1. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 1 K.-U. Eichmann, C. von Savigny, G. Rohen, J. Kaiser, H. Bovensmann, J.P. Burrows First retrieval of NIR CH4 profiles from SCIAMACHY measurements? Institute of Environmental Physics University of Bremen Germany

2. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 2

3. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 3 vertical resolution: 2.6 km horizontal resolution in azimuth direction: 240 km (120 km min.) horizontal resolution in flight direction: approx. 400 km Duration of Limb sequence: 60 sec. SCIAMACHY Limb Measurements Limb view for SOLSE/LORE instruments

4. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 4 Requirements UV-VIS-SWIR RTM Limb SCIATRAN/CDIPI (A. Rozanov 2001) SCIARAYs (Kaiser 2001) Refraction Full Sphericity Multiple Scattering  (double scattering) Ground Reflection Rayleigh, Mie-Scattering Analytical Weighting Functions  (In progress) Computational fast for global analysis of data  Occultation included Modelling the Radiative Transfer SCIARAYS: LBL mode, SFC included

5. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 5 Optimal Estimation x 0 : ln of the a priori O 3 profile x n : ln of the nth estimate y: ln of the measured Chappuis-Tripletts y n : ln of the modelled Chappuis-Tripletts for x n S x : covariance matrix of the a priori S  : covariance matrix of y K: Weighting function matrix y n and K will be determined by the radiative transfer model SCIARAYS [Kaiser, 2001] x n+1 = x 0 + S x K n T [K n S x K n T + S  ] -1 (y - y n - K n (x 0 -x n )) S = S x - S x K T [KS x K T + S  ] -1 KS x

6. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 6 Rozanov: Differential retrieval employing O 3 Huggins and Chappuis bands Savigny: 3 wavelength retrieval employing O 3 Chappuis bands Is SCIARAYS good enough?

7. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 7 CH4 x-section Ch. 6 (1000-1750 nm, 1.5 nm)

8. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 8 CH4 x-section channel 8 Ch. 8 (2265-2380 nm, 0.26 nm)

9. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 9 Convoluted x-section of CH4 Hitran 2000 database

10. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 10 VMR profiles of NIR absorbers Profiles from ACE study

11. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 11 Radiance at 6 km Tangent height CH4 (using SCIARAYS in LBL mode) CH4 (after slit function convolution) Red: H2O Blue: CO2

12. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 12 Radiance without CO2 and H2O Dotted Line: without CO2 and H2O

13. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 13 High resolution

14. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 14 Modelled Radiances after SFC Tangent heights every 3 km between 3 and 30 km (from top to bottom), Using SCIARAYS as a RTM.

15. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 15 Smoothed WF

16. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 16 WF @ 1666 nm

17. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 17 Different THs @ Channel 6

18. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 18 SCIAMACHY Level 1 measurements at 10 and 16 km TH = 10 km (twilight measurements) TH = 10 km (daytime measurements) TH = 16 km (daytime)

19. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 19 SCIAMACHY Level 1 measurements at 10 and 16 km TH = 10 km (twilight measurements) TH = 10 km (daytime measurements) TH = 16 km (daytime)

20. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 20 SCIA L1: 20 and 26 km With dead/bad pixels

21. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 21 Without dead/bad pixel 20 km 26 km

22. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 22 SCIAMACHY Channel 6: TH=65.8 km

23. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 23 One state (Ch. 6) at 85 km

24. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 24 Mesospheric OH emission lines Black: Night Red: Twilight Blue: Day

25. Institute for Environmental Physics and Remote Sensing (IUP/ife) Physics/Electrical Engineering 25 Conclusions NIR retrieval chain is not ready yet, but will be in the next few weeks. If it is possible to retrieve CH4 from Channel 6 (or Channel 8) from Limb measurements is still an open question. OH (both night and day emissions) seems to be a good candidate for further studies.