Planktonic Ecosystem Response to Changing Sea Ice and Upper Ocean Physics in the Chukchi and Beaufort Seas: Modeling, Satellite and In Situ Observations

We propose a study of the historical, contemporary, and future changes of the Chukchi and Beaufort marine planktonic ecosystem in response to changes in the sea ice cover and the upper ocean physics. Our scientific objectives are to:

1) Synthesize the historical evolution of the biology-ice-ocean system in the Chukchi and Beaufort seas from 1978 to the present through modeling and analyses of satellite and in situ observations; quantify and understand the large-scale changes that have occurred in the sea ice, upper ocean, and marine planktonic ecosystem over the shelves and the basin.
2) Identify key linkages and interactions between the sea ice, upper ocean, and planktonic ecosystem to understand how changes in sea ice, water temperature, vertical mixing, and upper ocean stratification affect light availability, nutrient distribution, biogeochemical processes, food-web dynamics, and the strength of benthic-pelagic coupling.
3) Examine how the Chukchi/Beaufort planktonic ecosystem responds to changes in nutrient-rich Pacific water inflow at Bering Strait and advection on the shelves, in the Beaufort shelfbreak jet, and in mesoscale physical processes that enhance shelf-basin exchange such as eddy and filament formation and shelf-break upwelling.
4) Explore the impacts of projected future anthropogenic global climate change (including a summer arctic ice-free regime) on the Chukchi/Beaufort ecosystem.

To achieve these goals we will conduct observational analyses using satellite ocean color, sea ice, sea surface temperature (SST), and sea surface salinity data, and in situ data. We will also develop a fully coupled 3D high-resolution Biology/Ice/Ocean Modeling and Assimilation System (BIOMAS) for synthesis and modeling of the Chukchi and Beaufort seas. BIOMAS will combine advanced sea ice and ocean models with a tested arctic marine planktonic ecosystem model and assimilate satellite sea ice concentration and SST. SeaWiFS/MODIS-derived chlorophyll and primary productivity and in situ biophysical data will be used for model calibration/validation. This unique system will enhance our understanding of how the planktonic ecosystem responds to changing sea ice and upper ocean physics in the Chukchi and Beaufort seas.

Relevance to this NRA. This proposal responds to the Ocean Biology & Biogeochemistry program and it directly addresses the first research theme: How are ocean ecosystems and the biodiversity they support influenced by climate and environmental variability and change, and how will these changes occur over time? By exploring the central science question of “What is the impact of climate change (natural and anthropogenic) on the biogeochemistry and ecology of the Chukchi and Beaufort seas?” it responds specifically to sub-element topic 2.1.2: Beaufort/Chukchi Seas Data Synthesis, Assimilation, and Modeling Program. It is also relevant to element topic 2.2: Biological and Biogeochemical Impacts of Melting Ice in the Beaufort and Chukchi Seas.