MOST Microwave Observations of Stratosphere and Troposphere

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					          STEAM
 Stratosphere-Troposphere
Exchange And climate Monitor




         Scientific Approach
Scientific motivation
Odin heritage
STEAM concept
STEAM capabilities
Scientific ground-segment
Relevance to other missions and programmes
Synthesis




                                              2
Scientific Motivation




                        3
                  Background
 Chemical composition of the Earth atmosphere is
  changing as a result of human activities
 Direct impact on the environment activities
 Changes in the atmospheric composition in the Upper
  Troposphere and Lower Stratosphere (UTLS) are
  strongly coupled with climate change, and conversely
 Demand for accurate, global, height-resolved
  observations in the UTLS




                                                         4
                                Trends
                    Gz
                    l ve
                    oO
                    b o
                     a n
                     la
                     Ae
                      r
                      g
                      e
           1
           0
           3
                i7
                m
                b
                Nu
                 s
                 T
                 OS
                  M


           0
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           0             hS
                         re
                         aO
                         Pb
                          o
                          r
                         t T
                         E M
                               r
                               e
                               d
                               pi
                                c
                                t
                                ed
                               e
                               c
                               o
                               re
                                r
                                y
                                v

           9
           0
           2
Ozone(DbsUit)

           8
           0
           2
                         M
                         e
                         tM
                         e
                         o
                         rO
                          S
                          T


                9 9 0 0 0
                8 9 0 1 2
                0 0 0 0 0
                1 1 2 2 2
                    e
                    a
                    r
                    Y



                               Model
                 tropo




                               Strato
                               Meas.


                                         5
Radiative Forcing




                    6
                UTLS Dynamics




TT
L



TTL: Tropical Transition Layer               7
UTLS: Upper troposphere/Lower Stratosphere
UTSL Chemistry




                 8
                       MOZAIC Relative Humidity in UT over North Atlantic:
                                  Comparison with ECMWF




                                                            (ECMWF-MOZAIC)/MOZAIC x100%
                                                             Rel.Deviation ECMWF to MOZAIC
                                                                                             100
                  10
                           ECMWF              40N-60N                                         75                       40N-60N
                   8                                                                          50                 ECMWF-MOZAIC
Propability [%]




                                              MOZAIC                                          25
                   6
                                                                                               0
                   4                                                                          -25
                                                                                              -50
                   2
                                                                                              -75          Mean +/- Std.Dev.
                   0                                                                         -100
                       0     25 50 75 100 125 150 175                                               0   25 50 75 100 125 150 175
                              Relative Humidity [% , Ice]                                                Relative Humidity [% , Ice]



                           • MOZAIC provided the first climatology of UTH
                           • UT is much wetter than assumed before MOZAIC
                           • ECMWF does not reproduce ice super saturation



                                                                                                                                   9
  UTLS ozone : MOCAGE
  vs MOZAIC


MOZAIC




MOCAGE




                    10
MOZAIC



         Stratospheric
           Intrusion




                         11
        MIR SAOZ O3




Bauru, Brasil (22°S, 49°W)- Feb ‘01




                                      Tropopause




                                            12
          UTLS-Related Questions
 How and where does air undergo troposphere-to-stratosphere
  transport (TST)?
 What determines the chemical composition of the extratropical
  lower stratosphere?
 How is air processed during its passage through the TTL lower
  and what is its composition?
 How large is the UTLS oxidation capacity?
 How is air dehydrated during TST?
 How did the TTL change in the past and how will it change in the
  future?
 How will the UTLS affect climate change and conversely?




                                                                13
Frequency of clouds
              colder than 210 K




              colder than 190 K




                           14
                          Outlook
 Importance of the UTLS in the Earth Climate System
 Radiative, chemical et dynamical processes controlled
  by complex and coupled mecanisms
 Few UTLS measurements available with good precision
  and resolution:
   Satellites:
      Good measurements sensitivity either in the troposphere or in
       the stratosphere
      UTLS limitations due to the observation geometry and/or the
       presence of clouds
   Ground-based, Balloon-borne and air-borne instruments: good
    vertical resolution but no global coverage, and limited
    temporal coverage


