1. SCIAMACHY satellite validation during the field campaigns CINDI and TRANSBROM Enno Peters, Folkard Wittrock, Andreas Richter, Mark Weber and John P. Burrows ENVIVAL-LIFE Meeting Bremen, 06/07.12.2010

2. I.Introduction 1.MAX-DOAS measurements 2.Instrumentation (the ENVIVAL sponsored instrument) II.The CINDI campaign 1.Campaign overview 2.Validation results (NO 2, Ozone) III.The TRANSBROM campaign 1.Transbrom campaign overview 2.Set up at ship, challenges 3.Validation results (NO 2, Ozone, HCHO) IV.Summary Outline

3. I.Introduction

4. MAX-DOAS measurements Multi Axis - Differential Optical Absorption Spectroscopy Measuring spectra of scattered sunlight Deriving trace gas columns and profiles from absorption features High sensitivity for stratospheric absorbers during twilight (  am and pm values) Light Y-shaped optical fibre Telescope unit Spectrometers Scheme of a MAX-DOAS instrument Zenith DOAS geometry

5. MAX-DOAS measurements Multi Axis - Differential Optical Absorption Spectroscopy Measuring spectra of scattered sunlight Deriving trace gas columns from absorption features High sensitivity for stratospheric absorbers during twilight (  am and pm values) High sensitivity for tropospheric absorbers using off-axis measurements Converting slant columns into vertical columns/profiles using radiative transfer models Light Y-shaped optical fibre Telescope unit Spectrometers Scheme of a MAX-DOAS instrument MAX-DOAS geometry

6. Optical bank with lens and optical fiber HgCd line lamp for calibration Video camera Entrance window (fused silica) Shutter for dark measurements, covered with PTFE (white) for calibration Telescope unit: 30x30 cm metal box mounted on Pan/Tilt Head (+- 90° elevation, +-180° azimuth, 100°/sec) The Bremen MAX-DOAS campaign instrument

7. Y-shaped optical fiber bundle in UV-spectrometer: 315 – 384 nm (0,033 nm/pixel, resolution ~ 0,4 nm) Vis-spectrometer: 400 – 573 nm (0,13 nm/pixel, resolution ~ 0,8 nm) The Bremen MAX-DOAS campaign instrument

8. II.The CINDI campaign

9. CINDI campaign - overview Participating institutes: 17 Host: KNMI (Royal Dutch Meteorological Institute) Location: Cabauw, Netherlands June/July 2009 Instruments: - 22 DOAS instruments - 4 NO/NOx in situ instruments - Lidars: Aerosol, NO2, trop. O 3 - meteorologic systems - several NO 2 sondes launched during campaign From Bremen: - 1 MAX-DOAS instrument - 1 NO/NO x in situ instrument Cabauw Intercomparison campaign of Nitrogen Dioxide (NO 2 ) measuring Instruments www.geomon.eu

10. CINDI campaign - overview Location: Cabauw, Netherlands 51 o 58' N 4 o 55' E (semirural area) Cabauw tower (in situ instruments, meteo data) Remote sensing site, (DOAS instruments, Lidars) 287° Boundary Layer ~ 1.5 km Elevation angle 2° 287° ~ 43 km

11. NO 2 tropospheric vertical columns NO 2 trop. VC June/July 09 over Cabauw MAX-DOAS SCIAMACHY (r = 50 km) GOME-2 (r = 50 km) Time resolution: 30 min Spatial resolution: Satellite data averaged within 50 km around site Period of (mostly) good weather (esp. June 24 & 25 “Golden Days”).

12. NO 2 tropospheric vertical columns NO 2 trop. VC over Cabauw MAX-DOAS SCIAMACHY (r = 50 km) GOME-2 (r = 50 km) “Golden Day” June 25  Zoom in

13. NO 2 tropospheric vertical columns NO 2 trop. Columns and ground layer (BREAM profiling) comparison at June 25, 2009 MAX-DOAS SCIAMACHY (r = 50 km) GOME-2 (r = 50 km) In situ monitor MAX-DOAS Ground Layer (profiling) For this day (almost no clouds, sunny) MAX-DOAS is successfully closing the gap between satellite measurements (huge spatial averaging) and in situ measurements (point measurements). Trop. Col. VMR (ppb) Morning inversion

14. NO 2 tropospheric vertical columns NO 2 trop. VC over Cabauw MAX-DOAS SCIAMACHY (r = 50 km) GOME-2 (r = 50 km) “Golden Day” June 25  Great (by chance?) June 29  Highly dependant an location of the satellite pixel

15. Total Ozone columns MAX-DOAS measurements SCIAMACHY GOME-2 Criterion for coincidence between Satellite and MAX-DOAS: Satellite pixel within 200 km around measurement site at day of respective MAX-DOAS measurements  average of these pixels

