Changing Seasonality of the Arctic: Alteration of Production Cycles and Trophic Linkages in Response to Changes in Sea Ice and Upper Ocean Physics

Significant changes in the arctic environment have been detected in recent years. One of the most striking changes is the decline of arctic sea ice. A diminished arctic ice cover may have a profound effect on all components of the marine ecosystem. Despite the extreme polar conditions, the Arctic Ocean supports a complex pelagic food web that includes zooplankton, fish, birds, seals, walruses, whales and the top predator, the polar bear. At the base of the food chain, supporting all the marine life, are the phytoplankton and algae that produce organic carbon. The central hypothesis of this collaborative research is that reduction in ice cover and the concomitant upper ocean physical changes in response to climate warming will substantially modify and impact the seasonality of the Arctic planktonic marine ecosystem by altering the timing, magnitude, duration, and pattern of production cycles, with effects including changes in primary production, in utilization and cycling of organic carbon, in ecosystem function, and in the relative proportions of biomass in the different ecosystem components. To address this overarching hypothesis, we plan to synthesize model estimates and available field observations retrospectively and predicatively. The model to be developed is a coupled pan-Arctic Biology/Ice/Ocean Modeling and Assimilation System (BIOMAS) that aims at an integrated understanding of three components of the arctic system: sea ice, ocean, and the planktonic ecosystem.