Figure 4. Left panel: Satellite surface Chlorophyll a concentration overlaid with a web-based oceanographic model showing surface current vectors (larger arrows indicate stronger currents). Chlorophyll a is a measure of the pigment concentration generated from phytoplankton, which indicates how much primary production is taking place in the water and is a sign of how nutrient rich the water is. High levels of Chlorophyll a in offshore waters indicates a strong freshwater outflow from rivers into the ocean and strong southeast currents act to move that freshwater offshore. The pink circle near 28.8N and 87.2W was the initial sampling location of the thick fresher surface layers. Right panel: Surface current vectors measured from the ship’s acoustic Doppler current profiler (ADCP) with surface water temperature (vector color) indicating the speed (vector size) and direction (vector angle) of water movement. Both the oceanographic model output (left) and ADCP surface currents confirm transport of Mississippi freshwater offshore and to the southeast.
Surface Chlorophyll and Current Vectors
Image courtesy of Left panel: Image courtesy of USF College of Marine Science Optical Oceanography Lab; Right panel: Image courtesy of Exploring Migrating Deep-Sea Scattering Layers. Download largest version (jpg, 78 KB).

Figure 4. Left panel: Satellite surface Chlorophyll a concentration overlaid with a web-based oceanographic model showing surface current vectors (larger arrows indicate stronger currents). Chlorophyll a is a measure of the pigment concentration generated from phytoplankton, which indicates how much primary production is taking place in the water and is a sign of how nutrient rich the water is. High levels of Chlorophyll a in offshore waters indicates a strong freshwater outflow from rivers into the ocean and strong southeast currents act to move that freshwater offshore. The pink circle near 28.8N and 87.2W was the initial sampling location of the thick fresher surface layers. Right panel: Surface current vectors measured from the ship’s acoustic Doppler current profiler (ADCP) with surface water temperature (vector color) indicating the speed (vector size) and direction (vector angle) of water movement. Both the oceanographic model output (left) and ADCP surface currents confirm transport of Mississippi freshwater offshore and to the southeast.

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