1 COST 723 WG1 Meeting 1 October 6-7, 2003 University of Bern, CH Availability of UTLS relevant SCIAMACHY data C. von Savigny, A. Rozanov, A. Ladtstätter, A. Richter, K.-U. Eichmann, and John P. Burrows Institute of Environmental Physics and Remote Sensing IUP/ife UB Department 1 Physics/Electrical Engineering Institute of Environmental Physics and Institute of Remote Sensing University of Bremen

2 Outline SCIAMACHY – instrument features Deliverable data: - Ozone - NO2, SO2, BrO, Cloud information Under Development: - H2O

3 The SCIAMACHY Instrument Features: UV/Vis/NIR grating spectrometers: nm Moderate spectral resolution: 0.2 – 1.5 nm 8 channels: 8000 spectral points Measurements: –Atmospheric radiance: scattered, reflected and transmitted sunlight –Extraterrestrial solar irradiance –Lunar radiance

4 SCIAMACHY Measurement Geometries Typical spatial resolution in nadir: 30 km x 60 km Global coverage for limb and nadir within 6 days Special feature: nadir-limb matching

5 SCIAMACHY Limb Geometry Vertical resolution: 2.6 km Horizontal resolution in azimuth direction: 240 km (120 km min.), 960 km swath Horizontal resolution in flight direction: approx. 400 km Observation optimised to match limb with nadir measurements Duration of Limb sequence: 60 sec

6 Spectral Coverage and detectable Species

7 Retrieval from Limb Measurements

–370 nm: Ozone Useful height range: 5—50 km Above 12 km all information comes from the measurement No smoothing Averaging Kernels Limb

9 Ozone, comparison with Ozone Sondes 24 July 2002, Ny-Alesund 6 November 2002, Hohenpeissenberg C.von Savigny A. Rozanov

10 Comparison: SCIAMACHY - SHADOZ-Measurements SHADOZ(Southern Hemisphere Additional Ozonsondes), A. Thompson et al A. Ladtstätter-Weissenmeyer

11 Validation timespan: September / October 2002 Colocation criteria: tangent point within of 500 km HALOE on UARS POAM III on SPOT-4 Validation of stratospheric Ozone Profiles Limb Measurements Optimal Estimation C.von Savigny A. Bracher

12 BrO Cross-Section along Orbit 3008 A. Rozanov

13 Clouds detected from the VIS vs. NIR Latitude: 11.7° N Jump in radiance at about 15 km is due to clouds (Mie scattering) Color ratio 1090/750 nm C.von Savigny

14 Employ color-index: CI = LR(1090 nm) / LR(750 nm) Detection of PSCs by Color Index background C.von Savigny

15 Water Vapour Signatures Limb spectra from 0 to 42 km Every 3 km Clear signatures Of H2O in the UTLS region

16 Trace gases from Nadir Measurements

17 SCIAMACHY NO2 Nadir Measurements DOAS Retrieval

18 SCIAMACHY SO2

19 Summary Scientific Retrieval of SCIAMACHY UV/vis limb results works nicely for O3, NO2, BrO Ozone is measureable down to about 14 km in the tropics and 10 km at higher latitudes Clouds are the limiting factor for the retrieval of the UTLS region Water vapour retrieval is currently under development Scientific DOAS analysis of SCIAMACHY UV/vis nadir results works nicely for NO2, SO2, and O3 UV Results for NO2 and SO2 are very promising and show the potential of SCIAMACHY for tropospheric measurements