is currently implementing on behalf of
the European Space Agency (ESA) a relational database for the validation of four environmental in-
struments to be flown on the ENVISAT satellite.

3.4 Inga Fløisand
Dr. Inga Fløisand has worked in the field of atmospheric chemistry since 1992. Her main focus has
been modelling of heterogeneous chemistry in the stratosphere. A photochemical trajectory model has
been used to study heterogeneous processing and the effects on ozone abundance compared to obser-
vations. She has participated in several EU projects (e.g. under the EASOE, SESAME and THESEO
campaigns and ESMOS/Arctic I&II, LAMOCS, POLINAT II, SAMMOA).

3.5 Georg Hansen
Dr. Georg Hansen has worked in the field of middle atmosphere and ionosphere physics since 1986.
The main subjects of his research are layer phenomena and dynamics in the stratosphere, mesosphere
and the lower ionosphere. He has 11 years of experience with the lidar technique, 3 years with inco-
herent radar technique, and 6 years with various techniques of total ozone monitoring. Since 1994 he
has been working at NILU, being responsible for the Norwegian ozone and UV monitoring pro-
gramme in the Arctic, in particular for the activities related to the ozone lidar and other ozone/UV-
monitoring instruments at ALOMAR. He is co-ordinator of the EU project UVAC, a marine UV im-
pact study, and participant in two other EU projects (EUROSOLVE, SAMMOA) related to strat-
ospheric ozone research.
Dr. Hansen has also 5 years of experience in satellite validation; he is responsible for the Norwegian
GOME validation/calibration projects and will be involved in ENVISAT validation as well.

3.6 Britt Ann Kåstad Høiskar
Dr. Britt Ann Kåstad Høiskar has worked in the field of atmospheric physics since 1992. Her main
focus has been UV/visible remote sensing in the stratosphere. She will be responsible for the instal-
lation, maintenance and data analysis of the UV/Vis spectrometer stationed at Ny-Ålesund. She is cur-
rently involved in the development of the NILU-UV instrument, and will be working with instrument
characterisation and data quality analysis. She has participated in several EU projects (e.g. STEP013,
SCUVS1-3, EASOE, SESAME, THESEO) and NDSC measurement campaigns.

3.7 Arve Kylling
Dr. Arve Kylling is a research scientist at NILU, Norway. He has 12 years of experience with radiative
transfer modelling. Radiative transfer models have been used to study UV and IR radiation throughout
the atmosphere both for sensitivity studies and for comparison with measurements. Currently, focus
is on calculation of the actinic flux available for photolysis in the troposphere and the biologically rel-
evant surface UV-irradiance. Furthermore, comparison of these quantities with measurements under
a variety of atmospheric conditions is being performed. Research is also done on how to derive im-
portant parameters such as aerosol single scattering albedo, surface albedo, and cloud amount, and
how these parameters affect the UV radiation field. He has participated in the EC funded projects SU-


12                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                            Yvan Orsolini


VDAMA, UVRAPPF, PAUR and MAUVE, and presently participates in the ADMIRA and EDUCE
projects.

3.8 Yvan Orsolini
Dr. Yvan Orsolini has obtained his PhD from the University of Washington in 1991, and has been
working on middle atmosphere dynamics and chemistry at Meteo-France (Toulouse) until March
1998, when he joined NILU. He has been involved with modelling and data analysis during the Eu-
ropean campaigns EASOE and SESAME, and participates to the on-going THESEO campaign. His
research has focused on transport of trace species in the stratosphere with high-resolution transport
models and general circulation models, and on interpretation of satellite, aircraft and ground-based
measurements. He has published several papers on UARS data analyses, and will participate in the
ENVISAT data validation. He has collaborated for several years with the ALOMAR ozone lidar
group. He has led the NILU contribution to the EU TOPOZ-II project and the modelling contribution
to the METRO project. He is also the coordinator of the EU project SAMMOA (Summer to Autumn
Measurements and Modelling of Ozone and Active Species). The SAMMOA consortium is made up
of 9 leading European institutes in the field of ozone research.

3.9 Frode Stordal
Professor Frode Stordal is senior scientist at NILU. From 1995-1999 he was head of the Department
of regional and global issues at NILU. He also holds a position as professor at the University of Oslo.
He was actively involved in EASOE e.g. as member of the EASOE Core Group. He was also a PI in
NASA’s Airborne Arctic Stratospheric Experiment (AASE) in 1989. He has been involved in WMO
ozone assessments since 1985, and also contributed to the IPCC reports. Stordal has been a PI in sev-
eral EU projects, within the fields of stratospheric chemistry (e.g. MOSTOZ, EHCSTRA, PVC), trop-
ospheric chemistry (OCTA, ARCTOC, TACIA, HALOTROP, NICE, POET), effects of aircraft
(AERONOX, POLINAT, POLINAT-2, AEROCHEM, AEROCHEM-2, TRADEOFF) and climate
(ROCS). He also holds a part time position as a professor at the University of Oslo, where he teaches
classes in atmospheric chemistry and modelling.

3.10 Kåre Edvardsen
Kåre Edvardsen has worked in the field of stratospheric ozone and UV-radiation since 1997. He has
5 years of experience with spectroscopy technique, 3 years with broad band UV and visible filter in-
struments, and some experience in the LIDAR technique. At NILU, he has been involved in the de-
velopment of instruments for use in the field of UV and ozone measurements. He is also responsible
for the calibration and validation of the Brewer ozone measurements at ALOMAR. The last three
years he has participated in several EU projects: CASSIS, MAUVE and UVAC (ongoing).

3.11 Ivar S.A. Isaksen
Ivar S.A. Isaksen is professor in meteorology at the University of Oslo. His area of research is atmos-
pheric chemistry, and he has more than 20 years of experience in modelling of chemical gases in the
atmosphere. The emphasis of the modelling activities has been on ozone depletion and changes in
chemical active greenhouse gases from man-made emissions. He is leading a group at the department
of Geophysics that during the last 7 years have focused on developing and applying 3-D CTMs to
study tropospheric and stratospheric ozone, and other chemical compounds affected by man-made ac-
tivities. This research has resulted in several articles that have been published in international journals.
He has participated in several international research project where the focus has been on stratospheric
ozone and ozone depletion (coordinated through EC or US Agencies; NASA, DOE, EPA). He has co-
ordinated three previous EC (STEP programme, Environment and Climate programme) projects. He


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                   13
Chapter 3: The applicants’ knowledge of the field

is currently coordinating a project, TRADEOFF, where the focus is on aircraft impact on the upper
troposphere and lower stratosphere. The focus was on lower stratospheric and upper tropospheric
ozone, and is currently coordinating the AEROCHEM II project which is a follow up of the AERO-
CHEM I project and is studying impact of aircraft emissions in the upper troposphere and lower strat-
osphere. He has coordinated a joint Nordic project and a Norwegian project on ozone as a climate gas.
Professor Isaksen has been active in international assessments on ozone depletion and climate chang-
es. He has been lead author of the international ozone assessments organised since 1995 by WMO,
and was a reviewer of most recent (1998) international assessment. He was a lead author of the 1992
and 1995 IPCC climate assessments and is a lead author of the current (1998) IPCC assessment of
aircraft impact. He is currently the lead author of the 2001 IPCC climate assessment. He has been the
co-author of two recent assessment organised by EU; one on Arctic ozone depletion (1997), and one
on the impact of aircraft emissions (1998). He has organised several workshops on ozone and related
issues.
He is a member of several committees, which is of relevance for the ozone depletion issue, for in-
stance: Chairman of the WMO scientific advisory group on ozone, member of the committee for the
European program on stratospheric research, member of the International Ozone Commission.

3.12 Bjørg Rognerud
Cand. real. Bjørg Rognerud has more than 12 years of experience in modelling of stratospheric ozone.
She is now working at the Department of geophysics, University of Oslo, as scientist and is working
both with two- and three-dimensional stratospheric models developed at the institute. She has been
contributor to different WMO assessments, and she has also worked in various EC projects, such as
TOPOZ, SAONAS, PVC, that has special relevance for the project.

3.13 Jostein Sundet
Dr. scient. Jostein Sundet has experience in developing and using Chemical Tracer Models (CTM).
For his PhD thesis he developed a general CTM where the model core is applicable both in strat-
ospheric and tropospheric chemical modelling. Currently he is a Post. Doc. at Dept. of Geophysics,
UiO and is working with global three-dimensional tropospheric modelling. He has participated in a
number of EU projects.

3.14 Michael Gauss
Michael Gauss has 3 years experience in modelling chemical species in the atmosphere. He took his
master degree in Meteorology in 1998. The subject of his master thesis was to further develop a strat-
ospheric chemical transport model and to study the impact of aircraft emissions upon the atmosphere.
After his master degree he worked as a research fellow in the group of Prof. Ivar S.A. Isaksen and was
involved in various EU projects. Since 1999 he is a Ph.D. student supervised by Ivar S.A. Isaksen and
works primarily with the inclusion of stratospheric chemistry in a chemical transport model.

3.15 Ulf Peter Hoppe
Ulf-Peter Hoppe Dr. U.-P. Hoppe is a principal scientist with professor competence at FFI. He com-
pleted his doctor’s degree at Bonn University in 1985, after working with a Na temperature lidar for
three years. He was project manager of the space physics group at FFI in 1992 and 1993. He was the
project scientist of FFI’s rocketborne Rayleigh lidar (TROLL), which was launched successfully in
October 1997 and January 1998. He has been project scientist of the ALOMAR ozone lidar since
1994, jointly with Dr. G. Hansen since 1995. Hoppe has been external supervisor of four master’s stu-
dents of physics at the University of Oslo, who have completed their exams in 1988, 1990, 1992, and



14                                    Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                      Eivind Thrane


2000, as well as two master’s students of physics at the University of Trondheim (1999 and 2000). He
has been teaching a graduate course on Lidar Remote Sensing from Satellite Platforms at the Centre
for Technology at Kjeller (UNIK) since 1991, and part of a course on the Middle Polar Atmosphere
at the University Courses on Svalbard (UNIS) since 1995. In January 2000 he was elected Chairman
of the ALOMAR Board of Directors for three years.

3.16 Eivind Thrane
Prof. Eivind Thrane has been employed at the Norwegian Defence Research Establishment since
1962. Since 1995 he holds the position of Chief Scientist. Since 1985 also holds a part time position
as a professor at the University of Oslo. Prof. Thrane has concentrated on basic research within the
field of radio wave propagation in the ionosphere, plasma- and auroral physics and the physics of the
middle atmosphere. He has more than 20 years experience as project manager at the FFI and at present
leads a group of nine scientists and six engineers.

3.17 Berit Kjeldstad
Associate prof. Berit Kjeldstad has been working within the field of UV science since 1982. Since
1992 focus of her research has been on solar UV radiation and atmospheric processes effecting natural
UV levels in nature and processes influencing UV doses. Most of the work has been related to solar
UV measurements and quality control of data both in atmosphere and ocean. She has been coordinator
of one large Nordic intercomparison in 1996 were 17 groups from the Nordic countries and Europe
participated. During last 5 years she has been supervising eight master students within this field and
one PhD student, Thorseth, currently working as a postdoc on COZUV. She has participated in previ-
ous EU projects as SUSPEN and SUVDAMA. Currently she is participating in a new 3 year EU
project, EDUCE.

3.18 Trond Morten Thorseth
Thorseth is currently a postdoc at the Department of physics, NTNU. He finished his PhD April 2000.
He has been working on instrument characterisation, data quality analysis and comparison with mod-
elled data. He has participated in several meetings, three intercomparisons and workshops and in the
EU funded project SUVDAMA.

3.19 Arne Dahlback
Professor Arne Dahlback is head of the Plasma and Space Physics Group at the Department of Phys-
ics, University of Oslo. He has 15 years of experience with radiative transfer modelling, UV and ozone
measurements. Radiative transfer models have been used to derive optical parameters from spectro-
radiometers and particularly multi-channel filter instruments for measurements of solar UV radiation.
He has established a UV monitoring network in Chile funded by the Norwegian Ministry of Environ-
ment and was strongly involved in the establishment of the Norwegian UV network. A method to de-
rive biological effective UV radiation, cloud effects and total ozone abundance (Dahlback, 1996) has
been developed and is used to analyse data from the Norwegian UV monitoring network as well as
the UV network in Chile. He has also for many years been involved in work related to skin cancer and
UV radiation.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                             15
Chapter 4: The problem


CHAPTER 4:                        The problem
4.1 The Antarctic ozone hole
The chemical and physical processes leading to the ozone destruction in the Antarctic ozone hole are
fairly well understood. It is generally agreed in the scientific community that man-made halogen con-
taining substances, such as chlorofluorocarbons and halons, play an essential role together with polar
stratospheric clouds (PSCs) in the destruction of stratospheric ozone.

4.2 Northern hemisphere ozone loss
After the discovery of the Antarctic ozone hole in 1985 it became apparent that the ozone layer in the
Arctic has suffered depletion since the 1970s, as well.
In the Arctic stratosphere PSC condensation temperatures are not as common and widespread as in
Antarctica, but almost every winter PSCs of type Ia (HNO3 ·3H2O) are observed. Type II PSCs (pure
water ice) are much less common and are rarely observed. Measurements from the ground, from bal-
loons, from aircraft and from satellites show that active chlorine (ClO) exists in mixing ratios of more
than 1ppb and even up to 2 ppb during the winter and spring in the Arctic (Figure 1). This is compa-
rable to the mixing ratios found in the Antarctic vortex. The largest difference between the two polar
regions is that the Arctic stratosphere does not stay cold as long as its Antarctic counterpart, thus lim-
iting the time period available for the ozone destroying reactions.
After several winters during the last decade (1992-93, 1994-95, 1995-96, 1996-97 and 1999-00) that
have experienced unusually low temperatures, there is no longer any doubt that extensive ozone de-
pletion can and does take place in the Arctic. In certain height regions as much as 70% of the ozone
was missing compared to earlier winters (Braathen et al., 1999, 2000). Modelling carried out in Nor-
way and by other research groups confirm that the observed ozone loss is caused by man-made halo-

                                                                           Figure 1.
                                                                           Temperature data (left) and
                                                                           observed chlorine monoxide
                                                                           (ClO) from the satellite borne
                                                                           instrument MLS (Microwave
                                                                           Limb Sounder) on board the
                                                                           Upper Atmosphere Research
                                                                           Satellite (UARS). The dates
                                                                           15 Feb. 1992 and 15 Feb. 1993
                                                                           have been compared. It is seen
                                                                           that the lower temperatures in
                                                                           1993 lead to higher concentra-
                                                                           tions of ClO. Mixing ratios
                                                                           around 2ppb are observed in
                                                                           1993. This is comparable to
                                                                           the mixing ratios of ClO found
                                                                           during the Antarctic spring.




