Shelfbreak circulation in the Alaskan Beaufort Sea: Mean structure and variability

Historical hydrographic and current meter data are used to investigate the properties and circulation at the shelf edge of the Alaskan Beaufort Sea. Thirty‐three individual cross‐sections, spanning the time period 1950 to 1987, are combined in a topographical framework to produce mean vertical hydrographic sections, as well as a section of mean absolute geostrophic velocity referenced using the current meter data. This reveals the presence of a narrow (order 20 km) eastward current, referred to as the Beaufort shelfbreak jet. The jet has three distinct seasonal configurations: In late‐spring to late‐summer, cold, winter‐transformed Bering water is advected in a subsurface current; from mid‐summer to early fall a surface intensified current advects predominantly Bering summer water; and from mid‐fall to mid‐spring, under easterly winds, the jet transports upwelled Atlantic water. The volume transport of the jet represents a significant fraction of the inflowing transport through Bering Strait. While the characteristics and flow of the winter‐transformed Bering water vary interannually, this water mass ventilates predominantly the upper halocline.