Sunday, August 24, 2014

Recent Arctic Sea Ice Records Suggest Another Frigid Winter Ahead

This is a follow-up post to the sea ice publication yesterday.

An examination of recent sea ice levels and their corresponding winter temperature anomalies indicates the winter of 2014-2015 may very well be heading down a colder than normal path this season.

Click to enlarge
The image above shows observations of sea ice areal coverage from the year of 2007 to the present year. 2014's sea ice coverage is seen in red, with other years defined by the color legend on the bottom-left corner of this graphic. Taking a glance over this image, we find that this year's sea ice coverage is running in the upper percentile of coverage compared to previous years, as the red line is well above the record-setting years of 2007 and 2012. The red line is located very close to the years of 2013 (black line), 2009 (neon green line), and 2010 (yellow-ish green line). To try and see if we can pull any useful data from here for the upcoming winter, I took a look at winter temperature anomalies for years with sea ice coverage similar to this year, in this case the three aforementioned years.

The results are quite ominous.

Click to enlarge
The first year we'll examine is the winter of 2009-2010. The sea ice coverage was remarkably similar to what we've experienced thus far in 2014, and is similar to what we're expected to see later on this year. Temperature anomalies during the winter of 2009-2010 were predominantly below-normal across the country. The cold was maximized in the Central Plains and Gulf Coast, while persisting across the Midwest, Plains, Ohio Valley, and Mid-Atlantic. The Upper Midwest, New England, and West Coast regions experienced above normal temperatures this winter. Overall, this winter brought about a significant cold trend to most of the nation, something we may have to watch for if this sea ice similarity stands.

Click to enlarge
The following winter, the winter of 2010-2011, also saw a remarkable similarity in sea ice between the year of 2010 and the present year of 2014, even more so than the year of 2009. The winter of 2010-2011 was yet another cold one, with the below-normal temperatures entrenched best in the Northern Plains and Southeast. Below-normal conditions were spread across the Midwest and Central Plains, all the way into the Northeast and Mid-Atlantic. The Southwest observed predominantly above-normal temperature anomalies, as did a portion of the South Plains. Small fractions of the Upper Midwest and New England regions also saw relatively warm winters, though the overall nation was gripped by below-normal temperatures. The trend of below-normal temperatures with similar sea ice coverage is quickly becoming better defined.

Click to enlarge
Lastly, the sea ice graph tells us that this past year, the year of 2013, is matching up quite well with sea ice coverage in 2014. So, as rough as it may be to do so, we must re-analyze the winter of 2013-2014. As most of us may remember, this past winter was not a good one, and temperature anomalies reflect this. Anomalies across the country ranged from several degrees above normal, to nearly ten degrees below normal. The core of the cold was placed in the Midwest and Upper Midwest, though below-normal temperatures enveloped a wide swath of the Lower 48. Only the Southwest and Southeast regions saw above-normal temperatures.

While the sample size is rather small, it is no secret now that years with similar ice coverage as the current one saw below-normal to well-below-normal temperatures in the following winter. It'll take a few more months to determine how valid this correlation may be, but this is yet another ominous sign of many that are telling of a cold winter ahead this season.



Madeleine said...

I very much appreciate your valuable research and insight. Thank you Andrew, for all that you do.

Anonymous said...

This piece would be more convincing if data were presented that gives some indication that there is a good correlation between polar ice cover and NA winter temperatures, both warm and cold. Does data exist that show warm winters with less ice cover? If not, I don’t know if this is coincidence or correlation.