16                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                Northern hemisphere ozone loss




            1980                              1988                             1992




             1993                           1997                               1998
                                         Dobson Units
                                              Above 460        Figure 2. These six maps show how
                                                               the monthly mean total ozone for the
                                                440 - 460      month of March has declined during
                                                420 - 440      the time period from 1980 to 2000. The
                                                               first four maps are based on TOMS
                                                400 - 420
                                                               data from Nimbus 7 and the last three
                                                380 - 400      map are based on TOMS data from the
                                                360 - 380      NASA Earth Probe.
                                                340 - 360
                                                320 - 340
            2000                                300 - 320
                                              Below 300

gen compounds. The three winters mentioned above were unusually cold, and although it is too early
to speak about a temperature trend, one can see a tendency towards a cooling of the Arctic strato-
sphere. The polar vortex lasted longer than ever in 1997, breaking up as late as around 10 May
(Hansen and Chipperfield, 1999). Satellite data show clearly how the total ozone column at high lat-
itudes has declined since 1980. Figure 2 shows maps based on data from the TOMS instrument on-
board Nimbus 7 and the Earth Probe, illustrating how March average ozone has developed between
1980 and 2000.
It is also seen that the ozone amount in 1998 was quite similar to the situation in 1992. This is ex-
plained by the fact that the 1997-98 winter was much milder than the three previous winters, with
much fewer episodes of PSCs and hence less formation of active chlorine and bromine species. The
high ozone values in 1998 strengthen the theory that Arctic ozone depletion is caused by a combina-
tion of halogens and low temperatures. The winter 1999-2000 was cold and was quite similar to the
1995-96 winter, except that the cold region was more shallow in 2000. This led to substantial ozone


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                    17
Chapter 4: The problem

loss around 18-19km, but the loss in the total column was somewhat less severe.
The increase in vortex strength and its longer duration into the spring is illustrated in Figure 3. During
the spring of 1997 the vortex was especially strong, but one can also see that the vortex longevity has
increased more or less steadily during the time period from 1980 to 2000. See figure caption for ex-
planation of the plotted parameter.

                                       9                                                                                        9
                              1.5*10                                              Year                                 1.5*10
                                           1980-1985                               1985                                             1986-1990                              Year
                                                                                   1984                                                                                     1990
  Vortex strength [PV*area]




                                                                                           Vortex strength [PV*area]
                                                                                   1983                                                                                     1989
                                       9
                                                                                   1982                                         9
                                                                                                                                                                            1988
                              1.0*10                                               1981                                1.0*10                                               1987
                                                                                   1980                                                                                     1986
                                                                                   Max                                                                                      Max

                                       8                                                                                        8
                              5.0*10                                                                                   5.0*10




                                       0                                                                                        0
                              0.0*10                                                                                   0.0*10
                                           -50   -25   0    25          50   75    100                                              -50   -25   0    25          50   75    100
                                                           Julian day                                                                               Julian day


                                       9                                                                                        9
                              1.5*10                                                                                   1.5*10                                               Year
                                           1991-1995
                                                                                   Year
                                                                                    1995
                                                                                    1994
                                                                                                                                    1996-2000                                2000
                                                                                                                                                                             1999
                                                                                    1993                                                                                     1998
                                                                                    1992                                                                                     1997
                                                                                           Vortex strength [PV*area]
  Vortex strength [PV*area]




                                                                                    1991                                                                                     1996
                                                                                    Max                                                                                      Max
                                       9                                                                                        9
                              1.0*10                                                                                   1.0*10




                                       8                                                                                        8
                              5.0*10                                                                                   5.0*10




                                       0                                                                                        0
                              0.0*10                                                                                   0.0*10
                                           -50   -25   0    25          50   75    100                                              -50   -25   0    25          50   75    100
                                                           Julian day                                                                               Julian day


   Figure 3. Temporal development of a vortex strength indicator from 1980 to 2000. This indicator is calculated by
   adding the product of the PV value by the area of grid cells for all grid cells where PV is larger than a certain value.
   At the level of 475K this threshold has been set to 36⋅10-6Km2/kgs. It is clearly seen that the vortex strength has in-
   creased during this time period, esp. in the late spring (March and April). The blue thick curve (identical in all four
   panels) represents the maximum vortex strength for each day during the 21 year period from 1980-2000.


Also over middle latitudes there is a significant decline in total ozone. Part of the long-term decline
in mid-latitude ozone can probably be explained by an increasing loss in the vortex and some might
be explained by processing occurring at mid-latitudes. A third possible mechanism is chlorine activa-
tion on extravortical PSCs, which are frequent during Northern Hemisphere winters. One of the out-
standing questions of stratospheric ozone research is to quantify the relative importance of these three
different mechanisms.
Another problem of prime importance is the fact that models underestimate the ozone loss rate inside
the polar vortex. Both these questions will be addressed by the present proposal.
Ozonesonde, groundbased and satellite observations in combination with 3-D chemical and dynami-
cal modelling and data analysis will help us to understand the role of these processes in middle latitude
ozone loss.
In order to understand the coupling processes linking the stratosphere to the regions above, it is nec-
essary also to study the state of the mesosphere and lower thermosphere. In particular, the high latitude
mesopause region is of interest, because the temperature at this level may be a sensitive indicator of


18                                                                           Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                        Modelled northern hemisphere ozone loss


trends caused by global warming. Existing facilities, such as ALOMAR, will provide information that
can support the observations and modelling outlined in this proposal.

4.3 Modelled northern hemisphere ozone loss
Two sets of models are basically used to study ozone processes and depletion in the lower strato-
sphere. 2-D models which are computationally efficient thus allowing them to incorporate detailed
representation of the chemistry and radiative processes, and zonal mean dynamics. Their main advan-
tage is that they are capable of making long-term (decades) integrations. These models are therefore
widely used for assessment studies, such as the most recent ozone assessment (WMO, 1999). They
have been improved during the last few years to include complex heterogeneous chemistry and can to
some degree reproduce the large ozone loss in the southern vortex, and enhanced ozone loss observed
in the Northern Polar vortex after the El Chichón and Mt. Pinatubo eruptions (Solomon et al., 1996).
Several studies have been performed to simulate mid-latitude ozone on a 10 to 20 year time scale (end
of 1970s to present time) using 2-D models (Solomon et al., 1996; Jackman et al., 1996; Zerefos et
al., 1997; Solomon et al., 1998). The models seem to capture some of the main features observed dur-
ing the 1990s: the decrease after the Mt. Pinatubo eruption in 1991, increasing loss from chlorine re-
actions due to low temperatures and enhanced PSC formation, and a possible effect from the 11 year
solar cycle variation. Yet, a general trend in the model results seems to be a clear underestimate of the
observed ozone decrease. It is clear from these studies that 2-D models have strong limitations when
it comes to estimating mid-latitude ozone loss due to their poor representation of the processes in-
volved in polar vortex break-up and stratosphere/troposphere exchange.
The 3-D CTMs have been successful in reproducing many of the features of the observed ozone dis-
tribution. There is, however, evidence that these models still underestimate the winter/spring ozone
depletion at high latitudes. For instance, Hansen et al. (1997) compared observations from Andøya
during the 1995/1996 Arctic winter with 3-D CTM calculations using UKMO analyses. Although the
model in general gave good agreement it underestimated the observed ozone loss by up to 50% near
18 km in late March. Several detailed studies have been performed recently (Carslaw et al.1995; Rex
et al, 1997) to find the reason for this discrepancy, but all known mechanisms seems to fail. It appears
that the problem arises in January in the presence of strong PSCs. There are several reasons why mod-
els may underestimate ozone loss. Some of the reasons that have been suggested are: Not enough de-
scent at high latitudes of high levels of inorganic chlorine and bromine, there are indications of too
low levels compared to observations; insufficient chlorine and bromine activation, this process is sen-
sitive to the temperature which seems to be too high according to Knudsen (1996); laboratory data are
still connected with uncertainties that affect the computed loss rates. In addition, the models, despite
large improvements over the last few years, still have a highly parameterised treatment of the micro-
physical processes since such codes are expensive to include. One of the main tasks in this proposal
is to further develop and apply a 3-D CTM that can be used to interpret observations and analyse proc-
esses. During the model development uncertainties discussed above will be addressed.
There are still outstanding discrepancies between model prediction and observations of the year-round
stratospheric ozone decline at middle and high latitudes. In summer, current models still severely
overestimate ozone in the polar regions, and this appears as a major deficiency in our ability to model
the complete ozone seasonal cycle. Modelling improvements of ozone loss processes throughout
spring and summer in the northern mid and high latitudes, are still needed in order to predict ozone
trend and recovery in support of regulatory protocols.

4.4 UV radiation in the troposphere and stratosphere.
A decrease in total ozone results in increased levels of UV radiation. This may affect both the bio-
sphere and the chemistry in the atmosphere. While downward ozone trends have been clearly detect-



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                19
Chapter 4: The problem

ed, there is no clear evidence for upward UV trends. This is caused mainly by the lack of precise and
accurate long-term UV radiation measurements and the corresponding problems involved in making
such measurements. Furthermore, upward UV radiation trends may be outweighed by trends in aero-
sol concentrations or cloud cover. In addition, the surface albedo affect the UV radiation field. Hence,
to understand the behaviour of the UV radiation field and the factors controlling the UV radiation
field, independent measurements of these quantities are needed in addition to accurate and precise UV
radiation measurements.
Surface measurements of the UV radiation field are now at a level of accuracy that allows for trend
detection, provided the time series is long enough. Measurements of UV radiation throughout the
troposphere and lower stratosphere are sparse and little is known of the behaviour of the UV radiation
field with altitude and how various factors affect it.
Biologist and health personal are in need of estimates of present and future UV levels both to under-
stand the implications of the present UV levels and assess future risks.

4.4.1 Surface UV measurements during all weather conditions.
Global UV irradiance is monitored all over the world with different types of instruments. Continuous
work is done to increase our knowledge about the instrumentation, uncertainties and how different in-
strumental characteristics influence the results. Several large international intercomparisons between
different instruments have been performed (Kjeldstad et al. 1997, Early et al. 1998, Thompson et al.
1997). The results indicate that it is still a scientific challenge to compare UV measurements from dif-
ferent types of instruments, even if the influence of important parameters such as irradiance scale cal-
ibration with standard lamps, wavelength calibration and correction, and slit function effects have
been carefully studied. Some instruments may deviate by as much as 15-20% at high solar zenith an-
gles during clear sky situations. There is not much information available during completely overcast
conditions nor broken cloud conditions which are even more difficult to handle. Results from all
weather measurements performed in Trondheim with a spectroradiometer and a filter instrument have
shown that the problems are large when comparing during rapid cloud changes, a typical situation at
our latitudes (Thorseth et al. 1998). Spectral measurements during variable cloud conditions need to
be corrected for cloud effects. During a scan the radiation levels might typically oscillate by more than
50% due to rapid cloud changes.
One critical factor identified at several intercomparisons, which might give large deviations between
different instruments, is the effect of different cosine response function of the instruments (Blumthaler
and Bais, 1997). Large improvements between instruments can be achieved if the measurements are
corrected with a cosine correction factor valid for the instruments under that specific weather condi-
tion. The cosine response depends mostly on the shape of the diffuser. These have currently been im-
proved for many spectroradiometers. However, most of the global UV networks are based on narrow
band multichannel or broad band filter instruments, with a less perfect cosine response. They have al-
ready measured UV for several years, some even for a couple of decades. These measurements have
to be compared and controlled with high quality spectral measurements. Cosine correction methods
will be critical for real comparisons between these network instruments and spectral measurements.
Most of the radiative transfer calculations do not take into account the effect of polarised light scat-
tered. This may introduce errors in the radiance as large as 10% (Lacis et al., 1998). There is currently
not much information available about the amount of polarised UV radiation at different solar zenith
angles.

4.4.2 Airborne UV measurements.
In situ measurements of the UV radiation field in the troposphere and the stratosphere are rare. Van


20                                     Coordinated Ozone and UV Project Phase 2: 2001-2002
                                               UV radiation in the troposphere and stratosphere.


der Hage et al. (1994) have developed an instrument to measure the actinic flux. It has been flown on
a tethered balloon up to approximately 1600m both during clear and cloudy situations (Vil‘a-Gurea
de Arellano et al., 1994). Schiller et al. (1994) have reported actinic flux measurements in the strato-
sphere. The above instruments measured the actinic flux in a single wavelength interval. There is thus
a lack of experimental information about the UV radiation profile and its spectral behaviour in the
troposphere and stratosphere. Furthermore, directional information about the UV radiation field is
missing. To remedy this situation, balloon measurements with a UV filter instrument will be carried
out during the current phase of COZUV and continued in the next phase, as described in Task 8.

4.4.3 UV scenarios
Present chemistry-climate simulations predict that the ozone levels will decrease in the near future.
This decrease will be largest at high latitudes and will lead to higher UV doses if all other factors af-
fecting UV radiation remain unchanged. To enable biologist and physicians to estimate the present
and future effects of UV radiation, maps of UV radiation at various temporal and spatial scales are
needed. The maps must be compared with surface measurements where available and error estimates
included.

4.4.4 Surface albedo and ozone profile effects
Strong surface reflection, e.g. from snow, has a significant effect on atmospheric UV radiation due to
multiple reflections between the surface and the atmosphere. Sloping terrain changes the illumination
geometries, and thus the reflection of radiation. All natural surfaces are to some extent horizontally
inhomogeneous, with a sloping terrain. In order to estimate the influence of the surface using a plane-
parallel radiative transfer model, an “effective” surface albedo must be known. The “effective” albedo
is a weighted average of all the different surfaces in the vicinity. The weights as well as the meaning
of “vicinity” must be assessed. The “effective” albedo depends on the radiation transfer in the atmos-
phere, where an accurate quantification of horizontal propagation of radiation is particularly impor-
tant. The problem of horizontally inhomogeneous surfaces can be solved by three-dimensional
radiative transfer models. However, it is necessary to truncate the radiative regime in the horizontal
direction due to computational constraints.
The absorption of ozone in the atmosphere is dependent on atmospheric temperature and scattering.
Because the two latter elements are highly variable with respect to altitude, the ozone profile has an
effect on the surface UV radiation.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                21
Chapter 5: Scientific objectives


CHAPTER 5:                        Scientific objectives
5.1 To quantify chemical ozone loss
One important scientific objective is to quantify the degree and geographical extent of the ozone loss
that takes place both inside and outside the polar vortex during the two winters of 2000-01 and 2001-
2002. Several of the most recent winters have experienced significant chemical ozone loss, and the
situation tends to get progressively worse. It is therefore important to keep an eye on the situation over
the next few years as the chlorine and bromine loadings continue to increase and reach the maximum
in the 2000-2005 time frame. In addition to the increase in the concentration of halogen compounds,
one has witnessed a cooling of the Arctic stratosphere and an increase in the longevity of the polar
vortex. In 1997, the polar vortex existed until around 10 May, which is exceptionally late. In terms of
vortex climatology a picture that resembles the conditions in Antarctica is emerging. If the tendency
towards lower temperatures in the stratosphere should continue during the coming years there is a real
risk that an ozone hole can emerge in the Arctic. It is therefore important to assess the relative impor-
tance of chemical factors (such as the increase in the halogen concentration) and dynamical/climato-
logical factors (such as temperature conditions and duration and position of the polar vortex).
The study of layered structures such as PSCs and their relation to ozone distribution and the dynamics
and temperature structure in the high latitude stratosphere and mesosphere may yield important clues
to our understanding of climatic trends (Thomas, 1996). The present proposal will therefore aim at
using available observations to map the presence of such structures. The comprehensive instrumenta-
tion available at the ALOMAR facility offers opportunities for such studies.

