Spectroscopic Study of Atmospheric Trace Gases Using PARIS-IR from by bloved

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									Spectroscopic Study of Atmospheric
 Trace Gases Using PARIS-IR from
Waterloo Atmospheric Observatory in
           2005 and 2006


 Dejian Fu, Kaley Walker, Keeyoon Sung, Chris Boone,
                    Peter Bernath
    Waterloo Atmospheric Observatory (WAO)

   Goals of WAO
     To observe the concentrations of atmospheric trace gases simultaneously
     To conduct measurements over large time scales for observing trends

     To assist in validating Atmospheric Chemistry Experiment Fourier Transform

      Spectrometer (ACE-FTS)
   Location of WAO
     The rooftop of the Center for Environmental and Information Technology,
     University of Waterloo (43.47º, 80.54ºW, 319 m above sea level)
   Main instruments at WAO
    1. Portable Atmospheric Research Interferometric Spectrometer, for the
      Infrared (PARIS-IR)
    2. ABB Bomem DA8 (MOPD = 50 cm, Near IR-Vis-UV)
   From PARIS-IR spectra, we have been able to retrieve 13 species:
    O3, HCl, CH4, N2O, H2O, HNO3, NO, NO2, CCl3F, CCl2F2, HF, CO, OCS
   Portable Instrument - PARIS-IR

            ACE Arctic Validation Campaigns




                                                mini-
                                              MANTRA
MANTRA                                        campaign
   2004
 balloon
campaign




                                                WAO
  Ground-based Observations of PARIS-IR

                                          Max. Res. : 0.02 cm-1
sun sensor                                Meas. Reg.: 750 – 4400 cm-1
solar                                     Max. Scan Speed: 2.5 cm/s
beam                                      Detectors : InSb and HgCdTe
                                                 ZnSe beam splitter



pointing
 mirror

azimuth                        control
             elevation
gimbal                         computer
              gimbal
                      GPS receiver
                                            pendulum arm
Spectra recorded on July 30th, 2005 at WAO

          O3

                           CO2
                             CH4
                          N2O
   HNO3
                          O3    HCl
                                            HF
                     NO




               CO2                    H2O
     Retrievals: Process of Going from Spectra
     to Trace Gas Concentration
     A retrieval code named SFIT2 (C. Rinsland et al). used for trace gas retrievals. It
     contains a line-by-line calculation program for the forward model and uses the
     optimal estimation method for the inverse algorithm (C. Rodgers et al. ).
                                           Adjust VMR Profile
                                                                                      No

a priori VMR profiles from TAO             Observed Spectra                 Discrepancy
p & T profile from NCEP and                          Optimal Estimation   within a specified
1976 USA standard atmosphere                                                convergence
                                                                              criterion
spectral line parameters                  Computed Spectra
(HITRAN2004)                                                                         yes
air mass (RAYTRACE)
                                                                           Output retrieval
altitude grid (29 layers)                                                      result
Volume Mixing Ratio (VMR)
National Centers for Environment Prediction (NCEP)
Toronto Atmospheric Observatory (TAO)
A Sample for CH4 Retrieval Using
Spectrum Recorded on July 30, 2005
                Residuals(%)
                                 4
                                 2
                                 0
                                -2
                                -4
                                     2859.3 2859.4 2859.5 2859.6 2859.7 2859.8 2859.9   2860   2860.1

                               1.1

                               1.0
   Amplitude (arbitary unit)




                               0.9

                               0.8

                               0.7

                               0.6

                               0.5
                                                                                          Meas Spec.
                                                                                          Calc. Spec.
                               0.4
                                     2859.3 2859.4 2859.5 2859.6 2859.7 2859.8 2859.9   2860   2860.1   (cm-1)
Column Densities Retrieved from Spectra
on July 30, 2005


                            Daily Mean Column
                            3.58 X 1019 molecules/cm2

                            1 s Standard Deviation
                            3.51 X 1017 molecules/cm2



                            Error bars indicate
                            total errors (systematic
                            and random errors).

