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SST is derived by compositing
data from three sources, the Advanced Very-High Resolution Radiometer
onboard the Polar Orbiting Environmental Satellite (AVHRR-POES),
MODIS Terra and MODIS Aqua, and represents the near-surface ocean
temperature, not the temperature of the entire water column.
Daily synoptic views of surface concentrations
of chlorophyll a are derived from the Sea-viewing Wide Field of
View Sensor (SeaWiFS) ocean color sensor onboard the SeaStar
spacecraft. Chlorophyll a is considered to be an index of the
amount of phytoplankton biomass present in surface water.
Zooplankton biomass is derived from shipboard
surveys of the U.S. Northeast Shelf ecosystem - these small animals
link the energy produced through primary production to higher
trophic levels. From 1977-1987, the MArine Resources Monitoring,
Assessment, & Prediction (MARMAP) program conducted intensive
surveys from Cape Hatteras, North Carolina to Nova Scotia. These
efforts continued at a reduced level through the 1990s and are
ongoing today. Currently, 30 plankton samples are taken 6 times
a year in each of the four ecosystem subareas: Mid-Atlantic Bight,
Southern New England, Georges Bank, and Gulf of Maine (resulting
in approximately 720 measures of zooplankton biomass annually).
Phytoplankton and zooplankton also are collected
on monthly transects across the Gulf of Maine and the Middle Atlantic
Bight using Ships of Opportunity. Phytoplankton abundance is quantified
based on the color of the sample. Zooplankton abundance is based
on counts of individual species and stages. During the spring
and summer of 2006, collections were suspended along the Middle
Atlantic Bight transect owing to lack of funding.
Long term SST were extracted from the
Extended Reconstructed Sea Surface Temperature (ERSST, version
2) dataset. This dataset is based on the temperature compilation
of the International Comprehensive Ocean-Atmosphere Data Set (ICOADS)
SST dataset and represents interpolation procedures that reconstructs
SST fields in regions with sparse data.
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