5.2 To improve the description of mechanisms behind ozone loss
Although the scientific community has obtained a broad and rough understanding of the processes
leading to ozone depletion, there are still many details that need further investigation. It has also be-
come evident during some of the winters of the last decade that atmospheric chemistry models under-
estimate the degree of ozone loss inside the polar vortex. Simulations of the ozone field for regions
and time periods where there is little or no ozone depletion show a remarkable agreement with obser-
vations. On the other hand, when there is substantial ozone depletion, the models clearly underesti-
mate the degree of ozone loss. Figure 4 shows an example of a comparison between measured and
modelled ozone in March 1996.

5.3 To better understand the processes leading to ozone loss at middle latitudes
The ability of CTMs to represent transport processes in the low latitudes needs to be assessed. It is
particularly important to know whether the relatively unmixed ascent of trace species throughout the
lower tropical stratosphere, as diagnosed from satellite observations, can be modelled.
In addition, improvement of our knowledge of the mechanisms involved in the meridional transport
of air from high latitudes into mid-latitudes, especially at small scales are much needed. The ability
of high resolution numerical models to simulate the formation and temporal development of filaments
and laminae, as frequently observed by the ALOMAR ozone lidar in Andøya (Northern Norway), will
be examined. The chemical implications of these mixing processes need to be better understood, by
the combined use of high-resolution advection models, chemical box models and observations.

5.4 To improve the predictions of future ozone change
During the last years increased efforts have been put into the understanding of the effects of aviation




22                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                    To obtain more precise ground based UV measure-



                                                                                        Figure 4. Comparison between
                                                                                        modelled and observed ozone above
                                                                                        Andøya on 26 March 1996. The red
                                                                                        curve shows the simulated ozone
                                                                                        field assuming that ozone is advect-
                                                                                        ed as an inert tracer, the green curve
                                                                                        shows simulated ozone taking into
                                                                                        account all known chemical proc-
                                                                                        esses, and the blue curve represents
                                                                                        measurement of the ozone profile
                                                                                        with the ALOMAR ozone lidar.
                                                                                        Adapted from Hansen et al., 1997.




in the climatic sensitive region, the upper troposphere and the lower stratosphere. Future projections
of air traffic show a substantial increase, and it is important to get better estimates of the impact on the
chemistry in this region from the air fleet emissions.
The rapid increase in the use of some of the CFC substitutes (see Figure 5) could lead to a delay in
the expected decline in atmospheric chlorine. It will therefore be of importance to carry out model
runs for different chlorine and bromine scenarios.
Decreasing temperatures in the stratosphere due to an increase in greenhouse gases and due to a de-
cline in stratospheric ozone represents a serious risk for future major ozone loss in the Arctic vortex.
It will therefore be important to carry out model runs for various temperature scenarios.

5.5 To obtain more precise ground based UV measurements
Global UV measurements are performed at many sites with different instruments. To derive UV
trends, comparison between different measurements have to be done, e.g. between high quality spec-
tral UV measurements and filter radiometric data. Within this project, methods to correct for different
instrumental properties, as for instance different cosine response, will be investigated. It will be an
important goal to evaluate the accuracy of these methods during variable cloud conditions. These cor-
rection methods need input from additional UV measurements such as direct and diffuse UV radiation
during all weather conditions, but also improved knowledge about radiance distribution. The estab-

                                                                                       Figure 5. The annual emissions
                                Emissions according to AFEAS
                                                                                       (ktons) of some of the replacement
             40.0
                                                                                       compounds according to AFEAS
                                                                                       (1997). This shows the rapid in-
             35.0
                                                                                       crease in the use of HCFC-141b
             30.0
                                                                                       and HCFC-134a.
             25.0                                                          HCFC-142b
                                                                           HCFC-141b
     ktons




             20.0
                                                                           HFC-134a
             15.0

             10.0

              5.0

              0.0
                1980   1982   1984   1986      1988   1990   1992   1994

                                            Year




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                        23
Chapter 5: Scientific objectives

lishment of equipment and methods to produce high quality data for this purpose will be an important
part of this project. Knowledge about the UV radiance distribution will give information about atmos-
pheric processes and how these influence UV doses at the ground. Measured UV irradiances will be
compared with available models.

5.6 To study the effect of clouds on surface UV radiation
The main objective of this task is to use existing UV measurements together with an existing radiative
transfer model to investigate the influence of clouds on UV radiation at selected sites in Norway.

5.7 To measure the altitude variations of the UV radiation field
The main objective of this task is to measure the UV radiation field in the troposphere and the lower
stratosphere to gain new knowledge about the UV radiation field. Specifically the plausible correlation
between the ozone profile and the UV radiation profile will be investigated. It is also planned to quan-
tify the effect of other parameters, such as the surface albedo and tropospheric clouds, on the UV ra-
diation profile.

5.8 UV scenarios
The main objective is to develop present and future UV maps for Norway with know errors. The maps
are aimed at biologists and physicians whose input will be consulted when generating the maps.




24                                    Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                         3-D modelling of atmospheric chemistry


CHAPTER 6:                       Tasks and Methods
Task 1: 3-D modelling of atmospheric chemistry
Task leader: Ivar Isaksen, UiO
Major Objectives:
            • Further development and application of a 3-D CTM to study ozone depletion processes
              in the polar stratosphere
            • Perform comparisons with observations to quantify ozone depletion
            • Study the interaction between climate (temperature) changes and stratospheric ozone
              changes
            • Perform long-term (several years) 3-D CTM studies of ozone layer changes
Relation to phase 1:
In Task 1 we will use the same models as in phase 1 of COZUV, namely the Oslo CTM2 and SCTM-
1 models. The models will, to a limited extent, be further developed, and they will be applied for new
studies.
The CTM2 will be extended upward to 0.1 hPa, to allow studies of the upper stratosphere and to im-
prove the circulation of the lower stratosphere and reduce the impact of the upper boundary condition
on the lower stratosphere (Activity 1.1). The routines for provision of meteorological data will be up-
dated accordingly (Activity 1.5). A faster scheme for calculations of dissociation rates will be imple-
mented in SCTM-1, to allow longer integrations (Activity 1.3).
Evaluation of the models in phase 1 revealed shortcomings in the parameterisation of the microphys-
ics of aerosols and PSCs and the heterogeneous chemistry, leading to an underestimation of the chlo-
rine activation. This will be sought improved in phase 2, with main emphasis on the NAT particles
(Activities 1.1 and 1.3).
The SCTM-1 model will, after refinements, be used to calculate improved long-term trends of ozone,
both in the past (to be compared to observations in Task 6) and the future (Activity 1.2). The CTM-2
model will be used for process studies, as in phase 1, with emphasis of impacts of model improve-
ments. The winter 1999-2000 will be studied in particular since this was a very cold winter with ex-
tensive ozone depletion in the Arctic. Furthermore we will focus on the spring and summer seasons
in addition to the winter season, which was studied in phase 1 (Activity 1.1 and 1.4). In the analysis
of the model results, changes in temperatures and transport winds will be a focus in phase 2, in addi-
tion to the chemistry, which was mainly emphasized in phase 1 (Activity 1.4).
A new application in phase 2 will be studies of the upper stratosphere, with a main emphasis on water
vapor and the impact on ozone (Activity 1.2).
Coupling to other parts of the project:
            There will be collaboration with the observational groups on ozone processes and long-
            term ozone loss studies.
            There is a link to Task 2 where SLIMCAT, an isentropic model, will be used to look at
            transport processes. This will augment the chemical modelling and help interpret the re-
            sults.
            There are links to Tasks 3 and 4, where model results will be compared with observed


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                              25
Chapter 6: Tasks and Methods

            ozone (and other trace gases as NO2 etc.) during past campaigns (SESAME, (THESEO
            and SOLVE) where a large set of observations are available (this might also be connected
            to Task 2, where UARS data will be available).
            There will be a link to Task 6 where the comparisons between modelled and observed
            ozone and other trace gases will be carried out.
            There are links to EU projects such as SOLICE, TRADEOFF, GOA and SOGE
Introduction
The modelling activities will mainly be performed at the Department of Geophysics, University of
Oslo, and will be led by Prof. Ivar S.A. Isaksen. This will be done in close collaboration with Prof.
Frode Stordal. Dr. Jostein Sundet, Michael Gauss and Bjørg Rognerud will also participate in the ac-
tivities.
Michael Gauss is working on a PhD through the current COZUV project (supervised by Professor Ivar
S.A. Isaksen), and has funding until March 31, 2002.
The modelling work will be a continuation of the ongoing work and a further application to study
ozone depletion processes. Particular emphasis will be placed on comparisons with extensive meas-
urements obtained during the project, and other observations obtained through collaborative EU
projects. This will enable us to evaluate the model performance and give a better estimate of the ozone
depletion through different loss processes.
The main purposes of the modelling activity are:
  • A. apply the newly developed CTM (Oslo CTM2) to interpret observations performed during the project, and
       to improve our understanding of chemical processes responsible for ozone loss at high and mid-latitudes
  • B. perform long-term ozone perturbation studies for the next 1 to 2 decades.
Modelling tools
The tools for these studies will be two global 3-D CTMs which have already been developed and used
for ozone studies, but need improvements to meet the objectives of this proposal. The models will
have different temporal and spatial resolutions, but will have the same stratospheric chemistry pack-
age. One model, the Oslo CTM2, will be used for process studies. The other one, Oslo SCTM-1, will
be used for long-term runs.

Oslo CTM2
Oslo CTM2 (Sundet, 1997) uses wind velocity, sub-grid processes, temperature, humidity and surface
pressure data that has been extracted from the ECMWF model. The model is a new version of the glo-
bal 3-D model developed at the University of Oslo, Oslo CTM1 (Berntsen and Isaksen, 1997). The
initial data from ECMWF is extracted on a resolution corresponding to T63, and the CTM can be run
on either T21, T42 or T63 resolution, corresponding to horizontal resolutions of 5.6˚, 2.8˚ and 1.9˚, re-
spectively. The CTM is set up with the same vertical resolution as the (optional) 19 layers version of
the ECMWF model with approximately five layers in the stratosphere. The top level of the model is
at 10hPa. The model has the same chemical scheme as the Oslo CTM1 model, which is basically a
tropospheric scheme. The CTM1, which is a coarse resolution model with 9 vertical layers, has been
run for several years with the full diurnal chemistry, reproducing global distributions of ozone NOx
and CO that are in agreement with observations of the latitudinal, longitudinal and seasonal distribu-
tions in the lower troposphere. This model has been thoroughly tested, and has participated in the
IGAC/GIM 3-D model intercomparison. It has also been extensively used in the recent IPCC assess-
ment on aircraft impact (IPCC, 1999). To look at processes in the lower stratosphere, a stratospheric
chemical scheme was successfully included during the ongoing COZUV project. The chemical


26                                        Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                                  3-D modelling of atmospheric chemistry


scheme used to estimate the stratospheric species included in Oslo CTM2 is the same that is used in
the well tested Oslo stratospheric 2-D model (Stordal et al., 1985). The 2-D stratospheric model has
been used in several WMO ozone assessments and the model results are reasonable compared to other
models. This well documented scheme has also been used in the Oslo SCTM-1 for several years
(Rummukainen, 1996; Rummukainen et al., 1999). Oslo CTM2 will be used for process studies. Fig-
ures 6 and 7 show comparisons between modelled and measured ozone.




 200                          250       300    350           400        450       500   200        250       300           350   400   450   500

 Figure 6. Total ozone as observed by GOME (upper panel) and as modelled by CTM-2 (lower panel) on 15 February
 1996, [Dobson Units]. (Note: The blue area east of the Caspian Sea (upper panel) indicates an area where no data was
 available.)




                                        Vertical ozone profile over AND∅YA, [molec/cm3]

                     30

                              OSLO 2D


                     25




                     20
                                                         NASA
       Height [km]




                                                         11MAR96
                                                         23:56GMT
                     15


                                                                                   CTM2
                              tropopause
                                                                                   12MAR96
                     10                                                            00:00GMT




                      5




                      0
                          0                1         2              3         4               5          6
                                                                                                                      12
                                                                                                                   x 10

  Figure 7. Comparison of a modelled (solid black curve) and a measured (dashed curve) ozone profile for around
  midnight on 12 March 1996. The measured curve is from the ALOMAR ozone lidar located at Andøya.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                                         27
Chapter 6: Tasks and Methods

Oslo SCTM-1
The Oslo SCTM-1 is originally a 21-layer model covering the height region from the surface up to
0.0022hPa (Rummukainen et al, 1999). The model has recently been extended with 8 extra layers in
the lower stratosphere and upper troposphere. The temperature data are NCEP analyses with one tem-
perature file for each date of the year. The transport data is generated by a GCM. The concentrations
of the different species were originally initiated with data from the Oslo 2-D stratospheric model, but
the model has been run for three years as a spin up time and can therefore now be initiated with 3-D
data. The 3-D CTM has been run for several years with the full diurnal chemistry, reproducing an
ozone distribution that is in good agreement with observations of the latitudinal, longitudinal and sea-
sonal distribution of ozone column densities. It also gives a good representation of the ozone distribu-
tion in the stratosphere (Rummukainen et al., 1999). The model participated in the IPCC assessment
of atmospheric impact from aircraft emissions (IPCC, 1999), where it was used to study potential im-
pact of a future fleet of supersonic aircraft (in 2015). This model will be used for long-term runs.


Activity 1.1: Further development of a global 3-D CTM for stratospheric process
              studies.
Responsible scientists:       Dr. student Michael Gauss supervised by Ivar Isaksen and Jostein
                              Sundet
The model development and the study will be based on the most recent version of the OSLO CTM2
(see above). The Oslo CTM2 model will be used to perform ozone process studies. The model com-
bines tropospheric and stratospheric chemistry, but has still problems to simulate the full extent of ClO
activation due to heterogeneous chemistry during early spring at high latitudes. To remedy this the het-
erogeneous chemistry module used in CTM2 will be further improved. This will be done in close col-
laboration with activity 1.3 where heterogeneous chemistry will be improved in the stratospheric
model SCTM-1.
As a major modification of the model domain, the vertical extent of CTM2 will be enlarged up to the
0.1hPa level as soon as meteorological data for the stratosphere and the lower mesosphere are made
available by ECMWF (anticipated for the end of 2000). This will lead to a much better representation
of the stratospheric transport processes in CTM2. Also, the chemistry scheme will then be applied in
the whole stratosphere.
Process studies performed with Oslo CTM2, will form the basis for the long-term runs that will be
performed with Oslo SCTM-1. As the ozone loss processes differ from year to year, several long-term
runs are needed.
During the current COZUV project Michael Gauss has already been working with the further devel-
opment of CTM2 which will form the basis for his Ph.D. thesis. The defence of the Ph.D. thesis is
scheduled for March 2002. For the remaining period within the time frame of this project we apply
for a post.doc. position for Michael Gauss.


