recalibrated ozone profiles from gome uv vis nadir spectra n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Recalibrated Ozone Profiles from GOME-UV/Vis Nadir spectra PowerPoint Presentation
Download Presentation
Recalibrated Ozone Profiles from GOME-UV/Vis Nadir spectra

Loading in 2 Seconds...

play fullscreen
1 / 19

Recalibrated Ozone Profiles from GOME-UV/Vis Nadir spectra - PowerPoint PPT Presentation


  • 106 Views
  • Uploaded on

ERS-ENVISAT Symposium, Salzburg, 6-10 Sep 2004. Recalibrated Ozone Profiles from GOME-UV/Vis Nadir spectra. Silvia Tellmann, Mark Weber , Vladimir Rozanov, and John Burrows Institute of Environmental Physics/ Institute of Remote Sensing University of Bremen. Overview.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Recalibrated Ozone Profiles from GOME-UV/Vis Nadir spectra' - cheche


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
recalibrated ozone profiles from gome uv vis nadir spectra

ERS-ENVISAT Symposium, Salzburg, 6-10 Sep 2004

Recalibrated Ozone Profiles from GOME-UV/Vis Nadir spectra
  • Silvia Tellmann, Mark Weber, Vladimir Rozanov,
  • and John Burrows
  • Institute of Environmental Physics/
  • Institute of Remote Sensing
  • University of Bremen
overview
Overview
  • O3 nadir profiling in Bremen
  • Calibration Problems in FURM V5
  • Improved calibration correction
    • low latitude approach
    • global approach
  • Improved tropospheric retrieval
  • Conclusion
gome o3 profile retrieval in bremen
GOME O3 profile retrieval in Bremen
  • Full Retrieval Method (FURM):
    • Optimal estimation and Kozlov information matrix approach & validation with ozone sonde data
        • R. Hoogen, V.V. Rozanov, J.P. Burrows, Ozone Profiles from GOME Satellite Data: Algorithm Description and First Validation, J. Geophys. Res., 104, 8263-8280, 1999.
        • R. Hoogen, V.V. Rozanov, K. Bramstedt, K.-U. Eichmann, M. Weber, and J.P. Burrows, Ozone profiles from GOME satellite data-I: Comparison with ozonesonde measurements, Physics and Chemistry of the Earth 24, 447-452, 1999.
    • Extensive validation of Version 5 with lidar and satellite data
        • K. Bramstedt, K.-U. Eichmann, M. Weber, V. Rozanov, and J. P. Burrows, GOME ozone profiles: A global validation with HALOE measurements, Adv. Space Res. 29, 1637-1642, 2002.
        • K. Bramstedt, J. Gleason, D. Loyola, W. Thomas, A. Bracher, M. Weber, and J. P. Burrows, Comparison of total ozone from the satellite instruments GOME and TOMS with measurements from the Dobson network 1996-2000, Atmospheric Chemistry and Physics 3, 1409-1419, 2003.
        • G. Hansen, K. Bramstedt, V. Rozanov, M. Weber, and J.P. Burrows, Validation of GOME ozone profiles by means of the ALOMAR ozone lidar, Annales Geophysicae 21, 1879-1886, 2003.
        • A. Bracher, M. Weber, K. Bramstedt, S. Tellmann, J. P. Burrows, Long-term global measurements of ozone profiles by GOME validated with SAGE II considering atmospheric dynamics, J. Geophys. Res., accepted, 2004.
gomeo3 profile retrieval in bremen ii
GOMEO3 profile retrieval in Bremen (II)
  • Application in scientific studies: Arctic ozone depletion, international field campaigns (OFP, THESEO2000), ozone miniholes
      • K.-U. Eichmann, K. Bramstedt, M. Weber, R. Hoogen, V.V. Rozanov, and J.P. Burrows, Structure of ozone mini-holes from GOME, European Symposium on Atmospheric Measurements from Space, Proc. ESAMS'99, ESA-WPP-161, 231-236, 1999.
      • K.-U. Eichmann, K. Bramstedt, M. Weber, V.V. Rozanov, R. Hoogen and J.P. Burrows, O3 profiles from GOME satellite data - II: Observations in the Arctic spring 1997 and 1998, Physics and Chemistry of the Earth 24, 453-457, 1999.
      • H. Bremer, M. von König, A. Kleinböhl, H. Küllmann, K. Künzi, K. Bramstedt, J. P. Burrows, K.-U. Eichmann, M. Weber, A. P. H. Goede, Ozone depletion observed by ASUR during the Arctic Winter 1999/2000, J. Geophys. Res. 107, 8277, doi:10.1029/2001JD000546, 2002.
      • K.-U. Eichmann, M. Weber, K. Bramstedt, and J.P. Burrows, Ozone depletion in the NH winter/spring 1999/2000 as measured by GOME-ERS2, J. Geophys. Res. 107, 8280, doi:10.1029/2001JD001148, 2002.
      • U. Klein, I. Wohltmann, K. Lindner, and K. F. Künzi, Ozone depletion and chlorine activation in the Arctic winter 1999/2000 observed in Ny-Ålesund, J. Geophys. Res., 107 (D20), 8288, doi:10.1029/2001JD000543, 2002.
  • Continued development: tropical retrieval (wavelength extension) and cloud/albedo effects, a-priori profile sensitivity
      • S. Tellmann, S., V.V. Rozanov, M. Weber, and J.P. Burrows, Improvements in the tropical ozone profile retrieval from GOME UV/vis nadir spectra, Adv. Space Res. 34, 739-743, 2004.
      • L. N. Lamsal, M. Weber, S. Tellmann, and J. P. Burrows, Ozone column classified climatology of ozone and temperature profiles based on ozonesonde and satellite data, J. Geophys. Res., accepted, 2004.
furm inversion scheme
FURM inversion scheme

