A Modeling Study of Primary Production and Carbon Flux in West Antarctic Peninsula Continental Shelf Waters

Hae-Cheol Kim, Eileen E. Hofmann, and Barbara B. Prézelin

This study presents results from models that are designed to simulate the underwater light field, to simulate phytoplankton primary production, and to estimate the fate of phytoplankton carbon in continental shelf waters of the west Antarctic Peninsula (WAP). The fate of newly-produced phytoplankton carbon obtained from simulations for the WAP was investigated using budget calculations that included the effects of grazing, advection, and sinking. For the western Antarctic Peninsula region, horizontal (across-shelf component) advection is the dominant process controlling primary production carbon in the outer-shelf areas in all seasons. Depending on season, advection can remove up to 34% of the phytoplankton carbon in the shelf waters. Grazing, however, is as important as across-shelf advection during the summer and can be an order of magnitude greater in inner-shelf waters than in mid- and outer-shelf waters. Sinking is also a dominant process that can remove up to 6% of primary production carbon. The results of carbon budgets show that advective processes provide a dominant control on the fate of primary production, which suggests that primary production estimates for Antarctic coastal waters should be based on observational studies or models that incorporate circulation as well as biological processes.

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