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Chesapeake Bay as observed by SeaWiFS and MODIS-Aqua


Chesapeake Bay, one of the largest and most productive estuaries in North America, suffers from persistent eutrophication as a result of excessive anthropogentic nutrient loads entering its watershed [1,2]. As such, federal, state, and other regional organizations routinely monitor Bay water quality via a series of shipboard hydrographic sampling programs [3]. After discussion with participants in the 2006 Chesapeake Bay Remote Sensing Symposium, the NASA Ocean Biology Processing Group (OBPG) initiated an effort exploring how satellite observations of ocean color might be incorporated into such monitoring and regulatory activities as a complementary data source. The temporal resolution and spatial coverage provided by SeaWiFS and MODIS-Aqua, for example, far exceed that of conventional in situ sampling programs, yet their Chesapeake Bay time-series are currently underutilized with regards to water quality monitoring.

The OBPG effort commenced with a chlorophyll algorithm round robin, in collaboration with the Chesapeake Bay Program (CBP), NOAA, Old Dominion University, and the University of Maryland. The mission-long SeaWiFS and MODIS-Aqua Bay time-series were repeatedly processed using contributed algorithms, then vetted using the CBP Water Quality Monitoring data set (49 mainstem Bay stations revisited monthly from 1984 to 2005) provided to the OBPG by the Maryland Department of Natural Resources. The NOAA CoastWatch East Coast Node currently produces daily SeaWiFS chlorophyll maps of the Bay based on preliminary recommendations from this activity. The OBPG later expanded the scope of this effort by extending MODIS-Aqua processing to include its land and cloud bands (increased spatial resolution compared to the ocean bands), by evaluating an alternative MODIS-Aqua atmospheric correction approach [4], and by exploring how in situ measurements of atmospheric parameters improve SeaWiFS and MODIS-Aqua atmospheric correction over the Bay. Below, we present a catolog of the OBPG analyses, documents, and presentations prepared to date.



Online analyses and documentation

Regional trends in Level-2 ocean color data products
Chesapeake Bay ocean color chlorophyll algorithm round robin, Round 2
Chesapeake Bay ocean color chlorophyll algorithm round robin, Round 1, which led to:
NOAA CoastWatch East Code Node Chesapeake Bay SeaWiFS chlorophyll-a
Extension of MODIS ocean processing capabilities to include the 250 and 500-meter land/cloud bands
MODIS-Aqua and SeaWiFS AOT comparisons with Chesapeake Bay CIMELs (PART TWO)
MODIS-Aqua and SeaWiFS AOT comparisons with Chesapeake Bay CIMELs (PART ONE)
Mid-Atlantic Bight aerosol analyses for ocean color applications

Publications and proceedings

P.J. Werdell, S.W. Bailey, B.A. Franz, L.W. Harding Jr., G.C. Feldman, and C.R. McClain, Regional and seasonal variability of chlorophyll-a in Chesapeake Bay as observed by SeaWiFS and MODIS-Aqua, Remote Sensing of Environment 113, 1319-1330 (2009).
P.J. Werdell, B.A. Franz, S.W. Bailey, L.W. Harding Jr., and G.C. Feldman, Approach for the long-term spatial and temporal evaluation of ocean color satellite data products in a coastal environment, Proc. SPIE 6680, doi:10.1117/12.732489 (2007).
Z. Ahmad, C.R. McClain, J.R. Herman, B.A. Franz, E.J. Kwiatkowska, W.D. Robinson, E.J. Bucsela, and M. Tzortziou, Atmospheric correction for NO2 absorption in retrieving water-leaving reflectances from the SeaWiFS and MODIS measurements, Applied Optics 46, 6504-6512 (2007).
B.A. Franz, P.J. Werdell, G. Meister, E.J. Kwiatkowska, S.W. Bailey, Z. Ahmad, and C.R. McClain, MODIS land bands for ocean remote sensing applications, Proc. Ocean Optics XVIII, Montreal, Quebec, 16 pp. (2006).
S.R. Signorini, C.R. McClain, A. Mannino, and S.W. Bailey, Report on ocean color and carbon study for the South Atlantic Bight and Chesapeake Bay regions, NASA/TM-2005-212787, NASA Goddard Space Flight Center, Greenbelt, MD, 45 pp (2005).

Presentations

P.J. Werdell, The long-term spatial and temporal evaluation of ocean color data products in the Chesapeake Bay, NASA DEVELOP Internship Program student review, NASA Goddard Space Flight Center, Greenbelt, MD, 10 Oct 2007.
P.J. Werdell, B.A. Franz, S.W. Bailey, L.W. Harding Jr., and G.C. Feldman, Approach for the long-term spatial and temporal evaluation of ocean color satellite data products in a coastal environment, SPIE Optics + Photonics, Coastal Ocean Remote Sensing, San Diego, CA, 26 Aug 2007.
M. Szeto, Validating the GSM01 algorithm for chlorophyll products in the Chesapeake Bay, University of New Hampshire Research and Discover Summer Intern final presentation, NASA Goddard Space Flight Center, Greenbelt, MD, 9 Aug 2007.
P.J. Werdell, B.A. Franz, G.C. Feldman, and L.W. Harding Jr., Approach for the long-term spatial and temporal evaluation of ocean color data products in a coastal environment, NASA Ocean Color Research Team Meeting, Seattle, WA, 11 Apr 2007.
Z. Ahmad, E.J. Kwiatkowska, B.A. Franz, C.R. McClain, and B. Holben, Aerosol optical thickness from the SeaWiFS and MODIS sensors over the Chesapeake Bay, NASA Ocean Color Research Team Meeting, Seattle, WA, 11 Apr 2007.
B.A. Franz, P.J. Werdell, and G.C. Feldman, SeaWiFS and MODIS-Aqua Ca retrievals in Chesapeake Bay, Chesapeake Bay chlorophyll-a algorithm meeting, NOAA Chesapeake Bay Office, Annapolis, MD, 3 Apr 2007.
E.J. Kwiatkowska, Z. Ahmad, B.A. Franz, C.R. McClain, and B. Holben, Chesapeake Bay AOT comparisons between AERONET CIMEL measurements and ocean color products from MODIS-Aqua and SeaWiFS, NASA MODIS Science Team Meeting, Adelphi, MD, 31 Oct 2006.
P.J. Werdell, The Chesapeake Bay Program Ca algorithm round robin, Chesapeake Bay chlorophyll-a algorithm meeting, NOAA Chesapeake Bay Office, Annapolis, MD, 18 Jul 2006.