1. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 SCIAMACHY level-1 validation using radiometric calibration of balloonborne DOAS/LPMA spectrometers Level-1 Products: - solar irradiance (occultation geometry) - radiance (addition, nadir geometry) Cooperation: -LPMA Paris (C. Camy-Peyret) -IUP Heidelberg (K. Pfeilsticker) -IUP Heidelberg (T.Wagner) -IUP Bremen (A. Richter)

2. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 1) Calibration Lab has been set up with 3 fully certified and characterized reference sources (NIST & PTB) 2) Campaign sources can be calibrated in-house Solar irradiance calibration source for balloonborne occultation instruments LPMA and DOAS (campaign use, 300-2400 nm) beam geometry optimized Progress:

3. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 Method for measurement of TOA solar irradiance 1- radiometric calibration of ballonborne sensors 2- measurements in occultation geometry at various solar elevation angles 3- calculation of airmass-factors 4- extrapolation of airmass-factors to AMF = 0 using Langley-plot method 5- result is TOA (extraterrestrial) solar irradiance using balloonborne LPMA-DOAS in occultation

4. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 3) Additional sensors (nadir+zenith) : extended to airborne (AMAXDOAS) and ground-based (Bremen & Nairobi) DOAS for level-1 radiance validation (UV-VIS)

5. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 Radiometric calibration before and after flight to Kiruna

6. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 -radiometric calibration of sensors, then measurement -modelling radiation transfer (SCIATRAN) -using measured aerosol and trace gas data for realistic model absolute radiance measurement (ground-based DOAS Bremen) illustration of method (preliminary result) Method for radiance measurements

7. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 Winter 2003 Kiruna Campaign: solar irradiance measurements using absolute calibration of LPMA / DOAS TOA solar irradiance calculated using Langley-Plot (example, historic data)

8. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 Future Activities for LV-1 Validation -use of ground-based DOAS (zenith-sky) -use of airborne AMAXDOAS (nadir + zenith) -use of LPMA-DOAS balloon (occultation) -option: use of mini-DOAS balloon (nadir) Calibration stability of ground-based and airborne DOAS 3%, improvements possible Calibration stability of balloonborne LPMA, DOAS, mini DOAS not yet known

9. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 obtained in-situ by ballon-borne TDL (tunable diode laser) measurements with the CHILD c ompact h igh-altitude i nsitu l aser d iode Spectrometer Partners: -Univ. Heidelberg -TRIPLE (Jülich: C. Schiller, F. Stroh, Frankfurt A. Engel) Sciamachy validation using H 2 O and CH 4 profiles

10. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 of water vapor and methane profiles on TRIPLE flight from Aire sur L´Adour, 24.09.2002, (descent), matched with SCIAMACHY overpass Temporal resolution: 1 sec. for averaged data (2-4 meters altitude resolution) CHILD measurement

11. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 TRIPLE-flight with CHILD from ASA on 24-SEP-2002 <overpass SCIAMACHY - match at the middle of descent (30-40 hPa)

12. ______________________________________________________ IUP Univ. Bremen, W. Gurlit, Paris Meeting Nov. 2002 Future activities for the CHILD spectrometer....continue missions with TRIPLE