VARIATIONS OF PRIMARY PRODUCTION IN THE SOUTHERN CHUKCHI SEA ESTIMATED FROM SATELLITES IMAGES

Abstract

Bering Strait/Chukchi Sea is the only conduit of water masses and organic matter between the North Pacific and Arctic Oceans. The quantity of nutrients and organic matter flowing through this major passage into the Chukchi Sea and subsequently into the Arctic Ocean must be determined to understand the present functioning of the Arctic system, especially related to production and biogeochemical processes. Because of the logistic problems such as ice cover and political issues, recently there have been not many biochemical studies, especially for seasonal and annual time series in the regions. Based on the in situ measurements for chlorophyll-a and carbon uptake rates of phytoplankton in 2003-2004, the seasonal and annual variations of primary production in the regions were estimated from the satellite ocean color images (MODIS) during the recent period from 2002-2006. Generally, seasonal and annual variations of primary production and chlorophyll were stronger in the western side than in the eastern side of the Bering Strait. The estimated values of primary production in the eastern side of the Bering Strait was much higher in this study than those of in situ measurements which is believed to the effects of inorganic particles in the water column discharged from rivers and coastal areas in Alaska or suspended particles from sediments on seafloor because of a shallow water depth <30 m in this area. The area and intensity of the production in the central Chukchi Sea as a hot spot were largest and highest in August based on averages from 2002-2006.