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Ocean color and SST data product validation. NASA Ocean Biology Processing Group Goddard Space Flight Center, Greenbelt, Maryland, USA SeaDAS Training Material. Ocean color level-2 match-ups using SeaBASS data. SeaWiFS Sept 1997 - Present. MODIS-Aqua July 2002 - Present.
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Ocean color and SST data product validation NASA Ocean Biology Processing Group Goddard Space Flight Center, Greenbelt, Maryland, USA SeaDAS Training Material SeaDAS Training ~ NASA Ocean Biology Processing Group
Ocean color level-2 match-ups using SeaBASS data SeaWiFSSept 1997 - Present MODIS-AquaJuly 2002 - Present color key: valid matchexcluded “match-up” defined as: (1) in situ measurement collected within +/- 3 hours of satellite overpass (2) 5x5 satellite pixel box centered on in situ lat/lon target (3) homogeneity and sensor/solar geometry tests applied (4) filtered median of valid (non-flagged) pixels, if >50% remain SeaDAS Training ~ NASA Ocean Biology Processing Group
Comparison of coincident satellite and in situ nLw() MODIS-Aqua SeaWiFS SeaDAS Training ~ NASA Ocean Biology Processing Group
Comparison of coincident satellite and in situ Chl MODIS-Aqua SeaWiFS Bailey and Werdell, Rem. Sens. Environ.102, 12-23 (2006) http://seabass.gsfc.nasa.gov/matchup_results.html SeaDAS Training ~ NASA Ocean Biology Processing Group
Ocean color level-3 validation • Level-2 match-ups are sparse and do not provide detailed temporal (e.g., seasonal) or spatial (e.g., latitudinal, along scan, across detectors) statistics. • Level-3 sensor-to-sensor comparisons provide some insight into such temporal and spatial behavior. • Data are prepared by … • binning globally at selected spatial resolution (4.6 or 9-km) • binned at equal time intervals (4- or 8-days from the start of each consecutive 32-day period) • identifying common bins for both sensors Chl, 9-km 8-day common deep-water bins April-2006 MODIS-Aqua SeaWiFS 0.01 mg m-3 1 mg m-3 SeaDAS Training ~ NASA Ocean Biology Processing Group
Definition of Level-3 trophic subsets deep water (depth > 1000 m) oligotrophic (Chl < 0.1 mg m-3) eutrophic (1 < Chl < 10 mg m-3) mesotrophic (0.1 < Chl < 1 mg m-3) SeaDAS Training ~ NASA Ocean Biology Processing Group
nLw() temporal trends deep water, 4-day composites MODIS-Aqua SeaWiFS 412 nm 412 nm 443 nm 443 nm 488 nm 490 nm 510 nm 531 nm 555 nm 551 nm 1998 2006 2003 2006 SeaDAS Training ~ NASA Ocean Biology Processing Group
Comparison of relative temporal stability of nLw() deep water, 4-day composites, common bins MODIS-Aqua SeaWiFS SeaDAS Training ~ NASA Ocean Biology Processing Group
MODIS-Aqua / SeaWiFS ratio trends oligotrophic mesotrophic eutrophic nLw() ratios Chl ratios SeaDAS Training ~ NASA Ocean Biology Processing Group
oligotrophic mesotrophic eutrophic Comparison of spectral distribution trends MODIS-Aqua & SeaWiFS mean nLw() SeaDAS Training ~ NASA Ocean Biology Processing Group
Seasonal Chl images MODIS-Aqua SeaWiFS Winter 2004 Winter 2004 Summer 2004 Summer 2004 • 0.01-64 mg m-3 SeaDAS Training ~ NASA Ocean Biology Processing Group
SST validation buoy measurements SeaDAS Training ~ NASA Ocean Biology Processing Group
References Ocean color level-2 match-ups http://seabass.gsfc.nasa.gov/matchup_results.html S.W. Bailey and P.J. Werdell, Rem. Sens. Environ.102, 12-23 (2006) Ocean color level-3 validation B.A. Franz et al., Proc. SPIE 5882, 304-316 (2005) SST validation and match-up database K.A. Kilpatrick et al., J. Geophys. Res. 106, 9179-9197 (2001) SeaDAS Training ~ NASA Ocean Biology Processing Group