                                                                       15
Odin Heritage




                16
             The Odin satellite

Mini-satellite
Swedish-led project, France, Canada and Finland
50 % aeronomy, 50% astronomy
250 kg
Sun synchronous orbit 18:00 hour ascending node
620 km altitude
Latitude coverage: 83°S-83°N
2 instruments :
   Microwave (SMR): 119 and 480-580 GHz
   UV/VIS and IR (OSIRIS): 200-700 nm and 1.27 mm
Target Molecules:
   O3, N2O, ClO, HNO3, daytime NO2, H2O and its isotopes, isotopes
    of O3, CO, and recently HO2 and NO
Launch in Feb. 2001 (START-1)


                                                               17
Odin




       18
     Odin Measurements at 500 K
O3    ClO    N2O    HNO3   SR NO2    SS NO2


                           No data   No data




                                               19
O3    ClO   N2O   O3    ClO    N2O




     Odin         3D CTM REPROBUS 20
D/H ratio in January 2002




                            21
Cloud detection by OSIRIS




                            22
 Odin
Feb ‘03




MIR SAOZ
           Tropopause
Feb ‘01




                        23
 Odin
Feb ‘03


          25
                                                                       5
                                                                                       5
          20
                                      -10
                                                                                  20
                       -20

          15    -10
MIR SAOZ                            -50         -50
                                                                40         -20
                                                                                           30
Feb ‘01 10       30


                                                        ²Z 360-340 K
           5
                                   O3 DEVIATION (%)

           0
               350           300     250      200      150      100              50             0


                      O3 MIR deviation wrt the zonal mean
                             Walker Circulation (Newel 1979)                                        24
REPROBUS (22°S) - Feb ‘03 -
       O3             H2O




       CO             N2O




                              25
STEAM Concept




                26
                    Preliminaries
 Swedish-Canadian-French concept (+ UK-Germany-Japan)
 Odin heritage in hardware [microwave (SMR) and
  UV/VIS-IR (OSIRIS)], human and science
 Microwave instrument
   2 channels
   320 GHz: H2O, O3, CO and N2O (UTLS)
   500 GHz: O3, ClO, H2O and isotopes (stratosphere)
 Optical instrument
   to complement the microwave instrument and improve the
    microwave measurement analysis in the presence of clouds
   8 channels: 450 nm-1.5 µm
   O3, H2O, aerosol and cloud property (UTLS)
   Stratospheric O3

                                                               27
              Scientific Issues
 UTLS and Stratosphere
 Radiative Budget
  H2O, O3, N2O, CO, clouds and aerosol
 Dynamical Processes
  H2O and isotopes, CO, O3, CH3Cl and N2O
  Stratosphere/Troposphere Exchanges
  Transport to/from high/mid/low latitudes
 Chemical Processes
  O3, ClO, CO, H2O, HNO3, CH3CN, HCN, N2O, clouds and aerosol
  Troposphere : O3 budget, emission (biomass and aircrafts)
  Stratosphere : monitoring of the O3 layer



                                                        28
            STEAM General Concept
 Target species
    UTLS: H2O, O3, CO, N2O, clouds and aerosols
    Stratosphere : O3, ClO, N2O, H2O and isotopes
 Mm channel
    High resolutions from 5 to 27 km
       Horizontal (< 50 km) and vertical (< 2 km)
 Sub-mm channel
    High resolutions from 15 to 40 km
       Horizontal (< 50 km) and vertical (< 2 km)
 Optical channels
    High resolutions from 5 to 40 km
       Horizontal (< 50 km) and vertical (< 2 km)
 Limb viewing with nadir option
 Orbit : 600 km, inclination ~97°, sunsynchronous, ascending node :
  18h00
 Launch: 2008, lifetime: 4 years

                                                                 29
Microwave Instrument




                       30
          Microwave instrument
 Mm channel (UTLS): 320-360 GHz
 Sub-mm channel (stratosphere): 485-505 GHz
 Double Band Mode
 Autocorrelator with 8 GHz total bandwidth and 10-
  20 MHz resolution
 Uncooled receivers (Trec ~3 000 K)
 Multiple Beam Detector
 Integration time: 2.5 s/measurements
 Simultaneous measurements of 2x4 predefined
  tangent heights
 Oversampling (Vertical resolution ~ 1.5 km)


