The Arctic Oscillation and Wintertime Climatology of the Midwest and Tennessee Valley Regions of the USA (1951-2010)

An analysis was conducted to assess the relationship between the Arctic Oscillation (AO) and wintertime climatology of the Midwest and Tennessee Valley regions of the USA. In particular, this study focuses on variation in wintertime temperatures and snowfall totals during the top ten most positive and negative AO winters for the aforementioned regions. In addition, NCEP/NCAR reanalysis composite maps were created and examined to evaluate the relationship between certain atmospheric parameters and the opposing phases of the AO. In the Midwest and Tennessee Valley regions, variation in wintertime mean temperature and snowfall totals are associated with strong phases of the AO. The top ten most negative AO winters resulted in below average temperatures and above average snowfall totals. In contrast, the top ten most positive AO winters resulted in above average temperatures and below average snowfall totals. In addition, variation in mean wintertime temperature and snowfall totals is less significant during positive AO winters in comparison to negative AO winters. The top 10 most positive and negative AO winters appear to provide a significant link between anomalous middle and upper atmospheric circulation and atypical surface weather patterns across the Midwest and Tennessee Valley regions.