16. Total Ozone columns Criterion for coincidence between Satellite and MAX-DOAS: Satellite pixel within 200 km around measurement site at day of respective MAX-DOAS measurements  average of these pixels MAX-DOAS SCIAMACHY GOME-2

17. III.The TRANSBROM campaign

18. (Planned) Cruise track The TransBrom campaign RV „Sonne“ Campaign‘s Logo

19. 0° 180° 90° 270°  Relative winddirection between 90° and 180° is polluted (i.e. NO 2 ) x x Set up on the ship

20. NO 2 validation

21. Total NO 2 NO 2 vertical columns timeseries SCIAMACHY GOME-2 MAX-DOAS morning MAX DOAS evening monthly average (at ~ 10 LT) Criterion for coincidence: Satellite pixel within 200/400 km around ship‘s position at day of respective MAX-DOAS measurement  Oct 10-12 maybe too polluted (or clean)

22. Tropospheric NO 2 SZA < 75°, Fiterror < 20% Reference = closest 30° elevation spectrum (  tropospheric NO 2 content) NO 2 DSCD (298 K, 450 – 497 nm) 2° Elevation 8° Elevation 15° Elevation (Almost) no tropospheric NO 2 over open ocean

23. Tropospheric NO 2 SZA < 75°, Fiterror < 20% Reference = closest 30° elevation spectrum (  tropospheric NO 2 content) NO 2 DSCD (298 K, 450 – 497 nm) 2° Elevation 8° Elevation 15° Elevation

24. Tropospheric NO 2 SZA < 75°, Fiterror < 20% Reference = closest 30° elevation spectrum (  tropospheric NO 2 content) NO 2 DSCD (298 K, 450 – 497 nm) 2° Elevation 8° Elevation 15° Elevation Ship density 10.10.- 23.10.2009 Amver-data provided by Douglas Horton, CTR US Coast Guard Operations Systems Center (personal communication), www.amver.com

25. NO 2 DSCD, Oct 10-11 2° Elevation 8° Elevation 15° Elevation Rel. wind direction ok during event Positive peak 2° higher SC than upper elevation Camera picture:  Other ship‘s plume Relative wind direction Picture from the camera in the telescope box at 10.10.2009 23:20 UT Zoom in event Tropospheric NO 2

26. NO 2 tropospheric vertical columns NO 2 trop. VC, October 10 - 12 Detection Limit ~ MAX-DOAS GOME-2 (r = 150 km) SCIAMACHY (r = 150 km) monthly average (at ~ 10 LT) GOME2 trop. NO 2 October 2009

27. NO 2 tropospheric vertical columns NO 2 trop. VC, October 10 - 12 MAX-DOAS GOME-2 (r = 150 km) SCIAMACHY (r = 150 km) SCIAMACHY (r = 200 km) monthly average (at ~ 10 LT) GOME2 trop. NO 2 October 2009 Detection Limit ~

28. Ozone validation

29. Total Ozone columns MAX-DOAS measurements SCIAMACHY GOME-2 Criterion for coincidence between Satellite and MAX-DOAS: Satellite pixel within 200 km (400 km) around ship‘s position at 10 LT at day of respective MAX-DOAS measurements  average of these pixels

30. HCHO validation

31. HCHO differential slant columns anthropogenic, vegetation, lots of bush fires (dry season) Polluted region (ship traffic, influence from land) ? October 14: Sunniest day of the cruise HCHO VCD (335 – 357 nm)

32. HCHO tropospheric vertical columns Oct 19: HCHO transport from vegetation (rainforest)? HCHO VCD (335 – 357 nm) Oct 19-20 cruise track October 19 October 20 ~ 150 km Detection Limit for vertical column ~

33. HCHO tropospheric vertical columns HCHO from Satellite and MAX-DOAS MAX-DOAS (9-11 LT) Satellite (GOME-2) Data binned to 2°-grid. „Delay“ in MAX-DOAS increase probably due to bad weather at this time of the cruise.

34. HCHO tropospheric vertical columns  obtained HCHO-column along ship track is pure background signal!

35. IV.Summary

36. Summary Validation (total Ozone, NO 2 & HCHO) during 2 field campains in 2009 has been perfomed. CINDI campaign SCIAMCHY and MAX-DOAS Ozone have same shape, MAX-DOAS VCs mostly smaller than SCIAMACHY values Loss (and recovery) of 80 DU Ozone seen by both Satellite and MAX-DOAS At particular days MAX-DOAS (via profiling, BREAM) is able to close the gap between in situ point measurements and satellite(s) measurements of tropospheric NO 2 TRANSBROM SCIAMACHY and GOME-2 Ozone in good agreement with each other, smoothed compared to MAX-DOAS NO 2 from SCIAMACHY and GOME-2 in good agreement with each other and MAX-DOAS, even tropospheric NO 2 HCHO background level during whole campaign (from methane oxidation) in good agreement with GOME-2

37. Thank you!