Activity 1.2: Long-term studies of stratospheric ozone depletion.
Responsible scientist: Bjørg Rognerud
Ozone in the stratosphere is affected by both natural processes, such as the 11-year solar cycle, and
anthropogenic perturbations. Model studies will be performed to show how chemical processes in the
lower stratosphere are affected by changes in emissions of ozone reducing substances as well as the
solar variability. Effects connected to the solar cycle contribute to the natural perturbations and have
to be carefully investigated when comparing with the anthropogenic impact. We will study the past


28                                     Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                          3-D modelling of atmospheric chemistry


(last 20 years) as well as the future (adopting emission scenarios from WMO, 1998).
Another objective in this activity will be to look at processes in the upper stratosphere. The strat-
ospheric chemistry in the model is calculated up to about 58 km. To look at water vapour in the upper
stratosphere/lower mesosphere the chemistry has to be calculated up to 70 km. A simplified mes-
ospheric chemistry package has to be included in SCTM-1 in order to perform these studies.


Activity 1.3: Improvements of the stratospheric chemical transport model
Responsible scientist: Bjørg Rognerud
Improvements of the chemical schemes
Our stratospheric models (2-D and 3-D) used to predict ozone perturbations, have extensive chemical
schemes, which include oxygen, hydrogen, nitrogen, chlorine and bromine families, methane and its
oxidation products, approximately 50 chemical compounds. The models have a large number of chlo-
rine and bromine species and N2O as source gases. The heterogeneous aerosol/PSC chemistry in-
cludes hydrolysis of ClONO2, N2O5, and BrONO2, and reactions of ClONO2, HOCl and HOBr with
HCl. The scheme is specially designed to study ozone perturbations and effects caused by man-made
emissions (CFCs, bromine compounds, NOx from aircraft) (Isaksen and Stordal, 1986; Isaksen et al.,
1990; WMO, 1995). The scheme can also be used to study variations in the solar output (Zerefos et
al., 1997). It calculates the diurnal distribution (10 minutes time steps) of a large number of chemical
active compounds in the oxygen, nitrogen, chlorine and bromine families as well as the distribution
of more long lived compounds like CFCs and other chlorine containing source gases, bromine con-
taining source gases as well as N2O and CH4.
As part of COZUV the microphysical module by Carslaw et al (1995) was implemented in SCTM-1
and CTM2. This module gives a good representation of the liquid aerosols and the SAT particles, but
not the NAT particles as the module does not calculate the surface area of the NAT particles. Another
simplified microphysical model, which also calculates the surface area of NAT particles, will be im-
plemented in the models.
Calculation of photo-dissociation rates
SCTM-1 uses a radiative scheme for calculations of photo dissociation rates in the stratosphere and
the troposphere developed by Kylling et al. (1995). The calculations are performed interactively since
the photo dissociation rates depend on the overlying ozone column, and therefore will change with
changing ozone column. This is of particular importance for the long-term calculations since there is
a substantial self healing of ozone in the lower stratosphere when ozone is depleted in the upper strat-
osphere. Since long-term 3-D ozone perturbation studies are very time consuming it is important to
make the calculation of photo dissociation rates effective. Michael Prather, University of California,
Irvine has developed a fast and accurate scheme called “fast-J”, to calculate the rates (Wild et al.,
2000). The stratospheric version of “fast-J” was implemented in CTM2 during the ongoing COZUV
project. Comparisons with the more extensive scheme used previously, show that the scheme is effi-
cient and accurate both in the troposphere and in the stratosphere. During the next period the “fast-J”
scheme will be implemented in SCTM-1.


Activity 1.4: Model studies of ozone loss processes
Responsible scientist: Michael Gauss
Process studies
This will include the studies of the distribution and changes in the distribution of ozone and chemical



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                               29
Chapter 6: Tasks and Methods

active compounds (NO2, OClO, BrO) involved in the ozone loss process, and estimates of ozone loss.
Such studies will typically cover a season. The studies will cover both the Arctic and mid-latitude re-
gions and there will be close interaction with the measurement studies.
The Oslo CTM2 model will be used to perform process studies regarding the chemistry of ozone. The
studies will focus on estimates of the ozone loss process under different atmospheric conditions and
how the loss changes with variations in the distribution of ozone and other chemically active species
involved in the ozone loss chemistry.
As the transport formulation in CTM2 is rather accurate and both tropospheric and stratospheric
chemistry are included, the model can be readily used to investigate both chemical and transport proc-
esses in the tropopause region. In particular, one will study how temperature and alterations in the
transport of chemical compounds affect the distribution and loss of ozone. These studies will focus
on variations and changes on time scales of days to a few months.
During phase 1 of COZUV we focused on the winter of 1995-96. In the second phase of COZUV the
study years will be 1997, 2000 and 2001.


Activity 1.5: Provision of meteorological data
Responsible scientist: Bojan Bojkov
NILU will, through a service set up by the Norwegian Meteorological Institute, transfer meteorolog-
ical data at T106 resolution from the European Centre for Medium Range Weather Forecasts (EC-
MWF). There will be global data for all the 60 model levels four times per day. At NILU there already
exists some software and routines for extraction and interpolation of these data, but there will be a
need for maintenance and further development of these. This will be of special importance when EC-
MWF extends the number of levels in their data. This means that many of the existing programs will
have to be updated or rewritten. There is also a need for daily surveillance of the data flow in order to
ensure that the data base is up to date.




30                                     Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                   Dynamical studies


Task 2: Dynamical studies
Task leader: Yvan Orsolini, NILU
Major objectives:
            • Examine the ability of transport models to reproduce realistically ozone structures
              seen in lidar observations, esp. in winter and spring during the THESEO and following
              campaigns.
            • Better understand the northern hemisphere high latitude ozone budget in the spring
              and summer, i.e. after the breakdown of the polar vortex, and the ozone chemistry oc-
              curring in the vortex debris during the transition to summer regime.
Relation to phase 1:
There will be continued comparison between modelled ozone and lidar observations at Andøya, but
with more focus on the spring/summer seasons.
The domain-filling Lagrangian chemical model developed and used in a case study in COZUV-I (see
progress report), will be used in new simulations of spring/summer 2000.
Coupling to other parts of the project:
            There are links with:
            TASK 1: comparisons have been made during COZUV-I between the CTM results and the
            high resolution Lagrangian model. These will be pursued in COZUV-2.
            TASK 3: Ozonesonde data will be used in the study of mini-holes.
            TASK 5: extensive comparisons with Lidar data and Lagrangian model.
            TASK 6: ozone loss estimates are derived from observations, and from both modelling ap-
            proaches (CTM and Lagrangian).


Activity 2.1: Ozone transport and chemistry in spring and summer
Responsible scientists: Yvan Orsolini, Georg Hansen, Inga Fløisand
There are still discrepancies between model prediction and observations of the year-round strat-
ospheric ozone decline in mid and high latitudes. In summer, current models still severely overesti-
mate ozone in the polar regions, and this appears as a major deficiency in our ability to model the
complete ozone seasonal cycle. We aim at improving our understanding and modelling of ozone loss
processes throughout winter/spring and also summer, in the northern mid and high latitudes.
Large-scale international ozone campaigns were staged out of Scandinavia in the late 1990s (THE-
SEO, THESEO 2000/EUROSOLVE). We intend to carry out several studies to exploit the results from
these campaigns.
Pursuing our past work (Orsolini et al., 2000), we will make use of the ALOMAR ozone lidar data,
to carry out detailed model/observations intercomparison. In particular, we plan to use new daylight
lidar observations to be made in the spring and summer 2000. We will attempt at re-constructing the
ozone profile and column observed at Andøya, including ozone layering and day-to-day variability,
by calculating a large amount of trajectories initialised with satellite observations (Orsolini et al.,
2000). In a broader context, satellite observations will also be used to characterise ozone transport in
this period. Lagrangian models will be used to investigate the interaction of chemistry and mixing in
the spring and summer stratosphere. These models will be used to diagnose the ozone loss mecha-


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                31
Chapter 6: Tasks and Methods




                                                                              Figure 8. Time-evolu-
                                                                              tion of re-constructed,
                                                                              model ozone partial pres-
                                                                              sure over the winter/
                                                                              spring 1997/98 at ALO-
                                                                              MAR. Short-lived lami-
                                                                              nations are ubiquitous,
                                                                              esp. below the ozone
                                                                              maximum, but they are
                                                                              most prominent during
                                                                              the final warming and
                                                                              break-up of the polar vor-
                                                                              tex in spring.




nisms and the overall fate of vortex debris in spring and during the transition into the summer circu-
lation. An example of modelled ozone is shown in Figure 8.


Activity 2.2: Ozone mini-hole events
Responsible scientist: Yvan Orsolini
Column ozone over Oslo during the THESEO2000 period was the lowest value ever measured in the
northern hemisphere around December 1, 1999. It hence occurred during a major ozone “mini-hole”
event, well before significant ozone destruction in the stratospheric polar vortex. While the cause of
such mini-hole is reasonably understood (Orsolini et al., 1995, 1998), this event was characterised by
very cold lower stratospheric temperatures that might have caused PSC formation. We will carry out
an observational study of such events, and examine their interannual variability using satellite and
ground-based data.




32                                    Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                            Ozonesonde observations


Task 3: Ozonesonde observations
Task leader: Geir O. Braathen
Major Objectives:
            • To continue the long-term records of ozonesonde observations obtained from Norwe-
              gian stations since the late 1980s and early 1990s in order to build and maintain a ver-
              tically resolved ozone climatology for Norway and the Norwegian part of the Arctic
            • To contribute to international campaigns and programs where the Norwegian stations
              participate
            • To provide other experimentalists with auxiliary data needed for comparison, valida-
              tion and calculation of air mass factors
            • To provide ozone profile data needed for model validation
            • To provide data for the assessment of chemically-induced ozone loss
Relation to phase 1:
Since task 3 is an observational task that serves several other tasks, it will be very similar to task 3 in
COZUV-1. The observation program from COZUV-1 (Act. 3.1) will be continued unchanged. There
are also new Match campaigns under way, at least for the winter of 2000-01 where NILU wants to
participate.
Coupling to other parts of the project:
            Data from the ozonesonde observations will be used by several other COZUV tasks:
            Task 2 will use ozonesonde data in the study of mini-holes.
            Task 4 will need ozonesonde profiles for verification of total ozone values and for calcu-
            lation of so-called air mass factors, which are used to convert slant column measurements
            to vertical columns.
            Task 5 will need ozonesonde profiles for direct comparison between ozone profiles meas-
            ured with sondes and with the ALOMAR ozone lidar.
            Task 6 will need ozonesonde data for analysis of chemically-induced ozone loss.
            Task 9 will need ozone profile information for the model calculation of UV doses at the
            ground.
            Input to Task 3 will come from Tasks 4 and 5 for verification of the sonde observations.


Activity 3.1: Climatological measurements
Responsible scientist: Bojan Bojkov
NILU proposes to launch ozonesondes from one Norwegian stations, namely Kjeller (NILU head-
quarters). Ozonesondes have been launched regularly from nearby Gardermoen since November
1990. This site participated in the EASOE and SESAME campaigns as well as in the OSDOC project.
Ozonesonde data play an important role in the assessment of ozone loss, especially inside the polar
vortex. Ozonesondes can be launched under virtually any weather conditions, and they can take meas-
urements also during the polar night. Data from these sites will therefore constitute a continuous
record of observations throughout the winters and will be used to assess the degree of chemically-in-



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                   33
Chapter 6: Tasks and Methods


              35                                                        35


              30                                                        30


              25                                                        25
Høyde (km)




                                                           Høyde (km)
              20                                                        20
Height (km)




              15                                                        15


              10                      1997                              10                        1997
                                      1996                                                        1996
                                      1995                                                        1995
                                      1994                                                        1994
               5                      1993                               5                        1993
                                      1992                                                        1992

               0                                                         0
                0   4          8        12       16   20                  0   4             8       12       16   20
                      Partialtrykk pressure (mPa)
                     Ozone partial av ozon (mPa)                                   Partialtrykk pressure (mPa)
                                                                                  Ozone partialav ozon (mPa)

 Figure 9. Mean ozone profiles from Gardermoen (left) and Bjørnøya (right) for the time period January to June for
 the years from 1992 through 1997.



duced ozone loss. It is also important to continue the record of observations that has been collected so
far. Figure 9 shows averaged ozonesonde profiles for the first six months of the year based on sondes
launched from Gardermoen and Bjørnøya (Bear Island) for the years 1992-1997. In order to continue
the long-term record it is recommended to launch at least one sonde per week around the year. We
therefore apply for approx. 100 kNOK per year to complement the funding from the State Pollution
Control Authority, which is not sufficient to maintain a continuous ozonesonde record.


Activity 3.2: Participation in international ozonesonde programmes
Responsible scientist: Bojan Bojkov
In the current project these two stations form a part of a larger network of European, Canadian and
Japanese stations as shown in Figure 10. This network has been built up in conjunction with the Eu-
ropean ozone campaigns EASOE and SESAME and was also in operation during THESEO. The par-
ticipants in this project will benefit from the availability of data from this network. For example, data
from the German ozonesonde station in Ny-Ålesund will be used in the analysis of data from the
SAOZ spectrometer, which is operated by NILU (see task 4). On the other hand, the Norwegian data
will constitute an important contribution to the network. During international campaigns the launch
frequency will be increased to 2-3 launches per week, depending on the meteorological situation.




