Alaska Winter Temperatures and Teleconnections

Reader Gary posed a question regarding the relationship between wintertime freezing temperatures and teleconnection indices. Fortunately, the ESRL reanalysis site has a very handy tool for correlating temperatures or other atmospheric variables to a variety of teleconnection indices. Frankly, there are a number of indices that I have never heard of. Nevertheless, I spent about 15 minutes systematically going through each index and generating a map of the correlation between the index value and October-March surface temperatures in Alaska between 1948 and 2014. Only 'interesting' ones were included. For reference, a correlation of +1.0 indicates a perfect positive relationship and a correlation of -1.0 indicates a perfect negative (or inverse) relationship. This is the same as Pearson's "R".

The rest of the blog post is the series of maps. Since there are so many I am not going to add a figure caption to each one at this time. The automatically generated legend tells which index was used. Also, the name of the index is pretty cryptic in many instances so here is the link to the page with a description of each index: http://www.esrl.noaa.gov/psd/data/climateindices/list/

One final note, there is a difference between causation and correlation. Just because something is correlated, doesn't necessarily mean there is a cause and effect relationship (e.g., the strong negative correlation between Alaska winter temperatures and the Antarctic Oscillation). Also, there is a lot of co-variance between data. For example, the PDO index is largely reflective of North Pacific sea surface temperatures. Therefore, it is not surprising that a large pool of warm air sitting right next to Alaska will cause Alaska temperatures to be warmer than normal.