8 January 2007

1. From Missions to Measurements:an Ocean Color Experience 8 January 2007

2. NASA’s Goal To make available the highest quality ocean color (and sst) data to the broadest user community in the most timely and efficient manner possible.

3. Discipline Processing Rationale Distributed Science-led Geophysical Product Generation/Support • Uses/requires existing expertise and infrastructure - Minimizes expense & start-up time • Allows handling of multiple data sets simultaneously - Not limited to mission-specific requirements and objectives • Provides flexibility to support discipline science requirements - Products, algorithms, formats, gridding, reprocessings, etc. • Facilitates strong link between flight projects & science community

4. MODIS Ocean Processing Reorganization • MODIS Ocean Color processing reorganized by NASA HQ to coincide with new MODIS Ocean Science Team selection. • Ocean color to lead the NASA Earth Science Enterprise transition to “discipline processing”, i.e., move from “missions to measurements” processing. • Operational ocean color data processing transferred from MODAPS to the Ocean Color Discipline Processing Group on February 1, 2004 with Sea Surface Temperature following in 2005 • Data archive/distribution functions transferred from EOSDIS to Discipline group during active life of mission

5. GSFC Ocean Color Program Background:A Long History of Achievement • Nimbus-7 Coastal Zone Color Scanner (1978-1986) • Airborne Oceanographic Lidar (mid-1970’s-present) • Community Processing & Analysis Software • SEAPAK (1982-1991); SeaDAS (1991- present) • Nimbus-7/Coastal Zone Color Scanner Global Reprocessing (1985-2000) • MODIS & MODIS Ocean Team (1989-present) • SeaWiFS Project (1991-present) • Sensor Intercomparison & Merger for Biological & Interdisciplinary Ocean Studies Project (SIMBIOS; 1996-2003) • Ocean Color Climate Data Record (CDR) Development (REASoN-CAN; recent selection) • NASA NPP Science Team (VIIRS ocean color, recent selection) • Designated as NASA’s Ocean Color Discipline Group and assumed responsibility for MODIS Ocean Color Processing (Feb. 1, 2004), SST (August 2005) and NPP/VIIRS & Aquarius role

6. MODIS OC Processing Strategy • Initial focus on MODIS/Aqua • MODIS/Aqua more stable than MODIS/Terra • MODIS/Aqua more likely to overlap with NPP/VIIRS • Initial emphasis on calibration & Lwn’s* • Large seasonal/regional differences between MODIS/(Terra & Aqua) & SeaWiFS Lwn’s • Reduced product set until radiometry verified • Simplify processing for radiometry evaluations • Maintain a baseline consistent with SeaWiFS product suite. Expand product suite later with Community input/feedback * Lwn’s = Water-Leaving Radiances

7. MODIS Ocean Color Parameters • Current OC “Baseline” Parameter Set • Normalized water-leaving radiances (6) • Aerosol optical thickness • Atmospheric correction epsilon • Ångström exponent • Chlorophyll-a (1) • Diffuse attenuation coefficient at 490 nm • SST (day/night) • Same masks & flags as OC products • Recently added Chlorophyll fluorescence line height and Calcite concentration • Previous OC Parameter Set • Normalized water-leaving radiances (7) • Aerosol optical thickness (865 nm) • Atmospheric correction epsilon • Aerosol model numbers (2) • Clear water aerosol correction epsilon • CZCS pigment concentration • Chlorophyll-a concentration (3) • Total pigment concentration • Chlorophyll fluorescence line height • Chlorophyll fluorescence baseline • Chlorophyll fluorescence efficiency • Total suspended matter • Coccolithophore pigment concentration • Detached coccolithophore concentration • Calcite concentration • Diffuse attenuation at 490 nm • Phycoerythobilin concentration • Phycourobilin concentration • Instantaneous PAR • Instantaneous absorbed radiation for fluorescence • Gelbstoff absorption coefficient at 400 nm • Phytoplankton absorption coefficient at 675 nm • Total absorption coefficients (5) • Primary production (2 at Level-4)

8. Calibration/Validation Approach • Apply same cal/val approach as for SeaWiFS • Common processing codes • Work sensor calibration issues with MCST • Solar and lunar calibration analysis and products, e.g., calibration tables, response-vs-scan (RVS), sensor polarization. • Systematically test algorithms using both SeaWiFS & MODIS for comparison • Polarization, BRDF, glint, cloud masking, etc. • Global time series with regional analyses (clear-water, deep-water, coastal, basin-latitude zones)

9. Requirements for Success • Expertise:

10. Requirements for Success • Expertise: internal • highly integrated project structure with all elements co-located - continuous communication.

11. Requirements for Success • Expertise: internal and external • highly integrated project structure with all elements co-located - continuous communication. • Strong links with mission-specific expertise (MCST) and research community (algorithms, validation data, new products)

12. Requirements for Success • Expertise • Infrastructure • flexible data processing system that constantly upgrades procedures, technologies and equipment

13. Requirements for Success • Expertise • Infrastructure • flexible data processing system that constantly upgrades procedures, technologies and equipment SCIENCE drives the system rather than the SYSTEM driving the science

14. Current Capabilities Fully automated, distributed data system for acquiring, processing, analyzing, archiving, and distributing scientific data Current system supporting SeaWiFS, MODIS, MOS, OCTS, CZCS, and NPP (future) Approximately 40 distributed multiprocessor Linux PC’s with 300 terabytes of online storage shared by all project components including web/ftp-based data distribution system. processing rate for SeaWiFS global data currently at 4000x and MODIS/Aqua 150x

15. Requirements for Success • Expertise • Infrastructure • Data • Most efficient and ultimately most cost effective when source data is available online for all needs including processing, reprocessing, evaluation testing, distribution.

16. Requirements for Success • Expertise • Infrastructure • Data • Communication - Open and Continuous

17. OceanColor Web oceancolor.gsfc.nasa.gov Consolidated data access, information, services and community feedback

18. OceanColor Web oceancolor.gsfc.nasa.gov Consolidated data access, information, services and community feedback

25. Requirements for Success • Expertise • Infrastructure • Data • Communication - Open and Continuous • Intuitive and efficient data distribution

42. Evaluation Products The table below shows the increase in coverage over the single mission product realized through the merging of the Aqua and SeaWiFS data sets. Day % increase over SeaWiFS = 52.8617 % increase over MODIS   = 60.0602 8-Day % increase over SeaWiFS = 20.5960 % increase over MODIS   = 24.0016 Month % increase over SeaWiFS = 4.68613 % increase over MODIS   = 5.10188 Year % increase over SeaWiFS = 0.902050 % increase over MODIS   = 0.856695

49. Requirements for Success • Expertise: internal and external • Infrastructure • Data • Communication - Open and Continuous • Intuitive and Efficient data distribution • Community access to data processing/analysis tools