Low-salinity Pacific Water input at the Bering Strait is a major source of freshwater and nutrients to the Arctic Ocean. However, before reaching the deep basin, the Pacific Water can be modified in its transit across the shallow Chukchi Sea through air-sea interactions, mixing, and the freeze/melt ice cycle. Observations indicate that Pacific Water tends to follow one of three topographically-steered pathways through the Chukchi (shown schematically in Figure 1). At the northeast edge of the Chukchi, Barrow Canyon creates a region in which a substantial portion of the Pacific inflow is concentrated within 15-20 km of the coast in the form of the Alaskan Coastal Current, making it the ideal set-up for monitoring with an Autonomous Underwater Vehicle (AUV, see picture). The AUV undulates through the water column to within a few meters of the bottom and surface, acquiring temperature, salinity, pressure, velocity, backscatter, and fluorescence data. I am using this information to investigate the wind-driven response of the Alaskan Coastal Current. In particular, I am looking at how water mass properties and transports are influenced. The complexities of this region, set by the topography, coastline, and seasonal ice cover, offer a rich physical environment within which the flow dynamics may be controlled by a variety of three-dimensional processes, and interpreting the oceanic response to even simple forcing is difficult. I am hoping to extend this work using simple process-oriented models to try and better understand smaller-scale dynamics, including the propagation of shelf waves and inertial waves through the canyon, and their impact on cross-shelf circulation and mixing in this region.
Last updated: March 19, 2010