                            Each data point is
                            obtained from 20
                            spectra recorded in 6.6
                            minutes.
      Characterization of CH4 Retrieval

                35


                30                                        12.5 - 100 km    Degree of freedom =2.07
                                                          0.31 - 12.5 km
                25
                                                          total Column
Altitude (km)




                20


                15


                10
                                                           CH4
                5                                          MW2835

                0
                     -0.2   0   0.2 0.4 0.6 0.8   1   1.2 1.4 1.6 1.8
                                 Averaging kernel values
           Characterization of O3 Retrieval

                50

                45                                        12.5 - 100 km
                                                                           Degree of freedom =1.02
                40                                        0.31 - 12.5 km
                35                                        total Column
Altitude (km)




                30

                25

                20

                15

                10                                         O3
                                                           MW2775
                5

                0
                     -0.2   0   0.2 0.4 0.6 0.8   1   1.2 1.4 1.6 1.8
                                 Averaging kernel values
Error Estimation
                                                     Errors (in %)
                  Error Sources                     CH4          O3
                                                   MW2835 MW2775
                           Retrieval Error          2.5         2.7
                          Solar Zenith Angle        <1          <1
 Random Errors
                             Temperature            <1          <1
                               Subtotal             2.8         3.0
                       Spectroscopic Parameter      2.0         5.0
                    Empirical Apodization Function  1.3         4.3
Systematic Errors
                                A priori            6.2         8.9
                               Subtotal             6.6         11.1
                   Total Error                      7.2         11.5
Total Ozone from MSC Brewer UV Spectrometer
at Toronto and PARIS-IR at WAO
                 500

                                                      MSC Daily Total Ozone
                                                      MSC Monthly Mean Ozone
                 450                                  PARIS-IR Daily Ozone
  Total Ozone (in DU)




                 400




                 350




                 300




                250
                05/01/01   05/04/01   05/07/01   05/10/01  06/01/01   06/04/01   06/07/01
                                             Date (YY/MM/DD)
Map of ACE Occultation Location within
1000 km from June 2005 to May 2006




                             12 coincident
                             ACE observations
Partial Column Densities of O3 from ACE and
PARIS-IR (17.5 km to 100 km)
                         300
                                    ACE-FTS
                                    ACE-MAESTRO (UV)
                         290        ACE-MAESTRO (Vis)
                                    PARIS-IR


                         280


                         270
  Total Column (in DU)




                         260
                                                        Agree to within 5%
                         250


                         240


                         230


                         220


                         210


                         200
                         26/06/05          03/07/05     10/07/05          17/07/05   24/07/05   31/07/05
                                                                   Date
Partial Column Densities of HCl from ACE
and PARIS-IR (17.5 km to 100 km)
                                        15
                                 x 10
                           3.4
                                                                                                ACE-FTS
                                                                                                PARIS-IR
                           3.3


                           3.2


                           3.1
 Total Column (in #/cm2)




                             3
                                                         Agree to within 5%
                           2.9


                           2.8


                           2.7


                           2.6


                           2.5


                            2.4
                           26/06/05          03/07/05   10/07/05          17/07/05   24/07/05         31/07/05
                                                                   Date
Partial Column Densities of HNO3 from
ACE and PARIS-IR (17.5 km to 100 km)
                           9.0
                                      ACE-FTS
                                      PARIS-IR




                           8.5
 Total Column (in #/cm2)




                           8.0

                                                      Differences between 2% and 12%

                           7.5




                           7.0




                            6.5
                           26/06/05              03/07/05    10/07/05          17/07/05   24/07/05   31/07/05
                                                                        Date
Summary and Future work

Completed
   50 days observations were performed using PARIS–IR at WAO from
    June 2005 to May 2006. 12 ACE occultations were recorded within
    1000 km of WAO.
   Column densities of 7 trace gases were retrieved using SFIT2 program.
   Good agreement of the results are achieved between PARIS–IR,
    Brewer, and ACE-FTS, ACE-MAESTRO measurements.
To do
   Observations and further analysis are on going at WAO.
   Correlations between species will be investigated.
   Simultaneous atmospheric observations using PARIS-IR and DA8 at
    WAO are in our plan.
Acknowledgements

   World Ozone and Ultraviolet Radiation Data Center

   Meteorological Service of Canada

   Natural Sciences and Engineering Research Council,
    Canada

   Canadian Space Agency

								
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