34                                             Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                        Ozonesonde observations



                                                                                                 Figure 10.
                                                                                                 This map shows
                                                                                                 the complete net-
                                                                                   TS
                                                                                                 work of stations
                                                                              MS
                                                                                                 participating in
                                                                                                 the European
                                                                                                 ozonesonde/lidar
                                                                                                 activities. The red
                                                                                                 dots indicate
                                                                             YA                  ozonesonde sta-
                ED
        BO                                                                                       tions, and the
                                                                                                 green dots are
                                                                                                 lidar stations.
                        RS
                CH
                                  EU
                                                                                                 Some stations
                                       AL                                                        have both sonde
                         TH
           TO                                                                                    and a lidar facili-
                                             NA                                                  ties.
      WI
                        SS                             BI
                GB                     SC
                                                  AN         SO
                                                        KI
                             RE               OR
                                                               JO            MO
                                        LE           GA
                                                   JA
                                        AB DB      KU LI           LN
                                  VA
                                                              PR
                                             UC
                                                            HO
                                              PA
                                                             CA         TL
                                        MA        HP         AQ              AT



                        TE




                                                       Launch of an ozonesonde from Gardermoen
                                                       Photo: Victor Dahl.
                                                       Photo manipulation: Finn Bjørklid.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                              35
Chapter 6: Tasks and Methods


Task 4: DOAS measurements
Task leader: Bill Arlander, NILU
Major objectives:
            • To characterise long-term ozone loss trends as part of a global measurement network.
            • To characterise airmass composition during transport to mid-latitudes
            • To validate and optimise chemical transport models (CTMs).
            • To validate and calibrate satellite borne instrumentation, both present and in the fu-
              ture. i.e., GOME on ERS-2, and SCIAMACHY on ENVISAT
Relation to phase 1:
Task 4 has two aspects:
1) To carry out long term monitoring of ozone and other important stratospheric constituents.
2) To improve the DOAS technique for difficult molecules, such as NO2, OClO and BrO.
For the first aspect phase two of COZUV will be similar to the first phase with daily observations as
long as there is enough light. For the second aspect we plan to further develop the DOAS technique
so that the measurements of difficult molecules become more accurate. There will also be an attempt
to observe the elusive molecule IO.
Coupling to other parts of the project:
            There are couplings to Tasks 1 and 6 for the geophysical interpretation and comparison
            of measured and modelled chemical compounds at Ny-Ålesund and Andøya.
            There is a link to Task 3 for evaluation and comparison of ozone total columns at Ny-
            Ålesund and Andøya.
            There is a link to Task 5 for direct comparisons of total column ozone at Andøya.
In the continuation of efforts from the initial COZUV project as well as in several EU funded projects,
NILU is planning further UV/Vis DOAS monitoring activities at Ny-Ålesund (78.9˚N, 11.9˚E) for to-
tal column O3 and NO2 and at Andøya (69.3˚N, 16.0˚E) for total column O3 and NO2 and slant column
BrO and OClO. The measurement record from Ny-Ålesund and Andøya began in 1990 and 1998, re-
spectively. These systems have been actively involved in numerous EU and nationally funded projects
aimed at the elucidation of processes that lead to stratospheric ozone depletion at high latitudes. In
recent years, NILU has also used these instruments within satellite validation projects. Due to the
viewing geometry, satellite instrumentation typically has great difficulty measuring the above-men-
tioned compounds at high latitudes. The NILU DOAS systems located in Ny-Ålesund and Andøya
therefore play an important validation role, in particular for the GOME spectrometer on ERS-2, and
later for the SCIAMACHY, MIPAS and GOMOS spectrometers on the ENVISAT platform to be
launched in June 2001.
In order to address the major objectives listed above, NILU proposes the following activities:
1) Improvement in the airmass factor (AMF) calculations for NO2 and O3. Considerable work has
been done for ozone, so the main emphasis in this project will be put on developing seasonally aver-
aged AMFs for NO2. As for ozone, NO2 exhibits significant latitudinal and seasonal variations that
need to be accounted for in the AMF calculations (Høiskar et al., 1999).
2) As was the case for NO2 and O3 the development in the determination of AMFs for BrO and OClO,
needed for the conversion of slant to vertical column density, depends on accurate knowledge of their


36                                     Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                                                   DOAS measurements



                                                            Andoya, 69° N
                              3.5
                                                                                                                  Figure 11. A compari-
                                          Meas. AM
                                                                                                                  son between modelled and
                                          Meas. PM
                               3          Model AM                                                                observed differential slant
    molec/cm ]
    2




                                          Model PM                                                                column densities of BrO at
                                                                                                                  90˚ SZA (am and pm) from
                              2.5                                                                                 July 1998 to August 1999 at
                                                                                                                  Andøya. The SLIMCAT
    14




                                                                                                                  model results come from the
    BrO DSCD (90 − 80 ) [10




                               2                                                                                  University of Leeds.
   °




                              1.5
   °




                               1


                              0.5

                                    JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB MAR APR MAY
                               0
                                                                 1998 / 99


atmospheric profiles. A major challenge thus far has been the determination of the vertical profile dis-
tributions of these halogen species. In the case of BrO, the tropospheric contribution will also need to
be accounted for. Measured profiles available in the literature combined with the NILU box model
(Fløisand, 1999) and radiative transfer modelling present in the COZUV project will be used for the
calculation of the AMFs.
3) For the UV DOAS measurements from Andøya, the determination of background year-round
OClO (a key species in the coupling of the Br and Cl chemical families, and is a qualitative tracer of
activated chlorine chemistry within the winter polar vortex) will be attempted. In addition, attempts
will be made for the determination of IO in the visible region. The determination of IO in the lower
stratosphere was reported by Solomon, et al.(1994). Although IO is a highly reactive compound, it is
present in very low amounts and its ozone destruction potential is still to be determined.




                                                                                                          The SAOZ instrument (in the centre
                                                                                                          of the photograph) deployed on the
                                                                                                          observation platform of the research
                                                                                                          station of the Norwegian Polar insti-
                                                                                                          tute in Ny-Ålesund. In the foreground
                                                                                                          to the left the GUV-541 filter UV in-
                                                                                                          strument.
                                                                                                          Photo: Ove Hermansen




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                                       37
Chapter 6: Tasks and Methods


Task 5: Ozone lidar measurements
Task leader: Ulf-Peter Hoppe, FFI, with assistance from Georg Hansen, NILU
Major objectives:
            • To measure ozone vertical profiles with a high spatial and temporal resolution through-
              out the duration of the project
            • To provide information on other atmospheric parameters relevant for ozone: polar
              stratospheric clouds, temperature profile, air density profile
            • To provide experimental evidence used in the modelling of exchange of air masses be-
              tween the polar vortex and mid-latitudes
Relation to phase 1:
Task 5 in this application is a direct continuation of the corresponding task in the previous phase. The
following improvements have been made: The data analysis has been evaluated, validated, and the
analysis job has been made more user-friendly and therefore quicker. The instrument has been im-
proved to make it easier to align laser beam and telescope field of view, leading to more reliable results
of the temperature profiles. (The ozone profiles were not impeded before, either.) Until the next polar
summer, the daylight capabilities will be significantly enhanced. This will lead to more ozone profiles,
and of a better quality, during daylight.
Coupling to other parts of the project:
            Results from tasks 2, 3, and 4 will be used to optimise height resolution versus time reso-
            lution and to decide during which periods observations should be done with the highest
            priority.
            Data from task 5 will be used in task 6 for the calculation of chemically-induced ozone
            depletion.
The ozone DIAL system at Andøya is operated jointly by the Norwegian Defence Research Establish-
ment (FFI), NILU and the Andøya Rocket Range. With this instrument one can obtain vertical ozone
profiles from about 10 to 45 km at solar depression angles of more than 2 degrees. The altitude reso-
lution is about 300 m below 25 km altitude and 1000 m above, the time resolution about 1 hour, under
favourable conditions even less (about 30 min.). Figure 12 shows an overview over the ozone layer as
measured with the lidar in winter 98/99. It reveals a major stratospheric warming already in mid-De-
cember 1998, and the final warming with strong filamentation occurring in early March 1999.
The system is now technically upgraded in order to allow measurements during daylight, but routine
operation in this mode has not been achieved yet. As soon as it is, year-around measurement capability
will be possible and the instrument will be less sensitive to natural conditions such as sky brightness
and weather. Figure 13 shows an ozone profile measured with a solar elevation angle of 34˚. It is also
intended to upgrade the system with a tropospheric receiver in the near future. This will improve the
ability to derive total ozone from the lidar profiles (besides ozonesondes the only way to derive total
ozone in mid-winter at this latitude), yield observational evidence on stratosphere-troposphere ex-
change (STE) processes, and make the system less vulnerable to aerosol load, e.g., after volcanic erup-
tions or in presence of polar stratospheric clouds and cirrus.
Data from the lidar will be used both to obtain an ozone climatology and for high-resolution studies,
both in time and altitude, of filaments (Orsolini et al., 1997, 2000) and for verification of model-de-
rived chemical ozone depletion (Hansen et al., 1997; Hansen and Chipperfield, 1999). Another focus
in the frame of this project will be on the investigation of the ozone layer after the vortex break-up and
during summer, where models so far have failed to reproduce the measured values.


38                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                       Ozone lidar measurements


                                                                                 Figure 12. Vertically
                                                                                 resolved ozone number
                                                                                 density [10-12 cm-3]
                                                                                 throughout winter 1998/
                                                                                 99 as measured with the
                                                                                 ALOMAR ozone lidar.
                                                                                 Occasions of measure-
                                                                                 ments are marked with
                                                                                 diamonds at the bottom
                                                                                 of the plot. The figure
                                                                                 shows the occurrence of
                                                                                 a major stratospheric
                                                                                 warming in mid-De-
                                                                                 cember 1998 with a
                                                                                 marked increase of the
                                                                                 ozone density through-
                                                                                 out the height range
                                                                                 monitored and a second
                                                                                 - the final - warming at
                                                                                 the end of February
                                                                                 causing strong lamina-
                                                                                 tion at the maximum of
                                                                                 the ozone layer and be-
                                                                                 low.

The ozone density values are derived from atmospheric backscatter profiles at two UV wavelengths
(308 and 353 nm). From these, also atmospheric temperature and density can be derived over a wide
altitude range (typically from 20 to 60 km, possibly also down to the upper troposphere). Moreover,
the backscatter profiles on both wavelengths yield valuable information on aerosol and cloud layers,
such as polar stratospheric clouds (PSC) and cirrus clouds (e.g. Hansen and Hoppe, 1997). The other
large lidar system at ALOMAR, the Rayleigh-Mie-Raman system, gives even more information about
these layers (3 wavelengths, measured aerosol-free reference profiles, temperature inside the aerosol
layers). Combining these two optical systems and the wind measurements at the same site (MST radar,
Doppler wind and temperature system, MF radar) results in one of the most complete data sets on
PSCs that is globally achievable with respect to these clouds which are of prime importance for ozone
destruction.


                                                                  Figure 13. Ozone lidar profile
                                                                  measured at ALOMAR with the
                                                                  new daylight system. This profile
                                                                  was measured on August 5, 1998
                                                                  in bright daylight when the solar
                                                                  elevation angle varied between 31
                                                                  and 35˚. This figures demonstrates
                                                                  the capability of ALOMAR to
                                                                  measure ozone profiles during
                                                                  daylight. This extends the meas-
                                                                  urement season to also include the
                                                                  summer when there is midnight
                                                                  sun.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                   39
Chapter 6: Tasks and Methods


Task 6: Analysis of ozone change
Task leader: Frode Stordal, NILU
Major objectives:
            • Assess the degree of chemical ozone loss and its geographical extent
            • Get a handle on the processes and parameters that control ozone concentrations over
              the course of the winter, such as temperature, water vapour, HNO3, halogens, aerosols,
              PSC incidence etc.
            • Compare model results with observations from the ground, from balloons and from sat-
              ellites
Relation to phase 1:
In phase 1 of COZUV the plan was to investigate winters 1998-99 and 1999-2000. Due to availability
of input data for the 3-D CTM it was decided to look at winter 1995-96 instead. This is described in
the progress report.
In phase 2 of COZUV we will now investigate the winter of 1999-2000, as originally planned. We
now know that this turned out to be a very cold winter with the largest local chemically-induced ozone
loss ever observed. It will therefore be of interest to study this winter in detail.
In activity 6.2 one will analyse the winters of 2000-01 and 2001-02 with the same method as applied
in COZUV-1 to earlier winters (1988-89 to 1999-2000). These earlier studies have been concentrated
on the 475K isentropic level. In COZUV-2 one will also look at other levels: 400, 450, 500 and 550K,
both for earlier winters and for the 00-01 and 01-02 winters.
A new study in Act. 6.3 is the calculation of long term (last 20 years) ozone change with the SCTM
and comparison with available long-term satellite data (SAGE I + II).
Coupling to other parts of the project:
            This task plays a central role in the project and requires input from several other tasks.
            Model results from Tasks 1 and 2, as well as observations from tasks 3 and 5 will be used
            in the comparison between modelled and observed ozone loss.
            There is also a links from Task 6 to Tasks 1 since the comparison feeds back to model de-
            velopment and testing.


Activity 6.1: Hemispheric data
Responsible scientist: Georg Hansen
In order to obtain a hemispheric overview of the ozone field and its temporal development during the
two winters of 2000-01 and 2001-02 we will collect satellite data in addition to the observations car-
ried out in COZUV.
The total ozone instruments expected to be operating in orbit at the time of the project are GOME on
board ERS-2 (ESA) and TOMS on board the Earth Probe (NASA). During the second half of the
project we expect to obtain data from the SCIAMACHY instrument on board ENVISAT. NILU par-
ticipates in several AO projects on ENVISAT validation and will therefore have early and direct access
to such data. Comparison between UV-visible ground-based spectrometers and GOME over a wide
range of latitudes and SZAs have been conducted during the validation phase of the satellite instru-
ment. (e.g., Hansen and Dahlback, 1996; Hansen et al., 1999). Comparison between SAOZ and


40                                     Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                            Analysis of ozone change


TOMS also shows a good agreement but limited to SZA < 80˚. The satellite data will therefore be ex-
tremely useful to extend the geographical coverage of the study, but not during the winter in the Arc-
tic.
Data from the Network for the Detection of Stratospheric Change (NDSC), which COSE is a part of,
will provide information on the same species on a global scale.
Ozonesonde data from the whole European, Canadian and Japanese networks will be used to get a
broader picture of the vertical distribution of the ozone variation.


Activity 6.2: Temporal development of the ozone mixing ratio on isentropic
              surfaces
Responsible scientist: Geir Braathen
In an idealised polar vortex the ozone mixing ratio at any given isentropic level is constant. In “real
life” there are three processes which can disturb this relationship: 1) Diabatic descent of air masses
due to radiative heat loss to space, 2) lateral mixing with air masses at middle latitudes due to leakage
through the vortex wall and 3) chemical depletion of ozone. The diabatic descent during the winter
will cause the ozone mixing ratio at a given isentropic level to increase since the mixing ratio increases
with altitude in the height region of interest for ozone destruction (14-25km). The degree of lateral
mixing can be limited by studying data taken deep inside the vortex. The third process, chemical de-
struction of ozone, is the one we want to quantify. By studying the ozone mixing ratio, measured with
ozonesondes launched from a large number of sites deep inside the vortex, as a function of time
throughout the winter one will get a conservative estimate of the chemical depletion of ozone.
This technique has been employed in several studies based on ozonesonde data collected in the Arctic
and Europe since 1988 (Kyrö et al.; 1992, Braathen, 1992; Braathen et al., 1994, 1995, 1996, 1998).
The ozone change is compared to the possible amount of polar stratospheric clouds, as estimated from
ECMWF temperature data. As an example the result of this analysis for the winters of 1991-92 and
1999-00 is shown in Figure 14. See figure legend for details.
In COZUV-2 the same analysis will be carried out. Earlier studies, including the one performed in
COZUV-1, have concentrated on the 475K level. In COZUV-2 the study will also include other levels:
400, 450, 500 and 550K. These additional levels will be studied both for earlier winters (1988-89 to
1999-00) and for the new winters (00-01 and 01-02).
Information on the degree of diabatic descent during the winter will be used. Such information has
already been used in two recent works (Braathen et al., 1999, 2000). Diabatic descent rates can be ob-
tained from several sources:
1) The 3-D model described in Task 1 contains a radiation module that calculates the diabatic descent
rates based on the ECMWF data. 2) The 3-D dynamical model described in Task 2 (Slimcat) also con-
tains a radiation code (Midrad) which produces diabatic cooling rates. 3) The diabatic cooling rate is
also a special product calculated at ECMWF. 4) These calculated descent rates will be checked against
descent rates obtained from measurements of inert tracers, such as N2O and CH4, obtained from bal-
loon experiments.


