1. S5P tropical tropospheric ozone product based on convective cloud differential method Klaus-Peter Heue, Pieter Valks, Diego Loyola, Deutsches Zentrum für Luft- und Raumfahrt (DLR), IMF-ATP, Germany DLR.de Chart 1

2. CCD method DLR.de Chart 2 Troposphere<10 km (~280hPa) Cloud top height (ROCINN) Stratospheric VCD Above cloud VCD ~240 DU correctionVCD <2 DU Stratospheric VCD ~240 DU total VCD ~250-280 DU Tropospheric VCD ~10-40 DU

3. convective cloud differential (CCD) method  Look for high convective clouds (8.5km 0.8)  Column above the cloud is mainly stratospheric – Correct for column inside the cloud and between CT and 10km – Background region (70°E to 170°E) has low O 3 concentrations, low correction columns – Assume longitudinal constant stratospheric columns  Look for cloud free pixels (cloud cover <10%)  Average over 1.25°x 2.5° grid  Subtract stratospheric column (convective clouds) from total column (cloud free) Tropospheric Ozone DLR.de Chart 3

4. Stratospheric column May 2013 DLR.de Chart 4 Reference Region

5. Total Column May 2013 DLR.de Chart 5

6. Tropospheric Column May 2013 DLR.de Chart 6

7. Comparison to SCIAMACHY tropospheric data DLR.de Chart 7 Zonal means for sondes sometime consist of 1 or 2 stations! Offset of 20% added to GOME_CCD data to correct for different altitude ranges: SCIA 0-16 km CCD 0-10 km VCD =VMR*const*∆P The ratio of the pressure differences is 1.2 (offset of 20%) Difference SCIA-CCD ~2 DU (CCD is lower)

8. Typical comparison for GOME-2 CCD to sondes Slight offset ~2 DU Good agreement with annual cycle Comparison to ozone sondes (SHADOZ) DLR.de Chart 8

9. RAL Profile retrieved on a fixed grid: surface, 450, 170, 100 hpa, … RAL data scaled to 10 km (280 hPa) VCD[450-280hpa]=VCD[450-170hpa]/(450-170)*(450-280) VCDtrop=VCD[p>450]+VCD[450-280] Comparison to RAL profile retrieval for Sep 2007 DLR.de Chart 9 CCD GDP 4.8 RAL profile subcolumn below 10 km CCD minus RAL tropospheric subcolumn: -0.4 ± 3.15

10. Average difference between CCD and RAL profile DLR.de Chart 10

11. The tropospheric ozone CCD algorithm for S5P works Currently no S5P level-2 test data are available Validation by comparing GOME-2 data with other satellite retrievals o For the comparison with SCIAMACHY monthly means a correction term of +20% was introduces o Still the CCD data were lower than SCIAMACHY (~2 DU) o The sonde data were integrated up to 10 km for the comparison to CCD o The CCD data were higher by ~ 2 DU o GOME-2 data from RAL showed a good agreement until October 2007 o The CCD data are lower compared to RAL Comparison with SCIAMACHY gridded data is in progress. Summary DLR.de Chart 11

12. Extra slides DLR.de Chart 12

13. DLR.de Chart 13