ocean color and sst data product validation
DESCRIPTION
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. - PowerPoint PPT PresentationTRANSCRIPT
SeaDAS Training ~ NASA Ocean Biology Processing Group
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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
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Ocean color level-2 match-ups using SeaBASS data
SeaWiFSSept 1997 - Present
MODIS-AquaJuly 2002 - Present
color key: valid match excluded
“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
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Comparison of coincident satellite and in situ nLw()
SeaWiFSMODIS-Aqua
Wavelength # Matches Mean Ratio* % Difference** r2
MODIS SeaWiFS MODIS SeaWiFS MODIS SeaWiFS MODIS SeaWiFS MODIS SeaWiFS
412 412 120 553 0.747 0.905 30.898 24.098 0.742 0.827443 443 133 702 0.862 0.915 18.811 17.480 0.815 0.830488 490 109 660 0.923 0.918 14.563 15.101 0.907 0.821531 510 32 479 0.933 0.918 11.178 13.739 0.934 0.849551 555 120 702 0.940 0.915 12.255 16.878 0.943 0.931667 670 107 666 0.682 0.920 36.392 45.717 0.735 0.876
SeaDAS Training ~ NASA Ocean Biology Processing Group
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Comparison of coincident satellite and in situ Chl
Sensor # Matches Mean Ratio % Diff r2
SeaWiFSMODIS/Aqua
1293263
0.9981.084
33.140.4
0.7960.780
SeaWiFSMODIS-Aqua
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
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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
SeaWiFSMODIS-Aqua
0.01 mg m-3 1 mg m-3
SeaDAS Training ~ NASA Ocean Biology Processing Group
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Definition of Level-3 trophic subsets
deep water (depth > 1000 m) oligotrophic (Chl < 0.1 mg m-3)
mesotrophic (0.1 < Chl < 1 mg m-3) eutrophic (1 < Chl < 10 mg m-3)
SeaDAS Training ~ NASA Ocean Biology Processing Group
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nLw() temporal trends
412 nm
443 nm
488 nm
531 nm
551 nm
412 nm
443 nm
490 nm
510 nm
555 nm
2003 2006 20061998
SeaWiFSMODIS-Aqua
deep water, 4-day composites
SeaDAS Training ~ NASA Ocean Biology Processing Group
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deep water, 4-day composites, common bins
Comparison of relative temporal stability of nLw()
MODIS-Aqua SeaWiFS
SeaDAS Training ~ NASA Ocean Biology Processing Group
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MODIS-Aqua / SeaWiFS ratio trends
oligotrophic mesotrophic eutrophic
Chl ratios
nLw() ratios
SeaDAS Training ~ NASA Ocean Biology Processing Group
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Comparison of spectral distribution trends
MODIS-Aqua & SeaWiFS mean nLw()
oligotrophicmesotrophiceutrophic
SeaDAS Training ~ NASA Ocean Biology Processing Group
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Seasonal Chl images
0.01-64 mg m-3
Summer 2004
Winter 2004
SeaWiFSMODIS-Aqua
Winter 2004
Summer 2004
SeaDAS Training ~ NASA Ocean Biology Processing Group
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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)