Activity 6.3: Comparison between modelled and observed ozone loss
Responsible scientist: Frode Stordal
Results from observations and modelling in other tasks will be compared to estimate the chemical



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                 41
Chapter 6: Tasks and Methods

ozone loss during individual winters and to establish a trend in ozone over the last 20 years. In phase
1 of COZUV, we have used results from several models and observations in a comparative study to
estimate the chemical loss during the winter 1996. Based on the same methodology we will in phase
2 of COZUV perform similar analyses for a selection of years, namely 1997, 2000 and 2001. The win-
ter 1999-2000 was a very cold winter with record high ozone loss around 20km. A large set of obser-
vational data is available for this winter due to the SOLVE and THESEO 2000 campaigns. We will
include in our analyses also results from the MATCH campaigns. In addition we will focus on chem-
ical changes in ozone during the spring and summer period, focusing on 2000. Finally, we will quan-
tify trends in stratospheric ozone over the last 20 years based on the Oslo SCTM and observations.
Special emphasis will be given to ozonesonde observations since the start of the European stratospher-
ic ozone campaigns in the early 1990s and to satellite data, in particular SAGE I and SAGE II. The
data will be analysed and used in terms of height resolved zonal means.




                                                                             4                                                                                                       4
                                   1991-92
                               8
                          7.5*10                                                                                                        8
                                                                                                                                   7.5*10
                                                                                 Ozone mixing ratio [ppm]




                                                                                                                                                                                         Ozone mixing ratio [ppm]
   Processed Area [km ]
  2




                                                                                                            Processed Area [km ]
                                                                                                            2




                                                                             3                                                                                                       3
                               8
                          5.0*10                                                                                                        8
                                                                                                                                   5.0*10



                                                                             2                                                                                                       2
                               8
                          2.5*10                                                                                                        8
                                                                                                                                   2.5*10



                               0
                                                                                                                                                  1999-00
                          0.0*10                                             1                                                          0
                                                                                                                                   0.0*10                                            1
                                   -25   0   25           50   75      100                                                                  -25     0   25           50   75   100
                                             Day number                                                                                                 Day number

             Figure 14. The ozone mixing ratio at the isentropic level of 475K (approx. 20km) as a function of time during
             the winter of 1991-92 (left) and 1999-2000 (right). The red dots represent measurements from individual ozone
             soundings. The orange curve is a gaussian 15 days running mean. The light blue shaded curve represents the pos-
             sible geographic area covered with polar stratospheric clouds based on ECMWF temperature data. It is clearly
             seen that the 1991-92 winter was relatively mild with PSC existence temperature only during late December and
             until 25 January. It is also seen that the ozone mixing ratio is nearly constant around 3ppm throughout the winter.
             In contrast, the winter 1999-00 had temperatures below the PSC condensation limit from early December and
             until mid March. The low temperatures and PSC activity led to a substantial ozone depletion where the mixing
             ratio dropped from approx. 3.5ppm to approx. 1.0ppm from mid December to late March. The sonde data used
             were all collected well inside the polar vortex. The ozone data in these figures have not been corrected for diabatic
             descent during the winter, which means that the ozone loss probably has been somewhat higher than deduced from
             these figures. When diabatic descent is taken into consideration the ozone loss for 1999-00 is 73%. Adapted from
             Braathen et al., 2000.



42                                                                  Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                 Ground based UV measurements


Task 7: Ground based UV measurements
Task leader: Berit Kjeldstad, NTNU
Major objectives:
            • UV radiance distribution in a sub-Arctic region, seasonal variations.
            • Impact of broken clouds on ground-based UV irradiance, measurements, analyses and
              validation
            • Measurements of global and direct UV in Trondheim as a part of a European network
              (EU funded project EDUCE).
            • Measurement and modelling of radiation on vertical surfaces
Relation to phase 1:
Task 7 will to a large extent represent a direct continuation of the work carried out in phase 1 of
COZUV. Activity 7.1 is a continuation of Act. 7.1 from phase 1, and the same is the case for Act. 7.2.
Act. 7.3 and 7.4 from COZUV-1 have been combined into the new Act. 7.3. Act. 7.4 in the second
phase of COZUV is entirely new and will be carried out by a new partner, namely Professor Arne
Dahlback of the Univ. of Oslo.
One of the milestones in COZUV-1 (Results on intercomparison of cosine error correction) was de-
layed and will therefore be completed in COZUV-2.
Coupling to other parts of the project:
            Results from Task 7.1 will be of importance for both Task 7.4 and Task 8 for validation of
            results. Results from 7.4 will be interesting for Task 9 where irradiance on vertical surfac-
            es as well as horizontal surfaces might be of interest for both biologists and physicists.


Activity 7.1: Direct and global UV measurements in Trondheim as part of a
              European network.
Responsible scientist: Berit Kjeldstad
Within the three year EU project European Database for Ultraviolet radiation Climatology and Eval-
uation (EDUCE) it is an overall goal to establish a UV climatology for Europe in combination with
investigations on potential long-term changes in ultraviolet radiation, caused by changes in ozone and
other factors affecting UV.
Trondheim will participate as one of 20 stations for these observations. Both direct and global UV ra-
diation will be measured and results will be given as input to the European database established within
the previous EU project SUVDAMA and continue with EDUCE. The data will also give useful back-
ground for campaign measurements to be performed in Tasks 1 and 2.
Objectives
Within the new project focus will be put on the need for ancillary measurements in addition to the
global irradiance measurements to develop new methods to evaluate the data and for interpretation of
the factors that determine the UV climatology.
Methods
A set of observations from the solar radiation platform in Trondheim will be used in this study (global
and direct spectral UV measurements, multichannel filter-radiometer measurements, global and direct
total radiation). Quality control and quality assurance of both UV irradiance measurements and the


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                43
Chapter 6: Tasks and Methods

ancillary data are strongly needed. The project will get technical assistance from NTNU.


Activity 7.2: UV radiance distribution in a sub-Arctic region
Responsible scientist: Trond Morten Thorseth
Radiance distributions of UV can be retrieved from radiative transfer models. There have been few
validations of these results with appropriate measurements (Grant et al.,1997; Blumthaler et al.,
1996).
Objective
In this study radiance distribution will be measured at different seasons on clear sky days. Differences
related to atmospheric constituents, such as ozone, will be investigated and compared with models.
Information on how radiance distribution changes with different atmospheric conditions will be of im-
portance for global UV irradiance measurements and correction of different angular response. Simu-
lated and measured effects of different angular response in UV instrumentation as a function of
changing radiation distribution will be tested (see Activity 7.2).
Methods
Within phase 1 of COZUV a new spectroradiometer, measuring direct and global irradiance has been
developed. With slight modifications and some technical developments the direct telescope on this in-
strument will be capable of performing radiance measurements.
The developed tracker system needs some further development to perform radiance measurements.
Tests performed in May 2000 will be used to validate the direct measurements. With a set of transmit-
ting diffusers that can be changed automatically within the telescope, radiance measurements can be
performed between global and direct measurements on a routine basis. New software implementation
will be needed as well as a new calibration procedure. A complete control of the programmable track-
er system with the diffuser change algorithm is needed for these automated measurements of radiance.


Activity 7.3: Impact of broken clouds on ground based UV irradiance; measure-
              ments, analyses and validation
Responsible scientist: Trond Morten Thorseth
Apart from solar elevation, clouds are the most important factor limiting the UV irradiance that
reaches the ground. The total impact of clouds on UV radiation has been studied from different points
of view in previous studies. Lately the effect of total cloud on long-term UV measurements (CIE-
weighted doses) has been quantified by Josefsson and Landelius (2000). Spectral measurements of
UV-B radiation under changing cloud cover is a great challenge. Scanning spectroradiometers with
photomultiplier detectors need from 3-7 minutes to complete a scan in the UV and correction for non-
ideal input optics becomes difficult due to the changing radiation distribution of UV. Thus, experi-
mental studies on cloud effects require special precautions. Modelling has shown a wavelength de-
pendent transmission (Seckmeyer et al., 1996; Erlick et al., 1998), which also has been observed
under heavy cloud conditions (Kylling et al., 1997). By combining spectral measurements with rapid
multichannel filterradiometer measurements, we will look at spectral effects of clouds during broken
cloud conditions.
Objectives
  • A. To perform spectral and moderate bandwidth measurements during broken cloud conditions, correcting for
       temporal effects during a scan.




44                                       Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                           Ground based UV measurements




                                            0.9                                                               10 0


                                            0.8
      Spectral Global Irradiance [W/m nm]


                                                                                                              10 -1
     2




                                            0.7
                                                                                                              10 -2
                                            0.6

                                                                                                              10 -3
                                            0.5

                                            0.4                                                               10 -4

                                            0.3
                                                                                                              10 -5
                                            0.2
                                                                                                              10 -6
                                            0.1

                                             0                                                               10 -7
                                             280   300   320     340       360             380             400
                                                           Wavelength [nm]
    Figure 15. Synthetic spectra (grey colour) retrieved from a combination of “slow scanning” spectroradiom-
    eter and a high frequency logging multi-filter radiometer. Spectra on a six orders of magnitude irradiance scale
    can be retrieved every second.



  • B. Investigate spectral effects of clouds for different cloud types and spatial distribution. Emphasis will be put
       on cases with broken cloud conditions.
  • C. Methods for cosine correction at broken cloud conditions will be studied with two different radiometers
       measuring simultaneously.
Methods
Work performed within COZUV phase 1 has demonstrated that it is possible to achieve spectral in-
formation under variable cloud conditions which is not affected by temporal cloud changes (Thorseth
and Kjeldstad, 1999). From a combination of spectral measurements and rapid filterradiometer meas-
urements, “instantaneous” spectra can be retrieved. In Figure 15 the green curve represent the real
measurements while the red and grey curves illustrate instantaneous spectra retrieved during this spe-
cific scan, which do not include any temporal effects of changing cloud cover. The red spectra repre-
sent the maximum and minimum intensities during this specific scan.
The method has recently been published by Thorseth and Kjeldstad (1999). To be able to compare
measurements performed with two very different instruments, special care has to be taken to correct
for instrumental characteristics. A technique for comparing spectroradiometers and multichannel nar-
row-band filter-radiometers has also been developed during phase 1 of COZUV and published recent-
ly (Thorseth et al., 2000). During a special campaign, sky-viewing pictures will be taken to document
different cloud conditions in addition to manual observations, which still is the most common way of


Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                  45
Chapter 6: Tasks and Methods

observing clouds from the ground.
Cosine error correction, necessary to improve uncertainty in all global irradiance measurements, will
be investigated at fractional cloud cover. Model studies have shown that input on realistic radiance
distribution is needed to correct for non-angular response (Thorseth, 2000; Landelius and Josefsson,
2000). Results on cosine error corrections can be retrieved from the setup described above. Figure
16 shows a comparison between a filterradiometer and a spectroradiometer under all weather condi-
tions where no cosine correction has been applied and a relative diurnal variation shows up in the af-
ternoon at clear sky conditions, less pronounced in the morning with cloudy conditions. The relative
difference in cosine error between the two instruments investigated is shown to the right in Figure 16.
The main focus of this task, which is planned to end in 2001, will be on measurements, analyses and
validation of the data. Modelling will be carried out for specific cases where information on cloud cov-
er, ozone, aerosols and surface albedo will be used as input parameters to a 3-D radiative transfer mod-
el (MYSTIC). The modelling will be done in co-operation with NILU.


Activity 7.4: UV radiation on a vertical surface
Responsible scientist: Arne Dahlback
Introduction
Solar UV radiation is usually measured on a horizontal plane surface. A horizontal surface is in most
cases not a realistic representation of the surface of human skin and other biological systems. Calcu-
lations have shown that exposure to solar UV radiation is strongly dependent on the surface geometry
(Dahlback and Moan, 1990). Measurements of UV radiation falling on a vertically oriented plane sur-
face is probably more representative for UV exposure of human face than measurements of radiation
falling on a horizontal surface. Measurements of UV radiation on vertical as well as on horizontal sur-
faces are of importance in the study of UV damage on human skin.
Objectives
The objective is to measure biologically effective UV doses on a vertical and a horizontal surface in
Oslo for at least one year. By combining the measurements with radiative transfer model calculations

                                                                          July 23.-98     340 nm                                      1.065
                        1.5                                  0.4
                                              Irradiance 340 nm




                                                             0.3                                                                       1.06          Clear sky morning
                       1.45
                                                                                                           Ratio GUV/Optronic OL752




                                                             0.2
                        1.4                                                                                                           1.055
  Ratio GUV/Optronic




                                                             0.1

                       1.35                                       0
                                                                      0        5        10     15     20
                                                                                         Time (hours)                                  1.05
                        1.3
                                                                                                                                      1.045
                       1.25

                        1.2                                                                                                            1.04                  Total diffuse limit

                       1.15
                                                                                                                                      1.035          Clear sky afternoon

                        1.1
                                                                                                                                       1.03
                          0   5     10                                    15                   20                                         40   50   60           70                80   90
                                  Time [UT]                                                                                                         Solar zenith,     0


  Figure 16. To the left: comparison of a multichannel filter and a slow scanning spectroradiometer during cloudy
  and clear sky conditions according to the method described in Thorseth and Kjeldstad (1999). To the right: simu-
  lation of a relative difference in cosine error at different diffuse radiation distributions. Solid line shows clear sky
  conditions, AM and PM situation.