O3-eigenvectors in altitude range

  • calculate ozone on several altitude levels large number of parameters: n  70
  • Develop the profile in a sum of eigenfunctions with proper truncation  n  10
  • Kozlov-Information-matrix-method combined with optimal estimation:

altitude [km]

O3-EV [-]

O3-eigenvectors in wavelength range

O3-EV [-]

Wavelength [nm]

radiometric calibration problems
Radiometric calibration problems

dichroic mirror

degradation

ratio of GOME solar spectra direct after launch and 5 years later

1.0

Ratio [-]

0.8

etalon

0.6

0.4

600

400

800

240

Wavelength [nm]

  • outgassing (mainly optical coatings e. g. dichroic mirror) change optical features
  • etalon structures: contamination layers on cooled detectors (ice) varies in time  spectral modulation
  • UV degradation of the instrument: scan mirror is exposed to UV-radiation
  • polarization degradation
furm v5 empirical calibration
FURM V5 empirical calibration

Chebychev Polynomials

0.1

  • wavelength range: 290 – 340 nm
  • broadband calibration correction to
  • allow for UVdegradation
  • Chebychev Polynomials

polynomials [-]

-0.1

-0.3

340

320

280

300

wavelength [nm]

Deviations between model and measurement

0.4

Channel 1

  • differential corrections:
  • NOT applied !!!!
  •  V5 restricted to wavelengths

0.2

residual [-]

0.0

-0.2

310

290

300

280

wavelength [nm]

shortcomings in furm v5
Shortcomings in FURM V5
  • lack of information in upper stratosphere (above 35-40 km)
  • problems in tropics where ozone maximum is shifted to
  • higher altitudes
  • wavelengths below 290 nm needed to enhance stratospheric
  • information content
  • Chebyshev polynomials inadequate at short wavelengths

ozone profiles in tropics

measurement sensitivity

Sensitive to measurement

50

FURM

SAGEII

Climatology

60

40

40

Altitude [km]

Altitude [km]

30

20

20

0

0.6

1.0

1.4

0.2

O3-concentration

Sum of rows AK-Matrix [-]

tropical calibration correction
Tropical calibration correction
  • large differential structures
  • below 290 nm
  • strong filling-in of
  • Fraunhofer lines

Differential sunnormalized radiance

5D-4

GOME

Model

3D-4

y_meas [-]

1D-4

-1D-4

290

280

285

275

residual & fit of diff. error

wavelength [nm]

GOME - Model

5D-4

Diff. error

  • New corrections by differential fit:
    • Fit addition error term:

a ~1/irradiance

    • 1/irr & polynomial fit before

ozone retrieval (prefit in Ch. 1)

3D-4

y_meas – y_model [-]

1D-4

-1D-4

285

290

275

280

wavelength [nm]

high latitude calibration correction
High latitude calibration correction

 Ozone maximum in middle and high latitudes shifted to lower altitudes and longer wavelengths

 low differential structure of ozone absorption

strong correlations between broadband calibration

 corrections and atmospheric parameter

 change of broadband calibration correction required below 300 nm statistical investigation of residuals

Mean residuals 1997-2003 in comparison with HALOE

1.0

0.8

0.6

Residual [-]