                                                      31
   Measurement principle -1-
                                                 27,5                        27,5
                        26                                                        26
                                                  24,5                        24,5
                        23                                                        23
                                                  21,5                        21,5
                        20
Hauteur Tangente / km




                                                                                  20
                                                  18,5                        18,5
                        17                                                        17
                                                  15,5                        15,5
                        14                                                        14
                                                  12,5                        12,5
                        11                                                        11
                                                   9,5                            9,5
                         8                                                         8
                                                   6,5                            6,5
                         5                                                         5
                                                                                        1 cycle d e
                             2,5 s 2,5 s                  2,5 s   2,5 s
                                                                                        4 mesures
                                           déplacement
                                                                          bilan
                                            seco ndaire


                                                                                                      32
Measurement Principle -2-




                            33
Target Species : H2O, O3, CO and N2O
        item                                Frequency (GHz)
        Local Oscillator                    337.9
        Intermediate Frequency              5.9-13.9
        Lower sideband                      324.0-332.0
        Upper sideband                      343.8-351.8


        Constituents   Frequency (GHz)
        H2O-16         325.152
        CO             345.795
        O3             326.900, 327.844 , 349.743
        N2O            326.556, 351.667
        HNO3           ~331.9, ~344.5
        CH3CN              ~331.0, ~349.4
        CH3Cl          ~345.4
        (Cl-37-O)      ~346.9
        (OCS)          328.298


                                                              34
MM Channel




             35
Secondary species: HDO, HCN
            item                      Frequency (GHz)
            Local Oscillator          345.5
            Intermediate Frequency    5.9-13.9
            Lower sideband            331.6 - 339.6
            Upper sideband            351.4 - 359.4



Constituents         Frequency (GHz)
HDO                  335.395
O3                   332.704, 332.881, 335.271, 352.323, 352.592,
                     352.815, 355.018 , 357.629, 358.199, 358.750
N2O                  351.667
HNO3                 ~331.8, ~356.8
HCN                  354.505
(Cl-35-O)            ~352.85
(H2O-16)             336.222


                                                                    36
Secondary Species




                    37
                  Submm Channel
         item                         Frequency (GHz)
         Local Oscill ator            496.250
         Intermediate Frequency       2.75-6.75
         Lower sideband               489.5-493.5
         Upper sideband               499-503
               Table 5: Frequencies of the target sub-mm band.




Constituents    Frequency (GHz)
HDO             490.596
O3              491.950, 500.433
N2O             502.296
Cl-35-O         501.260
(BrO)           499.636


                                                                 38
Sub-mm Channel



                 Odin Window




                         39
          Retrievals: mm channel
 Cloud-free atmosphere
 1-D Retrievals (as for
  Odin)
 Tropopause : 12 km




                                   40
Optical instrument




                     41
  Microwave support & complement

Flag cloud-affected measurements
Characterize cloud influences to be included
 in the microwave measurement retrievals
Works in the sunlit part of the orbit
Detection & measurements
  Thin clouds
  Stratospheric aerosol
  Stratospheric ozone
  Water budget



                                                42
          Instrument concept

The CHAOS (Cloud, Height, Aerosol and
 Ozone Sensor) instrument
Cloud and aerosols from scattered light
O3 & H2O from extinction of scattered light
Limb view imaging (no scanning required)
Visible-Near IR: 450 nm-1.53 µm
Tomographic inversion




                                           43
                 CHAOS Channels
 Narrow band imagers at 1.27 and 1.53 µm
   Cloud layer, cloud top height and aerosol particles
   5-35 km with vert. and horiz. resol. of 0.2 and 50 km, resp.
 Narrow band imager at 1.36 µm
   H2O
   5-35 km with vert. and horiz. resol. of 0.2 and 50 km, resp.
 Imaging spectrographs at 450-500 nm and 600-900 nm
   Further caracterizion of cloud and aerosol particles through the
    spectral dependence of their scattering properties
   O3 in the Chappuis band (700-800 nm)
   5-50 km with vert. and horiz. resol. of 0.1-0.2 and 50 km, resp.
 Optical cloud 2D detector at 850 nm
   5-35 km with vert. and horiz. resol. of 0.2 and 0.1-10 km, resp.

