Abstracts

The Beaufort Anticyclone and its Role in the Climate System

Kirstin J. Gleicher¹, John E. Walsh², William L. Chapman^3
1Department of Atmospheric Sciences, University of Illinois, 105 South Gregory Street, Urbana, IL, 61801, USA, gleiche1@illinois.edu
²International Arctic Research Center (IARC), University of Alaska Fairbanks, PO Box 757340, Fairbanks, AK, 99775, USA
³215 Atmospheric Sciences Building, MC 223, Urbana, IL, USA

We aim to better characterize the Beaufort Anticyclone in terms of its spatial and temporal variability. The Beaufort Anticyclone plays an important role in arctic sea ice and ocean dynamics, and there have been few studies focused on this feature. In order to track the magnitude of circulation over the Beaufort Sea, a vorticity metric is calculated directly from the National Centers for Environmental Prediction (NCEP) reanalysis sea-level pressure (SLP) fields from 1948 to 2008. For the spatial significance, calculated vorticity is correlated with the SLP for 90°N-20°N. Significant correlations show a strong opposite signal located over the Aleutian Low track in the Northern Pacific and over Northern Siberia, and show no correlation with the Arctic Oscillation node near Iceland. The corresponding NCEP reanalysis monthly SLP maps are used to create composite differences based on extreme states of the Beaufort Anticyclone. Composite differences show large SLP differences over similar regions as the correlated vorticity plots. The calculated vorticity values are also plotted in timeseries. These timeseries show relatively positive vorticity anomalies in the first 20 years, through 1968, followed by relatively negative years through the 1980s and returning to positive through 2008. The results of this study have important implications for sea ice transport and mass flux connections between the middle-latitudes and the Arctic over a spectrum of timescales.

Abstract Categories: 1.1 Advances in Understanding Arctic System Components