1. Goddard Space Flight Center Ocean Color Reprocessing Bryan Franz Ocean Biology Processing Group NASA Goddard Space Flight Center

2. Goddard Space Flight Center 2 Contents reprocessing overview known issues proposed changes preliminary results international collaborations

3. Goddard Space Flight Center 3 Overview Scope: sensors: MODISA, MODIST, SeaWiFS, OCTS, CZCS suites: OC, PAR, CLCT, FLH, POC, ZEU, IOP Highlights: sensor calibration updates (instrument aging, new insights) vicarious calibration updates (new MOBY data) new aerosol models based on AERONET NO2 corrections change MODIS nominal band center traceability & reproducibility of all inputs

4. Goddard Space Flight Center 4 We're not doing bad "as is" "first, do no harm" --Hippocrates SeaWiFS MODISA SubsetNRatioAPD All20041.1837% Deep4660.9929% SubsetNRatioAPD All5891.1539% Deep890.9121%

5. Goddard Space Flight Center 5 Known Issues 0.01 - 0.02 mg m -3 MODIS and SeaWiFS Oligotrophic Chlorophyll

6. Goddard Space Flight Center 6 Known Issues 551 vs 555 667 vs 670 MODIS and SeaWiFS Deep-Water Lwn Ratios

7. Goddard Space Flight Center 7 Known Issues  FLH Mean FLH = 0.005 MODIS Fluorescence Line Height Global Deep-Water Anomaly Trend Mission Time 2004 2007 2006 20%

8. Goddard Space Flight Center 8 Changes

9. Goddard Space Flight Center 9 Aerosol Models based on AERONET size distributions & albedos 70 models (7 humidities x 10 size fractions) model selection descriminated by relative humidity vector RT code accounting for polarization same code used for Rayleigh LUTs c50 c90 Current S&F Size Distributions AeroNET Size Distributions

10. Goddard Space Flight Center 10 Revised Out-of-Band Corrections 551 547 Revised Band Center

11. Goddard Space Flight Center 11 YearTime 199812:04 199912:02 200012:00 200112:01 200212:03 200312:08 200412:15 200512:25 200612:36 200712:50 200813:09 200913:32 201014:02 201114:38 201215:22 Node Crossing Time SeaWiFS Orbit orbit has drifted to a 1:30 p.m. node crossing impact to:  attitude system (Sun sensors)  solar diffuser calibration  thermal environment  solar path geometry

12. Goddard Space Flight Center 12 SeaWiFS Orbit YearTime 199812:04 199912:02 200012:00 200112:01 200212:03 200312:08 200412:15 200512:25 200612:36 200712:50 200813:09 200913:32 201014:02 201114:38 201215:22 Node Crossing Time

13. Goddard Space Flight Center 13 SeaWiFS Temporal Calibration - Current Operational Model Lunar Observations

14. Goddard Space Flight Center 14 SeaWiFS Temporal Calibration - Revised

15. Goddard Space Flight Center 15 SeaWiFS Temporal Calibration Issue

16. Goddard Space Flight Center 16 Uncertainty in SeaWiFS nLw Trends

17. Goddard Space Flight Center 17 Uncertainty in SeaWiFS Chl Trends OC3 OC4

18. Goddard Space Flight Center 18 Uncertainty in SeaWiFS Chl Trends Oligotrophic Eutrophic OC3 OC4 Mesotrophic variation in retrieved chl trend due to uncertainty in lunar-view to earth-view gain ratio at 765nm.

19. Goddard Space Flight Center 19 Other Changes MODISA calibrations  unknown temporal trend in Red-NIR RVS  recharacterize polarization sensitivity, 412 drift NO2 corrections  Ahmad et al. (2007) Appl. Opt.  extensive effort to produce/qc filled gome-schiamachy-omi dataset  0-10 % effects on Lwn, mostly coastal and high latitude Updates to ancillary fields  best available ozone and met data, new dependency on RH Reduction of SeaWiFS "straylight" speckling issues  outlier-resistant Level-3 binning strategies Updated OCx chlorophyll & Kd algorithms based on NOMAD V2

20. Goddard Space Flight Center 20 Results

21. Goddard Space Flight Center 21 SeaWiFS Deep-Water In situ Match-up Stats Product Med Ratio APD N Slope Intercept R-Squared Lwn412 1.0149 12.4190 171 1.0526 -0.0259 0.8801 Lwn443 0.9453 16.1420 252 1.0219 -0.0908 0.8112 Lwn490 0.9222 13.2710 251 0.9125 0.0167 0.7196 Lwn510 0.9548 13.8035 142 0.9172 0.0302 0.4385 Lwn555 0.9590 16.4210 252 0.7742 0.0653 0.6453 Lwn670 1.6866 79.9820 248 1.2104 0.0121 0.4412 chlorophyll 0.9995 29.8490 466 0.8834 -0.1714 0.7892 aot865 1.4177 42.3055 60 1.4115 Product Med Ratio APD N Slope Intercept R-Squared Lwn412 1.0013 11.7425 160 1.0148 -0.0181 0.8886 Lwn443 0.9418 16.3365 238 1.0393 -0.1221 0.8198 Lwn490 0.9119 14.5100 237 0.9390 -0.0279 0.7206 Lwn510 0.9767 13.4330 133 0.9508 0.0005 0.4568 Lwn555 0.9450 18.0115 238 0.7707 0.0637 0.6413 Lwn670 1.5503 75.4955 234 1.2204 0.0113 0.4547 chlorophyll 0.9944 26.4870 423 0.8749 -0.2078 0.7931 aot865 1.0631 25.1590 57 1.0583 -0.0028 0.7360 Operational Processing Configuration Current Baseline Reprocessing Configuration