46                                                                                  Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                      Ground based UV measurements


we will attempt to develop an algorithm that can be used to convert measured horizontal UV doses to
vertical UV doses. This algorithm will be applied on data from the Norwegian UV monitoring net-
work.
 Methods
We propose to perform high time resolution measurements with two 6-channel UV sensors for at least
one year. Two NILUUV 6-channel UV instruments will be located close to a Brewer MKV ozone
spectrophotometer and a GUV 5-channel UV instrument located on the roof of the Chemistry building
at the University of Oslo. The GUV instrument is part of the Norwegian UV monitoring network. One
NILUUV sensor will be oriented horizontally and one vertically. The sensor with the vertical surface
will be oriented in different azimuthal directions.
The NILUUV 6-channel instrument cover UV-B (280-320nm), UV-A (320-400nm) and PAR radia-
tion (Photosynthetically Active Radiation 400-700nm). The instrument is temperature stabilized and
the time resolution is 1 minute. The stability of the NILUUV sensor will be checked against a travel-
ling reference NILUUV instrument and against our Brewer spectroradiometer. During the project we
will collect data representing variable cloud cover and surface albedo conditions and solar zenith an-
gles from 90 to 36 degrees. For a period in the winter/spring we will consider to move the two NILU-
UV sensors to a place with high surface albedo, i.e. a place for which the surface is well covered with
snow. A multiple scattering radiative transfer model based on the discrete ordinate method will be an
important tool during the project.
The outcome of the project will be:
  • A. Compare vertical and horizontal biologically effective UV doses for different atmospheric and surface con-
       ditions and solar elevations.
  • B. Based on measurements during 1-2 years we will attempt to determine how time integrated UV doses vary
       with latitude under different atmospheric conditions.
  • C. Attempt to develop an algorithm to convert horizontal time-integrated UV doses measured by different sta-
       tions in the Norwegian UV monitoring network to vertical time-integrated UV doses.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                        47
Chapter 6: Tasks and Methods


Task 8: Airborne UV measurements
Task leader: Arve Kylling, NILU
Major objectives:
            • Fly an existing twelve channel UV instrument for one or two selected episodes each
              year.
            • Document the vertical distribution of UV radiation.
            • Study the effect of the vertical distribution of UV radiation on chemical reaction rates.
Relation to phase 1:
The activities of Task 8 are a direct continuation of the work carried out in COZUV-1. This task was
delayed during COZUV-1, so we want to catch up with this in COZUV-2.
Coupling to other parts of the project:
            Task 8 has indirect connection to several of the other tasks:
            1) the measurements of the vertical distribution of the actinic flux will constitute an im-
            portant data set against which the radiative schemes used in the atmospheric chemistry
            models in task 1 may be compared;
            2) depending on the origin of the flights the ozonesonde observations under task 3 and the
            ozone lidar observations under task 5 might be important for analysis of the flight data;
            3) the ground based UV measurements under task 7 are important for calibration and
            checking of the flight instrument.
The UV radiation field in the troposphere and the lower stratosphere will be measured by flying an
existing NILU-CUBE instrument on ozonesonde type balloons. The NILU-CUBE is a twelve channel
narrow-band filter instrument. It has six input optics, each mounted on the face of a cubical frame.
Each input optic has two channels, one in the UV-B centred at 312 nm, and one in the UV-A centred
at 340 nm. Both channels have a full width at half maximum (FWHM) of 10 nm. The instrument re-
ports results at five second intervals. It is not temperature stabilised, however, the temperature is meas-
ured on each of the six detector heads and reported simultaneously with the radiation signal. The
instrument is designed to fly on balloons and is hence very compact and lightweight. The instrument
is absolutely calibrated against a triad of NILU-UV instruments. The moderate bandwidth multichan-
nel NILU-UV filter radiometer is calibrated against an accurate spectroradiometer. The NILU-UV
measures the irradiance in six channels. Five have a bandwidth of 10 nm centred at 302, 312, 320, 340
and 380 nm. The sixth channel measures photosynthetic active radiation (PAR), 400-700 nm.
The NILU-CUBE will in august 2000 participate in a field campaign in Greece as part of the EU-fund-
ed ADMIRA project (Actinic flux determination from measurements of irradiance). As part of that
project the NILU-CUBE will be extensively compared with accurate spectroradiometer measure-
ments.
For the present project the instrument will be flown on balloon missions organised by Centre National
des Etudes Spatiales (CNES), France.
Possible launch sites are Andøya, Kiruna and sites in France. Simultaneous to the NILU-CUBE bal-
loon measurements a NILU-UV instrument will measure the UV radiation at the surface for the same
channels. The NILU-UV will serve both as a reference for checking the NILU-CUBE before and after
each flight, and as ground-truth during the flight. The presence of the NILU-UV will greatly ease the
post analysis of the NILU-CUBE data.


48                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                   Airborne UV measurements


The airborne UV measurements will be quality checked immediately after the flight. As the instru-
ment is not temperature stabilised, special attention will be paid to temperature effects and correction
for these. After the data has been assured to be of the best possible quality, the individual channels
will be corrected for their non-perfect angular response to yield the irradiance on each surface. From
the upward and downward pointing detectors an attempt will be made to derive the surface albedo.
Using the measured ozone profile and other available data the measurements will be compared with
accurate model calculations using the uvspec program (Mayer et al., 1997; Kylling et al., 1998;
www.libradtran.org). Based on the model/measurement comparison the actinic flux as a function of
altitude will be derived.




  The NILU-CUBE instrument. The left picture shows the total instrument assembly with the optical sensor and the
  data logging unit. The middle and right photos show close-ups of the optical sensor and logging unit, respectively.
  During flight both the logging unit and the optical sensor will be covered by styrofoam. Photo: Victor Dahl




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                               49
Chapter 6: Tasks and Methods


Task 9: UV modelling
Task leader: Arve Kylling, NILU
Major objectives:
            • To homogenize satellite and model information for input to radiative transfer algo-
              rithms.
            • To generate present UV maps of Norway using satellite information.
            • To generate future UV maps of Norway using chemistry model ozone column informa-
              tion together with satellite information.
            • To compare the present UV maps at selected locations with measurements.
Relation to phase 1:
Task 9 has been totally redefined compared the Task 9 of COZUV-1. The original Task 9 could not be
carried out due to lack of experimental data. Task 9 in the second phase of COZUV deals with UV
scenarios and is therefore totally new. This task makes a close link between the UV and ozone parts
of COZUV.
Coupling to other parts of the project:
            The task will receive input from Task 1 in terms of present and future model calculated
            ozone column fields.
            Task 9 is connected to task 7 and will use data collected under task 7 for validation.


Activity 9.1: UV scenarios
Responsible scientist: Arve Kylling
Taalas et al. (2000) have recently reported that relative to the 1979-92 period, springtime erythemal
UV doses may be up by 90% in the 2010-2020 time period between 60-90˚N. This increase is directly
related to predicted decreases in the ozone column from chemistry-climate model runs. Norway lies
within this latitude band where increased springtime UV may have detrimental effects to marine and
freshwater environments. Increased UV may have a negative effect on terrestrial plant life, and it
might lead to excess cases of both sunburn and snow blindness for humans. Furthermore UV radiation
can lead to skin cancer and reduced tolerance to certain infectious agents. In view of this it is proposed
to develop present and future UV maps covering Norway. The maps will be made on temporal and
spatial scales appropriate for biologists and physicians.
The main differences between these UV maps and those presented by Taalas et al. (2000) will be:
  • A. The maps will be made such as to allow a number of various doses to be calculated, not only the erythemal
       dose.
  • B. The present maps will be carefully compared with measurement from the Norwegian UV network to iden-
       tify periods and/or locations with problems and quantify these. Special care must be taken in the spring
       when there is snow on the ground.
The UV maps will provide the first UV maps over Norway that are checked against surface measure-
ments and the first detailed and versatile UV scenarios for Norway. They are expected to be of great
use for biologists and physicians. Collaboration with biologists and physicians already exist and will
be further strengthened within this task.




50                                        Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                            Coordination


Task 10: Coordination
Task leader: Geir O. Braathen, NILU
Major objectives and tasks:
            • To distribute the funds to the partners according to the budget determined by the Re-
              search Council.
            • To arrange a kick-off meeting, project progress meetings and a final seminar.
            • To follow the project progress through semi-annual reports from all the partners to the
              coordinator.
            • To collect reports from the task leaders that will be used for the annual reports and the
              final report to the Research Council.
            • To maintain the central data archive for the COZUV project at NILU.
            • To oversee that experimental data and model data from this project is submitted to the
              central database at NILU (NADIR) and that all the participants have access to these
              data. To oversee that other essential data (satellite data and ECMWF data) are made
              available.
            • To take an active part in the comparison between modelled and measured data.
            • To develop a publication plan and coordinate the dissemination of results from the
              project.
            • To maintain the COZUV web site (http://www.nilu.no/projects/cozuv)
Steering group
It is suggested that a steering group for COZUV be formed. Candidates for this group are: Ivar Isaksen
(modellers), Frode Stordal (data analysis, interpretation and validation), Bill Arlander (experimental-
ists), Berit Kjeldstad (UV) and Geir Braathen (coordinator). The steering group members will be in
contact much more frequently than the project meetings. The contact can take place in the form of
electronic mail or telephone meetings. Tasks for the steering groups are:
            • To oversee that the project progresses as planned
            • To prepare and plan project meetings
            • To suggest remedies if there are problems or difficulties
            • To oversee that the project web site contains sufficient and relevant information
Project secretary
In order to assist the coordinator it is suggested that one of the scientists in the project be assigned as
a scientific secretary in order to take some of the pressure off the coordinator. Tasks for the secretary
will be:
            • Preparation of material for the project meetings
            • Surveillance the central data archive
            • Routine maintenance of the project web site
            • Distribution of funds and handling of invoices




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                   51
Chapter 7: Couplings, benefits and international collaboration


CHAPTER 7:                        Couplings, benefits and interna-
                                  tional collaboration
7.1 Couplings
As described in chapter 6 for each task, there are several links between the various tasks of the project.
The diagram in Figure 17 shows these links in a graphical way. Task 6 is placed in the centre since it
requires input from most of the other tasks, but there are also links between several of the other tasks.



                                                                                  Figure 17. Links
                                                                                  between the various
                                                                                  tasks in the COZUV
                                                                                  project. Circles repre-
                                 1                                                sent observational


        5                                                       4
                                                                                  tasks, rectangles mod-
                                                                                  elling tasks and trian-
                                                                                  gles analysis tasks.
                                                                                  Task 6 is placed in the

                                                  7
                                                                                  centre since it plays a
                                                                                  pivotal role and re-

                                 6                                                quires input from most

                                                             8                    of the other tasks.




                   2                            9



                                     3

7.2 Benefits
There are several benefits of a joint Norwegian project:
            • There will be more interaction between the groups working within the field of strat-
              ospheric ozone and UV in Norway.
            • The interaction between modelling and observational activities in COZUV will give
              rise to a better understanding of the processes leading to ozone depletion and will con-
              tribute to an improvement of the models’ predictive capabilities.
            • There will be a better interaction between groups modelling UV and groups modelling
              chemistry.
            • There will be a more coherent coupling and contribution to international projects, such


52                                      Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                        International collaboration


              as EU projects within the field of stratospheric ozone and UV radiation.

7.3 International collaboration
The COZUV project, such as described in the present proposal is an independent project in its own
right. However, the results obtained through COZUV will also benefit other projects that the partners
participate in. All the groups in COZUV have extensive collaboration with other research groups in
Europe through the participation in the EU programme on stratospheric ozone and UV research. The
activities suggested in this proposal would strengthen the participation in these projects.

7.3.1 EU projects
Below follows a list of international projects where COZUV partners participate. In many of these
projects several Norwegian partners participate. We therefore give one common list of EU projects.
ADMIRA - Actinic flux Determination from Measurements of Irradiance
CRUSOE - Concerted Action for Scientific Strategy in the Stratosphere
EDUCE - European Database for Ultraviolet Radiation Climatology
GOA - Global Ozone Assimilation
Leewave-PSC - Study of polar stratospheric clouds formed in lee-waves
MAPSCORE - Mapping of Polar Stratospheric Clouds and Ozone Levels relevant to the region of Eu-
rope
MOZAIC II - Measurement of ozone by Airbus in-service aircraft
PAUR II- Photochemical activity and solar ultraviolet radiation
POET - Precursors of Ozone and Their Effects in the Troposphere
QUILT - Quantification and Interpretation of long-term UV/Vis Observations of the Atmosphere
ROCS - The role of ozone in the climate system.
SAMMOA- Spring-to-Autumn Measurements and Modelling of Ozone and Active Species
TOPOZ II- Towards the prediction of stratospheric ozone
UVAC - The influence of UV radiation and climate conditions on fish stocks - A case study of the
Northeast Arctic cod

7.3.2 Other collaboration
In addition to the specific projects listed above all the COZUV groups have long-term collaboration
with many research groups abroad, especially in Europe, Canada, Japan and USA. This collaboration
will benefit from the results obtained through COZUV.
7.3.2.1 UiO
The modelling group have extensive collaboration with other research groups in Europe through the
participation in the EU program on stratospheric ozone research. The modelling activities suggested
in this proposal would strengthen the participation in these projects.
The modelling group at the University of Oslo have close collaboration with prof. Michal Prather,
University of California during the development of the CTMs, and will continue the collaboration dur-



Coordinated Ozone and UV Project. Phase 2: 2001-2002                                            53
Chapter 7: Couplings, benefits and international collaboration

ing the project. We also have close collaboration with prof. W.-C. Wang on the climate-ozone relation,
which will benefit strongly from this project.
7.3.2.2 NILU
The ozone group at NILU collaborates with several modelling and observational groups. Within at-
mospheric chemistry modelling there has been a close collaboration with the Danish Meteorological
Institute in the field of microphysics and heterogeneous chemistry. There is also collaboration with
the National Centre for Atmospheric Research (NCAR) in Boulder, Colorado.
Within the field of ozonesonde observations there is close collaboration with the Finnish Meteorolog-
ical Institute, Sodankylä Observatory (Dr. E. Kyrö), Alfred Wegener Institute in Potsdam (Dr. P. von
der Gathen), the ozone observatory in Hohenpeissenberg (Dr. H. Claude) and the ozone group at the
University of Wales, Aberystwyth (Dr. G. Vaughan).
In the field of spectroscopic measurements there is close collaboration with the Service d’Aéronomie
of the CNRS in Verrières-le-Buisson (Dr. J.-P. Pommereau) and with the Belgian Institute for Space
Aeronomy in Brussels (Prof. P. Simon).
In the field of lidar measurements there is close collaboration with the Service d’Aéronomie of the
CNRS in Paris (Prof. Mégie) and with the Leibniz Institute for Atmospheric Physics, Kühlungsborn,
Germany (Prof. G. von Crossart).
The high resolution modelling studies of transport processes have been done in collaboration with the
NASA Jet Propulsion Laboratory and Langley Research Center (see Orsolini et al., 1997; Orsolini and
Grant, 2000).We have also a strong on-going collaboration with the Dept. of Atmospheric Sciences at
the University of Washington (Limpasuvan et al., 2000).
7.3.2.3 NTNU
Relevant for Task 7.3, NTNU will be submitting quality controlled spectral data and ancillary meas-
urements to the European database, EDUCE. Spectroradiometers used in the project will before the
project starts participate in a large Nordic intercomparison in Sweden in June 2000, where quality and
calibration of measurements will be performed. Kjeldstad has been working at UMIST Manchester
with Dr. Ann Webb for 11 months (ends July 2000) partly on spatial and temporal distribution of
clouds. This collaboration will continue and be valuable for work performed in Task 7.2. As a final
part of COZUV phase 1, Thorseth will spend some months at Dr. Blumthaler’s lab in Innsbruck where
he will learn more about radiation distribution measurements, which will be very useful for Task 7.1.
We assume that the collaboration can continue after his stay there.




