Bering Sea | Climate and Oceanography
Assimilation of continuous Bering Sea bottom temperature data into a regional circulation model Presenter: Albert Hermann , Albert.J.Hermann@noaa.gov Kelly Kearney , kelly.kearney@noaa.gov, Cooperative Institute for Climate, Ocean, and Ecosystem Studies Phyllis Stabeno , phyllis.stabeno@noaa.gov, NOAA Pacific Marine Environmental Laboratory
Calvin Mordy , calvin.w.mordy@noaa.gov, CICOES, University of Washington Shaun Bell , shaun.bell@noaa.gov, NOAA Pacific Marine Environmental Laboratory Thomas Van Pelt , thomas.vanpelt@noaa.gov, University of Washington CICOES
The Bering Sea supports major commercial fisheries including Pacific cod ( Gadus macrocephalus ) and walleye pollock ( Gadus chalcogrammus ), which are strongly influenced by the annual patterns of bottom temperatures. Detailed regional model hindcasts, driven by observed large-scale winds and ocean conditions, have been used to effectively capture the general observed patterns and interannual variability of summertime bottom temperatures. Model validation of the fall, winter, and spring conditions, however, has been limited to moored time series along the middle shelf and periodic research cruises, as synoptic temperature surveys across the Bering Sea shelf have been limited (indeed, nonexistent) during these times. Newly emerging continuous time series data derived from ~30 “popup” moorings deployed at multiple depths across most of the Bering Sea shelf during 2020-2022 are now being used to validate our hindcasts over the full year, and to reveal patterns of model bias. Persistent biases relative to data have underscored the potential for improved hindcasts through direct data assimilation. Here we describe initial hindcast model results which explicitly assimilate this new popup dataset, using a simplified form of Ensemble Kalman Filtering. We expect the resulting hindcast improvements to support better understanding of bottom temperatures dynamics over the whole Bering Sea region. The assimilation results we describe may also set the stage for future efforts to better predict bottom temperatures in near-real time, which would strengthen conservation and management of fish and other resources of economic and community importance in the Bering Sea.
Alaska Marine Science Symposium 2023 38
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