0.4

0.2

0.0

300

275

280

295

285

290

wavelength [nm]

results from 1997
Results from 1997

Relative deviations between standard version/new version and independent measurement from SAGE II (Stratospheric Aerosol and Gas Experiment II)

old results

Comparison of O3 [ppm] SAGE/FURM

50

50

0.3

Rel. Deviations New

Old

New

40

0.2

40

30

Altitude [km]

20

0.1

altitude [km]

30

new results

50

0.0

tropics

Rel. Deviations Old

40

20

Altitude [km]

-0.1

30

-0.2

10

20

0.4

0.6

0.0

-0.6

-0.4

-0.2

0.2

-40

-60

60

-20

0

20

40

2(SAGE-GOME)/(SAGE+GOME)

-0.3

latitude [deg]

results from 2003
Results from 2003

Relative deviations between SAGE II and FURM

old results

New Results

Comparison of O3 [ppm] SAGE/FURM

0.3

50

50

Old

New

0.2

40

45

Altitude [km]

30

40

0.1

20

35

altitude [km]

No of Pixel

0.0

30

new results

50

25

-0.1

40

20

Altitude [km]

30

-0.2

15

-0.4

-0.2

0.0

0.2

0.4

0.6

-0.6

20

2(SAGE-GOME)/(SAGE+GOME)

-0.3

No of Pixel

20

60

-40

-60

-20

0

40

latitude [deg]

tropospheric retrieval
Tropospheric retrieval

Ozone Profile Hohenpeissenberg

50

FURM

Sonde

Climatology

Aks for retrieval levels in troposphere

40

50

30

40

altitude [km]

20

30

altitude [km]

10

20

0

O3 Conc

10

retrieved tropospheric ozone always

quite near to climatological values

averaging kernels (AKs) indicate

where information in retrieved height

level comes from

0

Averaging Kernels [-]

tropospherical investigations
Tropospherical investigations
  • Profile fit: spectral window too large to make accurate tropospheric ozone fit
  • Use just channel 2 to improve tropospheric column fit
  • Two step retrieval:
    • Common ozone profile fit to get information about
    • stratospheric constituents.
    • 2. Use fitted profile and investigate residual in channel 2
    • (~320-335 nm) troposphere here defined up to ECMWF thermal tropopause
    • Make new diff. fit of tropospherical ozone column,
    • temperature and Ring (inelastic scattering)
sensitivity in channel 2
Sensitivity in Channel 2

0.04

Residual & Fit

0.00

Residual

Residual [-]

Fit all param.

-0.04

Trop. Col.

0.02

O3 WF fit [-]

New col.

0.00

Old col.

-0.02

0.002

Temp. Fit

0.000

T WF fit [-]

-0.002

0.02

Ring Fit

Ring WF fit [-]

0.00

-0.02

324

332

320

322

330

334

326

328

wavelength [nm]

tropospherical column results
Tropospherical Column Results

Relative Deviations between O3–Sonde and climatology as well as FURM

Hohenpeissenberg 1997

+

troposph. columns from

profile retrieval

troposph. columns from

differential fit in channel 2

regression line for

profile fit

regression line for step 2

differential fit in channel 2

Rel. deviations Sonde-FURM [-]

  • in most cases improvements
  • for very small differences
  • to climatological value
  • instabilities in differential fit (noise)

Rel. deviations Sonde-Climatology [-]

conclusions
Conclusions

 Stratospheric information content can be enhanced by combined

calibration concept in short wavelength region using

      • differential „dark current“ approach for tropics/southern anomaly
      • residual fit for middle and high latitudes.

 Tropospheric retrieval based upon two step approach

      • accurate stratospheric ozone fit
      • accurate fit of Ring & atm. Parameters
      • realistic climatological ozone profile form
  • Inclusion of new ozone a-priori climatology (Lamsal et al. 2004)
  • Reprocessing of GOME 1995-2003 in preparation (funding?)
  • First application to SCIAMACHY (Version 5)
a priori profile sensitivity
A-priori profile sensitivity

 IUP climatology (Lamsal et al., JGR, 2004)

  • F&K (Fortuin and Kelder, JGR, 1998)
        • Improvement in the lowermost stratosphere with IUP climatology
        • see also talk by Lamsal et al. (Abstract 353) for details on IUP O3 climatology

Hohenpeissenberg 1997

23 August 2002

sciamachy nadir application
SCIAMACHY nadir application

 limb retrieval V1.6 (Savigny et al., JAS, 2004)

  • FURM nadir retrieval Version 5
        • there are still outstanding issues regarding calibration
        • Visit poster by Bramstedt et al. (3P08-6) for more details

23 August 2002