Alaskan Stream Circulation and Exchanges through the Aleutian Island Passes: 1979-2003 Model Results
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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The objective of this research is to examine the long-term variability in the flow of the Alaskan Stream, as well as the northward transport through three selected Aleutian Island passes. Taking into consideration that upper ocean water properties and in part circulation in the Bering Sea are derived from northward flow through the Aleutians, it is important to understand how different anomalies in the movement of the Alaskan Stream might alter this communication with the Bering Sea. In the past, observational data has frequently underestimated the strength of the Alaskan Stream, basing measurements of geostrophic velocity on levels of no motion at either 1000 m or 1500 m. Using a 25-year 1979-2003 ice-ocean model the results presented in this study indicate that the Alaskan Stream transport is not only significantly larger than previously reported, but that westward flow extends to depths 4000 m. Research has also been conducted on the magnitude and frequency of eddy-induced changes to the path and strength of the Alaskan Stream. These changes can significantly impact northward flow through the Aleutian passes. This region is also of particular interest to the U.S. military. As recent observational and model studies have predicted future reductions of sea-ice in the Arctic, foreign military traffic might increase through the North Pacific Ocean, specifically the Aleutian Island passes, as countries begin to explore and conduct exercises within the Arctic region. This would increase the importance of understanding of acoustic properties within the Aleutian Island region, which is of relevance to Undersea Warfare.
- Physical and Dynamic Oceanography