SAO OMI formaldehyde, water vapor and glyoxal retrievals

1. SAO OMI formaldehyde, water vapor and glyoxal retrievals Gonzalo Gonzalez Abad Helen Wang Christopher Miller Kelly Chance XiongLiu Thomas Kurosu OMI Science Team Meeting 12th March 2014

2. Summary • Formaldehyde • Updates to spectroscopy • Slant column fitting • Air mass factor calculation • Reference Sector Correction • Old vs. new SAO H2CO • Water vapor • Retrieval set up • Results • Early validation • Glyoxal • Retrieval set up • Results • OMI vs GOME-2 • New L2 files fields and information

3. H2CO spectroscopy updates High resolution solar spectrum H2CO cross sections

4. H2CO spectroscopy updates:O2-O2 collision complex cross sections

5. H2CO Slant Column Fitting Operational New version

6. H2CO Slant Column Fitting:Orbit #43214

7. Shared Air Mass Factor Calculation for H2CO, C2H2O2 and H2O • New lookup tables for scattering weights and TOA radiances calculated with Vlidort 2.4rt • 5 years OMLER albedo • OMI L1 surface height information • OMCLDO2 cloud information • Cloudy pixels  independent pixel approximation • Monthly GEOS-Chem climatology for 2007 • 340 nm for H2CO • 448 nm for C2H2O2 • 455 nm for H2O

8. H2CO AMF calculation: Orbit 8537 21st February 2006

9. H2CO AMF calculation: an example of scattering weights

10. H2CO reference sector correction

11. Old vs. new SOA H2CO product: Orbit #43214

12. H2CO time series and L3 comparison: old vs. new SAO retrievals

13. H2O retrieval set up

14. H2Oretrievalresults Open Ocean Coast Measured & fitted spectra Fitting residual Example retrieval result Fitted water vapor + residual Fitted liquid water + residual Fitted NO2 + residual Fitted O3 + residual

15. H2Oretrievalresults 20050714 20110714 20070714 20130714

16. H2Oretrieval validation efforts OMI Blue MODIS Near IR

17. H2Oretrieval validation efforts Comparison with AERONET time series

18. C2H2O2retrieval set up

19. C2H2O2 retrieval results

20. C2H2O2OMI vs. GOME-2 (Lerot et al.)

21. New fields in the SAO L2 file Albedo GasProfile ReferenceSectorCorrectedVerticalColumn XtrackQualityflags XtrackQualityflagsExpanded ScatteringWeights Gonzalez Abad et al., Atmos. Meas. Tech. Discuss., 7, 1-31, 2014 Wang at al., Atmos. Meas. Tech. Discuss., 7, 541-567, 2014 Miller at., in preparation

22. Thanks for your attentionWe would like to thank NASA for funding

23. Water vapor retrieval • Fitting window 430 – 480 nm • H2O, O3, NO2, CHOCHO, O2-O2, Liquid H2O, ring, water ring, 3rd order polynomials 2005-07-14 Typical SCD uncertainty: (1.0-1.7)×1022molec cm-2 Submitted to AMTD and accepted with corrections, H. Wang et. Al: Water Vapor Retrieval from OMI Visible Spectra

24. Post-processing reference sector correction

25. Row anomaly flags

26. SAO OMI H2O SCD sensitivityto retrieval window • SCD decreases by ~15% as window length increases from 20 nm to 65 nm. • The smallest uncertainty is achieved by the standard window of [430, 480]nm.

27. SAO OMI H2O sensitivity tointerfering molecules • The most important interfering molecules are liquid water, NO2 and O3.

28. C2H2O2de-stripping

29. C2H2O2 de-stripping

30. H2CO/C2H2O2ratio