A vorticity-based analysis of the spatial and temporal characteristics of the Beaufort Anticyclone

• Main Author: Gleicher, Kirstin J.
• Other Authors: Walsh, John E.
• Language: English
• Published: 2010
• Subjects: Beaufort Anticyclone; Arctic; Arctic Ocean; Pacific; Sea ice; Alaska; Siberia
• Online Access: http://hdl.handle.net/2142/18610

The Beaufort Anticyclone is the dominate pressure feature over the Arctic Ocean in all seasons and has a large influence on the surface wind regime and sea-ice motion. Sea level pressure (SLP) from the NCAR/NCEP Reanalysis is used to create a vorticity metric to investigate the spatial and temporal characteristics of the Beaufort Anticyclone from 1948-2008. Vorticity averaged over the Beaufort Anticyclone region correlated with Northern Hemisphere SLP show areas of strongest relationship south of Alaska and north of Siberia. These two areas are also present in SLP composite maps created using the vorticity timeseries. The spatial characteristics are investigated further by creating a timeseries of rapid change events. SLP maps of these events reveal similar features south of Alaska and north of Siberia. Temporal characteristics are investigated using running means and spectral analysis, which show an annual cycle. Teleconnection patterns have been shown to have an influence over the Arctic. The Beaufort Anticyclone vorticity metric is correlated with teleconnection index values; the Pacific Ocean patterns show a larger influence than the Atlantic patterns, contrary to past studies that show the Arctic Oscillation as a main driver over the Arctic. A significant correlation is found with the Pacific North American pattern in all seasons except summer. The El Niño Southern Oscillation shows a significant correlation in winter, and the Pacific Decadal Oscillation shows a significant correlation in winter and spring.