Approach for the long-term spatial and temporal evaluation of ocean color satellite data products in a coastal environment

Ocean color satellites provide a mechanism for studying the marine biosphere on temporal and spatial scalesotherwise unattainable via conventional in situ sampling methods. These satellites measure visible and infraredradiances, which are used to estimate additional geophysical data products, such as the concentration of thephytoplankton pigment chlorophyll a, C a , via the application of secondary bio-optical algorithms. The op-erational C a algorithms for the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and Moderate ResolutionImaging Spectroradiometer (MODIS), for example, perform well in the global open ocean, but often degradein more optically complex coastal environments where global parameterizations are less applicable. Organiza-tions such as the Chesapeake Bay Program, which have interest in using SeaWiFS and MODIS data productsto facilitate regional monitoring activities, must rely on locally parameterized algorithms to achieve requisiteaccuracies. To facilitate algorithm selection, the NASA Ocean Biology Processing Group recently developed theinfrastructure to spatially and temporally evaluate a long-term regional time-series of satellite observations usingin situ measurements as ground-truth. Here, we present this approach using a case study in the Chesapeake Bay,where a series of C