54                                    Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                       Time schedule for individual tasks and activities


CHAPTER 8:                            Time schedule and milestones
The table below gives the time schedule for the project.

Table 8-1. Time schedule for individual tasks and activities

                                      Task/Year                                       2001       2002

                 Task 1: 3-D atmospheric chemistry modelling
 Activity 1.1:    Further development of a global 3-D CTM for stratospheric
                  process studies
 Development of new scheme for particles in Oslo CTM-2                            ✔     ✔
 Extension of the vertical range to 0.1hPa                                                   ✔     ✔
 Presentation of results                                                                ✔
 Activity 1.2: Long-term studies of stratospheric ozone depletion.
 Long-term integrations for the past (1970-2000) with SCTM-1                      ✔     ✔
 Long-term integrations for future scenarios until 2050 with SCTM-1                          ✔     ✔
 Presentation of results                                                                ✔          ✔
 Activity 1.3: Improvements of the stratospheric chemical transport model
 Inclusion of fast scheme for J-value calculations in SCMT-1                      ✔     ✔
 Update the gas phase chemistry in SCTM-1 and look at the effect                  ✔     ✔
 Presentation of results                                                                ✔          ✔
 Activity 1.4: Model studies of ozone loss processes
 Analysis of changes of spring and summer ozone with CTM-2 for the years                ✔    ✔     ✔
 1997,2000,2001
 Presentation of results                                                                ✔          ✔
 Activity 1.5: Provision of meteorological data
 Provision of 6-hourly T106 data from ECMWF on a daily basis.                     ✔      ✔   ✔     ✔

                           Task 2: Dynamical modelling
 Activity 2.1: Ozone transport and chemistry in spring and summer
 Model calculation of spring summer 2000                                          ✔     ✔
 Study of vortex break-down and debris                                                       ✔     ✔
 Presentation of results                                                                ✔          ✔
 Activity 2.2: Ozone mini-hole events
 Interannual variability of mini-holes during THESEO (1998-2000)                             ✔     ✔
 Presentation of results                                                                           ✔




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                55
Chapter 8: Time schedule and milestones

Table 8-1. (Continued) Time schedule for individual tasks and activities

                                      Task/Year                                              2001       2002

                           Task 3: Ozonesonde observations
 Activity 3.1: Climatological measurements
 Regular ozonesonde launches from Kjeller and Ørland                                     ✔      ✔   ✔     ✔
 Presentation of results                                                                       ✔          ✔
 Activity 3.2: Participation in international ozonesonde programmes
 2-3 launches per week during Match campaigns and under special meteorological con-      ✔          ✔
 ditions with special emphasis on the winter and spring
 Presentation of results                                                                       ✔          ✔

                            Task 4: DOAS measurements
 SAOZ measurements in Ny-Ålesund. August-October and February-April                      ✔      ✔   ✔     ✔
 SYMOCS-1 and SYMOCS-2 measurements at Andøya. Entire year                               ✔      ✔   ✔     ✔
 Improved air mass factors for ozone and NO2                                                   ✔
 Air mass factors for OClO and BrO                                                                  ✔
 Analysis of IO                                                                                           ✔
 Presentation of results                                                                       ✔          ✔

                       Task 5: Ozone lidar measurements
 Year-around measurements and analysis, special emphasis on winter/spring                ✔      ✔   ✔     ✔
 Presentation of results                                                                       ✔          ✔

                           Task 6: Analysis of ozone change
 Activity 6.1: Hemispheric data
 Hemispheric data will be collected on a continuous basis                                ✔      ✔   ✔     ✔
 Presentation of results                                                                       ✔          ✔
 Activity 6.2: Temporal development of the ozone mixing ratio on isentropic sur-
 faces
 Calculation of ozone loss for winters 00-01 and 01-02 at 400, 450, 475, 500 and 550 K         ✔          ✔
 Calculation of ozone loss for winters 88-89 to 99-00 at 400, 450, 500 and 550 K
 Presentation of results                                                                       ✔          ✔
 Activity 6.3: Comparison between modelled and observed ozone
 Calculation of chemical ozone loss based on data from each winter                             ✔          ✔
 Presentation of results                                                                       ✔          ✔




56                                          Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                         Time schedule for individual tasks and activities


Table 8-1. (Continued) Time schedule for individual tasks and activities

                                      Task/Year                                         2001       2002

                   Task 7: Ground based UV measurements
 Activity 7.1: Direct and global UV measurements in Trondheim as part of a
 European network.
 Improvement of input optic system for simultaneous direct and global                     ✔
 Measurements, quality control and submission of global irradiance data                   ✔    ✔     ✔
 Measurements, quality control of both direct and global UV                                    ✔     ✔
 Results from direct measurements, UV, aerosol and ozone                                             ✔
 Presentation of results                                                                  ✔          ✔
 Activity 7.2: UV radiance distribution in a sub-Arctic region
 Improvement of tracker system for radiance measurements                            ✔
 Tests and measurements                                                                   ✔
 Campaign at Andøya                                                                            ✔
 Presentation of results                                                                  ✔          ✔
 Activity 7.3: Impact of broken clouds on ground based UV irradiance; measure-
 ments, analyses and validation
 Results on intercomparison of cosine error correction (cont. from phase 1)         ✔
 Measurements during broken cloud conditions, testing of algorithm                  ✔     ✔
 Results of cosine correction during all weather conditions, including                    ✔
 broken clouds
 Presentation of results                                                                  ✔          ✔
 Activity 7.4: UV radiation on a vertical surface
 Measurements                                                                       ✔      ✔   ✔     ✔
 Modelling                                                                                ✔          ✔
 Presentation of results                                                                  ✔          ✔

                      Task 8: Airborne UV measurements
 Balloon launches of NILU-CUBE. One launch in early 2001 and one in early 2002.     ✔          ✔
 Data analysis                                                                            ✔          ✔
 Presentation of results                                                                  ✔          ✔

                                Task 9: UV modelling
 Act. 9.1: Effect of clouds on surface UV radiation
 Homogenisation of input data                                                       ✔
 Generation of UV maps                                                                    ✔
 Compare maps and measurements                                                                 ✔
 Presentation of results                                                                  ✔          ✔

                              Task 10: Coordination
 Arrangement of project meetings.                                                   ✔     ✔          ✔




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                  57
Chapter 8: Time schedule and milestones

Table 8-1. (Continued) Time schedule for individual tasks and activities

                                        Task/Year                                                  2001            2002
 Preparation of reports to NFR                                                                 ✔               ✔
 Oversee data flow and take part in model/measurement intercomparisons                          ✔       ✔       ✔       ✔
 Maintenance of web site                                                                       ✔       ✔       ✔       ✔



The table below gives the milestones for the project. The milestones will be in the form of analysis
results and reports and meetings where the project progress will be reviewed and discussed.
Table 8-2. Milestones

           Date                                                     Milestone
                           Information and planning meeting (“kick-off” meeting). This meeting is necessary in order
                           to inform all the partners on the objectives of the project and to define the tasks to be carried
 January          2001
                           out during the first 12 months. Each participant will be given well defined tasks and a time
                           plan for when to deliver results. A preliminary plan for publication of results will be made.

                           First annual report to the Norwegian Research Council will be submitted.
                           Preliminary results and individual partner reports from the first winter will be assessed by the
                           coordinator. Based on this information, a report for internal project use will be made by the
 September        2001
                           coordinator at this milestone and circulated to the partners for assessment. This milestone is
                           important since major problems at this stage should be identified so that they can be resolved
                           before the second year.

                           Meeting to review final results from the first winter. At this time all the results from the first
                           year will be available, so that they can be assessed by all the partners together. This meeting
 December         2001
                           will also be used for the planning of the second year. A plan for a new application to the
                           research council will be discussed.

 May              2002     Meeting for assessing preliminary data for winter 2001-02.

                           Second annual report to the Norwegian Research Council will be submitted.
                           Preliminary results and individual partner reports from the second winter will be assessed by
 September        2002
                           the coordinator. A report for internal project use will be made by the coordinator at this mile-
                           stone and circulated to the partners for assessment.

                           Final project seminar to review the final results from the second winter. At this time all the
                           results from the second year will be available, so that they can be assessed. This meeting will
 December         2002     also be used for the planning of the final report. Each participant will be given defined tasks
                           for their contributions to the final report. Possible publications that can come out of the
                           projects will be discussed.

 August           2003     Final report will be submitted to the Norwegian Research Council.




58                                             Coordinated Ozone and UV Project Phase 2: 2001-2002
CHAPTER 9:                           Dissemination of results
Results from the joint Norwegian project will be made available to a larger audience by several means:
  • A. By publication in peer-reviewed scientific journals.
  • B. By presentations at relevant international conferences.
  • C. By giving a real time picture of the ozone situation. Since satellite and ground based observations will give
       a near real time picture of stratospheric ozone in the Northern Hemisphere it has the potential to act as a
       warning system for low ozone. The low ozone measured in the Arctic during several of the most recent
       winters shows that there is a need for a warning system. Data from the project can be made available to
       Norwegian and other European environmental authorities if there is a need or wish for that.
  • D. By making results and some data available on the World Wide Web (WWW). By advertising results and
       sample data through this site the outcome of the project will be made available to a large audience. This
       leads to an increased public interest in the stratospheric ozone and UV problem and the research that is car-
       ried out in this field. The COZUV web site was established during phase 1 of COZUV and the address is:
       http://www.nilu.no/projects/cozuv
  • E. By extending a powerful, reliable and easy to use radiative transfer model to include three-dimensional
       cloud effects. The existing model is freely available on the web. The extended version will be made avail-
       able in the same manner.
  • F. Input to ozone and climate assessments.
There will also be emphasis on the timely exchange of data among the groups participating in
COZUV.


CHAPTER 10: Importance for policy issues
Norway has responsibilities under the Montreal protocol of the Vienna Convention and the Frame-
work Convention on Climate Change. Knowledge about the state of the ozone layer constitutes the
basis for negotiations and decisions on the political level concerning the phase-out of ozone depleting
substances.
The Intergovernmental Panel on Climate Change (IPCC) will consider aircraft impacts in its next re-
port. For these reasons, it is essential that there is a strong scientific effort in stratospheric research.
The present project will contribute to the knowledge which is necessary to formulate a sound environ-
mental policy which aims at protecting the environment both by quantifying the chemically-induced
ozone loss in the Arctic and at mid-latitudes. The improvement of numerical models, which is one of
the main goals of this proposal, is necessary for the prediction of future ozone loss. Such predictions
will have policy implications for the phase-out of ozone depleting substances.


CHAPTER 11: Budget
Below follows a detailed specification of the costs related to the various activities that we seek support
for.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                           59
Chapter 11: Budget

Table 11-1. Cost breakdown

                              Activity number                               Cost NOK
          Description                                  Person(s)
                               in Chapter 6
                                                                        2001        2002

                UiO
 Manpower. Dr. scient. fel-       1.1, 1.4        Gauss                   370000
 lowship

 Manpower                         1.2, 1.3        Rognerud                100000         100000

 Travel                              1.                                    20000          20000

 Computer equipment               1.1 - 1.4       Disk storage             60000          20000

 SUM UiO                                                                  550000         140000

       NILU Kjeller
 Manpower                           1.5           Bojkov                   40000          30000

 Manpower                         2.1, 2.2        Orsolini                182000         210000

 Manpower                           2.1           Fløisand                110000         130000

 Travel                           2.1, 2.2        Orsolini, Fløisand       10000          13000

 Manpower                         3.1, 3.2        Bojkov                  100000          80000

 Ozonesondes                      3.1, 3.2                                120000         100000

 Manpower                            4            Arlander                115000         130000

 Travel                              4            Arlander                  8500          10000

 Manpower                            4            Høiskar                  66000          80000

 Travel                              4            Høiskar                  10000          13000

 Manpower                           6.2           Braathen                 50000          57000

 Manpower                           6.3           Stordal                  65000          80000

 Travel                           6.2 - 6.4       Braathen, Stordal        14000          17000

 Manpower                            8            Danielsen + Kylling     190000         140000

 Equipment for NILU-CUBE             8                                     12000          13000

 Flight costs                        8                                     30000          10000

 Travel and subsistence              8                                     34000          17000

 Manpower                            9            Kylling                 105000         130000

 Travel and subsistence              9            Kylling                   8500          10000

 Coordination                        10           Braathen                190000         240000

 SUM NILU Kjeller                                                       1.460.000      1.510.000




60                                        Coordinated Ozone and UV Project Phase 2: 2001-2002
                                                                                              . Cost breakdown


Table 11-1. (Continued) Cost breakdown

                                 Activity number                                              Cost NOK
          Description                                          Person(s)
                                  in Chapter 6
                                                                                         2001              2002

      NILU Tromsø
 Manpower                                  5             Hansen                              58000             65000

 Manpower                                  5             Edvardsen                           65000             75000

 Manpower                                 6.1            Hansen                              45000             50000

 Manpower                                  8             Edvardsen                           18000             20000

 Travel and subsistence                    5             Hansen                              16000             20000

 Running costs at ALOMAR           5 (Ozone lidar +                                          28000             40000
                                    spectrometer)

 SUM NILU Tromsø                                                                            230000            270000

             FFI
 Manpower                                  5                                                 80000             80000

 Running costs at ALOMAR                   5                                                100000            100000

 Travels to ALOMAR                         5             Hoppe                               15000             15000

 SUM FFI                                                                                    195000            195000

            NTNU
 Manpower                                  7             Thorseth                           370000            125000

 Equipment and running                     7                                                 30000             20000
 costs

 Travel and subsistence for                7             Thorseth and Kjeldstad              20000             10000
 intercomparisons

 SUM NTNU                                                                                   420000            155000

  UiO, dept. of Physics
 Equipment                                7.4                                                10224             10000

 Rental of NILU-UV                        7.4                                                50000             50000

 Travel                                   7.4            Dahlback                            10000             10000

 SUM UiO                                                                                     70224             70000

 Total                                                                                   2.925.224          2.340.000

Comments to the budget for NTNU:
Trond Morten Thorseth will be paid as a postdoctoral fellow i for 75% of 2001. He will also be postdoc for three months
in 2002. He has then spent three years as a post-doctoral fellow.




Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                              61
Chapter 12: References


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Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                   63
Chapter 12: References

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Coordinated Ozone and UV Project. Phase 2: 2001-2002                                                                 65
Chapter 12: References




66                       Coordinated Ozone and UV Project Phase 2: 2001-2002

				
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