22. Goddard Space Flight Center 22 Improved Aerosol Retrievals Improved AOT and Angstrom Comparisons Chlorophyll Unchanged SeaWiFS Lower Cheseapeake Bay Time-Series after before after before

23. Goddard Space Flight Center 23 after before after before Chlorophyll Unchanged Even Better Using Regional Aerosol Models SeaWiFS Lower Cheseapeake Bay Time-Series Improved Aerosol Retrievals

24. Goddard Space Flight Center 24 Improved Agreement Between Sensors more work TBD on MODISA calibration Mean Deep-Water Lw Ratio Trends

25. Goddard Space Flight Center 25 SeaWiFS Red-Band Issue MODISA SeaWiFS Eutrophic

26. Goddard Space Flight Center 26 Before After Mission Time Improved Agreement Between Sensors Mean Oligotrophic Chlorophyll Trends Mean Diff = 0.006 mg m -3 Mean Diff = 0.013 mg m -3

27. Goddard Space Flight Center 27 Other Missions MODIST  see Franz et al. (2008) J. Appl. Rem. Sens.  see Kwiatkowska et al. (2008) Appl. Opt.  make changes consistent with MODISA  regenerate vicarious instrument characterization CZCS  update vicarious calibration (model-based)  reprocess with latest tables, algorithms, flags & masks OCTS  update vicarious calibration (model-based)  reprocess with latest tables, algorithms, flags & masks

28. Goddard Space Flight Center 28 Summary it’s a big job!  SeaWiFS (11+ years), MODISA (6+ years), MODIST (9+ years)  instruments aging, orbits changing first complete end-to-end re-evaluation and update of ocean color processing methodology, radiative transfer tables, sensor cal, ancillary sources, file formats, etc. good progress and demonstrated improvements to date. more details and full analyses will be posted online for community comment and feedback. start reprocessing of SeaWiFS and MODISA within few months, then MODIST, SST, legacy missions, PAR, IOPs, etc.

29. Goddard Space Flight Center 29 International Collaborations keeping the time-series alive

30. Goddard Space Flight Center 30 ESA-NASA Collaborations on MERIS G. Meister & B. Franz members of MERIS Quality Working Group providing review and analysis for MERIS reprocessing sharing ideas and gaining insight CoastColor OBPG applied to be a "champion user" for MERIS full resolution data access to archive of 300-meter Chesapeake Bay scenes awaiting ESA decision SeaDAS MERIS display support added MERIS processing capability developed

31. Goddard Space Flight Center 31 MERIS Processed with NASA Algorithms OC4 Chlorophyll RGB

32. Goddard Space Flight Center 32 ISRO-NASA Collaborations on OCM OCM-2 is global 1-km, 8-band tilting CCD with lunar calibration Implementing arrangements in development for OCM-2  ISRO-NASA & ISRO-NOAA ISRO to provide online access to global OCM-2 data (4km) at Level-1B for research use, to all international users, at no cost. NASA to provide processing capability (Level-1B through Level-3) for use by ISRO and the international community (SeaDAS).  preliminary capability based on OCM-1 already implemented  need ISRO to finalize Level-1B format NASA & NOAA to participate in Joint Cal/Val Team

33. Goddard Space Flight Center 33 Thank You

34. Goddard Space Flight Center 34 Aerosol Models R vf R vc σfσf σcσc C vf C vc R vf : Geometric mean radius (fine mode) σ f : Geometric standard dev. (fine mode) C vf : Max value of the fine mode dist. R cf : Geometric mean radius (coarse mode) σ c : Geometric standard dev. (coarse mode) C cf : Max value of the coarse mode dist. f vf = C vf /(C vf +C vc ): Fraction of fine mode f vc = 1-f vf : Fraction of coarse mode

35. Goddard Space Flight Center 35 Aerosol Models SERC Wallop Island COVE Modal Radius Standard Deviation Effective Radius Fine Mode Fraction

36. Goddard Space Flight Center 36 Aerosol Models Fine Mode Coarse Mode

37. Goddard Space Flight Center 37 Spectral Out-of-Band Corrections

38. Goddard Space Flight Center 38 SeaWiFS Temporal Calibration

39. Goddard Space Flight Center 39 Comparison with Morel (Ca=0.065) MODISA: Theoretical nLw(547) = 0.319248 Observed nLw(547) = 0.320000 Theoretical nLw(667) = 0.0173954 Observed nLw(667) = 0.0230000 SeaWiFS: Theoretical nLw(555) = 0.269945 Observed nLw(555) = 0.305000 Theoretical nLw(670) = 0.0167871 Observed nLw(670) = 0.0400000

40. Goddard Space Flight Center 40 Uncertainty in SeaWiFS Chl Trends Oligotrophic Eutrophic Comparison Ratio OC3 OC4

41. Goddard Space Flight Center 41 Effect of a Known Unknown Gain 3 Option 1 Gain 3 Option 2 Gain 3 Option 3 Lwn(555) Chl

42. Goddard Space Flight Center 42 Uncertainty in SeaWiFS Lwn Trends Oligotrophic Eutrophic Mesotrophic variation in retrieved nLw trend due to uncertainty in lunar-view to earth-view gain ratio at 765nm.

43. Goddard Space Flight Center 43 Known Issues: SeaWiFS Late-Mission SeaWiFS Lw(510) Anomaly

44. Goddard Space Flight Center 44 Removed Late-Mission Drift in SeaWiFS Before

45. Goddard Space Flight Center 45 Known Issues: MODISA Lw(412) Trend