Tuesday, January 28, 2014

The Polar Vortex Collapse - A Longer Perspective

While the purpose of this blog is to comment on Arctic methane, this topic intrigued me, and may have a relationship to Arctic methane concentrations, but that will be discussed later.

There has been a lot of media coverage of the "polar vortex" and its collapse in the past few weeks. This has been viewed as an urgent event, yet in most every case - seen as one without comparison.

So I thought I'd look back at three to six years of comparative surface temperature anomalies to visualize the similarities or differences with the last few years.

One popular view of the surface temp anomaly has been the ESRL/PSD/NCEP Operational Climate Graphic (see: http://www.esrl.noaa.gov/psd/map/images/fnl/sfctmpmer_01a.fnl.html ). The graphic is updated daily, but I have not found an ftp storage site, so have saved these almost daily for the last couple of years. So here is the comparison of 2012-2014.

The NCEP operational surface temperature anomaly for Jan 27, 2012 was:

One can note that there was significant heating in the Arctic, with the difference being that the polar anomalies including warmer than average temps over North America and Siberia.

The NCEP operational surface temperature anomaly for Jan 27, 2013 was:
 The high temperature anomaly was still present, with the coldest temp anomaly located over Alaska, but the vortex still seems disrupted, with warming over much of North America.

The NCEP operational surface temperature anomaly for Jan 27, 2014 is:

Here we see how dramatically different this year is compared to 2012 and 2013. While this does not make a trend, it does demonstrate the higher anomalous temperature change, based upon these scales and anomaly base of 1985-1996.

For further comparison, I decided to change perspectives, and look at the longer trend using the daily composites surface temperature anomaly (1981-2010) for 2008-2014, but for January 25, since the 27th's data is not yet available. See http://www.esrl.noaa.gov/psd/data/composites/day/

The graphics for January 25, 2008 reveal anomalous cold in the Arctic and over North America, with heating over central Siberia.

The graphics for January 25, 2009 reveal anomalous warm/cold split. with the Arctic having anomalously warm temperatures compared to North America - seemingly supporting a "Warm Arctic - Cold Continents" model for one half of the globe.
The graphics for January 25, 2010 reveal anomalous warmth in the Arctic and over North America, supporting the WACC concept, but Europe and Siberia were unusually cold.
The graphics for January 25, 2011 reveal a fractured mix of warmth and cold anomalies over the Arctic and the continents.
The graphics for January 25, 2012 reveal an anomalously cold Arctic basin, and warmer surface temperatures over eastern Siberia, and the Kara, Laptev, Barents and Norwegian seas and even higher over North America. However, this is not as dramatic as 2014, since the scale is +/- 15 K/C.
The graphics for January 25, 2013 reveal another fractured mix of warm and cold anomalies over the Arctic and continents.
The graphics for January 25, 2014 reveal the highest concentration of anomalous warmth since 2010, which depicts the warming on the same +/- 20 K/C scale. The stronger anomalies are apparent, and the colder anomalies are moved out of the Arctic.
It will be interesting to see how long this pattern will last.

A4R