circulation patterns in the region; understand seasonally changing ocean stratification and how this impacts current systems; and understand processes that transport water between the Chukchi and Beaufort Seas (primarily winds and unstable flow patterns that generate ocean eddies).
The Beaufort/Chukchi Seas Mesoscale Meteorology Modeling Study26 is also funded by BOEM. Wind forcing, the main driver of surface ocean currents and sea ice motion, and weather patterns in the Beaufort and Chukchi Seas are being monitored, analyzed, and modeled numerically to evaluate and predict oil spill trajectories and assess potential environmental impacts. Local weather systems and winds are complicated in the Beaufort Sea region because of temperature differences between the land and ocean and the steep terrain changes associated with the Brooks Range to the south. Meteorological buoys are being deployed in the Chukchi Sea, atmospheric data are being assimilated into meteorological models, and the mechanisms leading to the formation and dynamics of local weather systems are being investigated.
BOEM’s oil spill risk analysis model generates an ensemble of many simulated oil spill trajectories over many years of wind and ocean current data to develop statistics about the risks of an oil spill.27 Numerical trajectory models estimate trajectories based on velocity data from observations or circulation models; they do not directly assimilate oceanographic or meteorological data, but rely on the degree to which the data represent real-world conditions. For example, as discussed earlier in this chapter, the surface ocean flow over the Chukchi shelf is often not in the direction of the wind because the flow from the Pacific to the Arctic basins is largely driven by the ocean pressure gradient between the two basins. Because surface trajectory models are often forced only by winds or by ocean climatology that is not valid during the time of interest, this key feature of ocean dynamics is not represented. Further significant efforts on model improvement and validation are needed. A BOEM-funded dedicated tracer-release study to examine dispersion in the Chukchi Sea is being planned by researchers at BOEM and the University of Alaska, Fairbanks; this will be interfaced with modeling efforts of NOAA and BSEE.
The Office of Naval Research recently initiated two projects (Emerging Dynamics of the Marginal Ice Zone28 and Sea State and Boundary Layer Physics of the Emerging Arctic Ocean29) to study the retreat of sea ice in the Beaufort Sea and the physical mechanisms in the marginal ice zone. An important part of these studies is wave-ice interaction; wave buoys and ice-mounted instruments are being used to measure ice thickness and atmospheric and oceanic parameters.
In addition to these programs, the European Commission funds basinwide Arctic projects. Current examples are Arctic Climate Change, Economy and Society,30 which runs from 2011 to 2014, and Ice, Climate, Economics—Arctic Research on Change,31 which runs from 2014 to 2017. Both have observational and modeling components but also include impacts from oil spills in ice.