NOAA WP-3D Research Aircraft Investigates the
Bio-Physical Environment of the Bering Sea

A field project over the southeast Bering Sea using a NOAA WP-3D research aircraft and the NOAA ship Miller Freeman was conducted from April 23 through May 9, 1996 as part of the Fisheries-Oceanography Coordinated Investigations (FOCI) and the Coastal Ocean Program. The project documented the spatial and temporal evolution of phytoplankton concentration during the spring bloom in the Bering Sea, and how this concentration is related to the ocean's physical characteristics.

The preliminary results show higher phytoplankton concentrations where the sea ice is melting in the northern portion of the domain, and a prominent 100 by 200 km patch southeast of the Pribilof Islands with concentrations on the order of ten times background levels. This patch is in a region that has been found to feature a large spawning population of walleye pollock.

>Phytoplankton concentration was estimated from the P-3 using remote color- sensing instrumentation designed to detect upwelling radiance from the ocean; the ocean's physical characteristics were assessed using air- expendable bathythermographs and observations by moored buoys and the Miller Freeman. The aircraft was a highly effective oceanographic platform; its ability to fly under the persistent clouds of the Bering Sea allowed a view of the surface not generally possible from satellite, and its speed and logistical flexibility provided much better coverage than possible from a ship.<

Flight track of P-3 aircraft and surface chlorophyll concentrations for 9 May 1996.

Surface chlorophyll concentrations estimated remotely from color-sensing instrumentation aboard a NOAA P-3 during the flight of 9 May 1996. The oval patch in green signifies surface chlorophyll concentrations of ~10 milligrams/m3; the surrounding areas in blue indicate concentrations of ~1 milligrams/m3. The flight track of the P-3 is shown with a solid black line. Vertical profiles of ocean temperature from air-expendable bathythermographs were collected at the X's. The open circles indicate the positions of the moored meteorological/oceanographic buoys.