                                                                   44
STEAM Capabilities




                     45
                                                                          Synthesis
                                                Stratosphere-Troposphere Exchange And climate Monitor (STEAM)
                                                    Vertical
                                                                                1.5-2.5 km                2.5-3.5 km                   > 3.5 km
                40                                  Resolution



                35


                30


                25
Altitude (km)




                20


                15
                                                                                                                                       Tropopause
                10


                 5


                 0




                                                                                                                                                  OCS
                                                    CO




                                                                                                                                       ClO
                                                                                                            HCN
                                                                                   HDO




                                                                                                                               CH3Cl
                           O3




                                                                                                                       CH3CN
                                                            H2O




                                                                                                   HNO3
                                                                                             N2O
                                     O3 nadir




                                                                    H2O nadir




                                                                                                                                                        Temperature
                     Integration Time : Limb (2.5 s), nadir (5 s); Tsys-3000 K



                                                                                                                                                                      46
                                  Requirements                                                     Bold=CHAOS

                     ACECHEM ACECHEM                                  STEAM
                                                                       STEAM

Variable    Domain   Uncertainty Horiz. Sampl. Vert. Res.   Uncertainty Horiz. Sampl. Vert. Res.

O3          LS       2-10%       50-100 km     2-3 km       5-10%       50 km         0.2/1.5-2.5 km
            UT       5-20%       50-100 km     2-3 km       20%         50 km         0.2/1.5-2.5 km

H2O         UT+LS    5-20%       50-100 km     2-3 km       10%         50 km         0.2/1.5-2.5 km

CO          UT+LS    5-20%       50-100 km     2-3 km       30%         50 km         2.5-3.5 km

N2O         UT+LS    5-10%       50-100 km     2-3 km       15%         50 km         1.5-2.5 km

HNO3        UT+LS    5-20%       50-100 km     2-3 km       20%         50 km         1.5-2.5 km

ClO         LS       5-20%       50-100 km     2-4 km       10%         50 km         2.5-3.5 km

Aerosol OD UT+LS     20-50%      50-100 km                  NA          50 km         0.2 km

Cirrus OD   UT       20-100%     25-100 km                  NA          50 km         0.2 km

Cloud occur. UT+LS               0.6-1.5 km    0.2-0.5 km   NA          0.1-10 km     0.2 km

            Meet the requirements                           OD: Optical Depth
                                                            NA: Not Available
            Almost meet the requirements                    LS: Lower Stratosphere
            Do not meet the requirements                    UT: Upper Troposphere                      47
     Scientific ground-segment

Retrieval
Modelling
Assimilation
Spectroscopy




                                 48
                         Retrieval
 1-D Retrieval (homogeneous atmosphere) -> 2-D
  Radiative Transfer and Retrieval (inhomogeneous
  atmosphere)
   Tomography
   Presence of clouds
   Diffusion




                                                    49
Vertical Resolution




                      50
Horizontal Resolution

       Odin   STEAM




                        51
Cloud effect




               52
                Modelling

Chemical Transport Model
  REPROBUS, MOCAGE, MIMOSA, …
General Circulation Model
  LMDz, ARPEGE, …
Mesoscale Models
  Meso-NH
Numerical Weather Prediction Models
  ECMWF




                                       53
                      Overshoots

         H2O (g/kg)                   H2O (g/kg)
     Resolving convection       Parameterized convection




                            Différ




3 km x 3 km mesoscale         30 km x 30 km mesoscale
simulation                    simulation
resolving convection          parameterised convection     54
PV section: tropopause folds and anticyclonic domes




                                                  55
                Assimilation

Constraining global model with global
 measurements in an optimal way
Methods
  3-D & 4-D Variational method
  Optimal Estimation method
Assimilation of
  L2 (geophysical parameters)
  L1B (brightness temperature)
  Families e.g. chlorine families require using L2
   data from different instruments and/or platforms


                                                  56
Odin O3 assimilation




                       57
                Spectroscopy

Laboratory studies
  France (Paris, Lille)
  Japan
  Germany
Broadening coefficients, temperature and
 pressure dependences for selected molecules
Continua




                                           58
Relevance to other missions, programmes




                                    59
Relevance to other missions, programmes
  Satellites
     Odin (2001)
     ENVISAT (2002)
        SCHIAMACHY, MIPAS, GOMOS
     EOS-AURA (2004)
        MLS, HIRDLS, TES, OMI
     METOP (2005), operational mission over 15 years
        IASI, MHS, GOME-2
     JEM-SMILES (2006)
     Future projects: GLORIA, GeoTrope, TROC, …
  Programmes
     MOZAIC (commercial aircrafts)
     SPARC, IPGC
     European programmes e.g. SCOUT-O3 and GMES (2004-2010)


                                                               60
                    Synthesis

 Apprehend the STEAM mission as part of a global
  satellite project to understand the Earth climate
  change by focussing on the UTLS processes
  (radiation budget, dynamics and chemistry) and, to a
  lesser extent, the monitoring of the O3 layer
 Focuss on the target compounds: O3, H2O, CO,
  N2O, clouds and aerosols
 Meet some of the objectives of the Montreal and
  the Kyoto Protocols




                                                         61
                  Global approach
 Processing
  As Near-Real Time as possible -> L1B (calibrated spectra), L2
   (geophysical parameter) and L4 (assimilated data)
  Onboard pre-processing
 Synergies
  Between Microwave and Optical Measurements
     Improvement of retrievals with the presence of clouds
     Global (planetary-scale) picture of O3, CO, H2O, N2O, clouds and
      aerosols
  With satellites
     Through the assimilation of other satellite data e.g. METOP/IASI
         • Complete planetary-scale coverage from the Earth surface to the
           stratosphere
         • O3, H2O, CO
  With Models
     Interpretation

                                                                         62
63
           Extratropical Tropopause

 12 km on the average at mid latitudes
 Coupled to the boundary layer by ascending
  transport along warm conveyor belt and
  convection
 Exchanges with stratosphere
   Convection
   Erosion of anticyclones
   Tropopause folds




                                               64
             Tropical transition layer

 Between 14 km and 18 km
 Deep convective clouds culminate within this region
 Slow radiative ascending motion outside clouds
 Presence of numerous subvisible cirrus clouds
 Input region to the stratosphere
 Dehydration of air entering the stratosphere (< 4 ppmv)
  through the cold tropopause




                                                     65
O3 budget & Tropopause Temperature

Tropospheric O3 is photochemically produced
 by CO, Nitrogen Oxides, CH4 oxidation (O3
 precursors)
O3 increases in polluted areas and
 transported over ocean
Importance of Temperature and Height of
 the Tropopause for the amount of H2O
 injected in the Stratosphere




                                           66
                  Team Composition
France
P. Ricaud         Observatoire de Bordeaux
                                                 Canada
J. de La Noë      Observatoire de Bordeaux
J. Urban          Observatoire de Bordeaux            E. J. Llewelyn   University of Saskatchevan
A. Hauchecorne    Service d’Aéronomie                 D. Degenstein    University of Saskatchevan
F. Lefèvre        Service d’Aéronomie                 N. Lloyd         University of Saskatchevan
G. Ancellet       Service d’Aéronomie                 D. Gattinger     University of Saskatchevan
C. Clerbaux       Service d’Aéronomie                 I. McDade        York University
D. Hauglustaine   LSCE                                C. von Savigny   York University
                                                      C. Haley         York University
V. Masson         LSCE
                                                      J. McConnell     York University
G. Beaudin        Observatoire de Paris-Meudon        B. Solheim       York University
M. Gheudin        Observatoire de Paris-Meudon        W. Evans         Trent University
J.-C. Lalaurie    CNES-Toulouse                       K. Strong        University of Toronto
B. Tatry          CNES-Toulouse
V.-H. Peuch       Météo-France
J.-M. Colmont     Université de Lill e

Sweden
D. Murtagh        Chalmers
P. Eriksson       Chalmers
R. Booth          Chalmers
U. Frisk          SSC
F. Sjöberg        SSC
G. Florin         SSC
J. Stegman        SSC
P. Baron          MISU
F. Merino         MISU
A. Emrich         Omnisys
H. Rodhe          MISU
N. Gustafsson     SMHI
M. Lindskog       SMHI
                                                                                                    67

				
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