Weatherdem's Weblog

Bridging climate science, citizens, and policy

State of the Poles – Feb. 2011


The state of global polar sea ice area one month into 2011 is troublesome: well below climatological conditions continue to persist (1979-2009).  Sea ice in the Arctic continues to track significantly below average.  Meanwhile, Antarctic sea ice has switched from well above average extent in mid-December to challenging record lows for the last days of January.  As a result, global sea ice area continued to rapidly decrease during January.  The trend for January is normal, but the values of extent are abnormal.

In last month’s post, I rhetorically asked whether the yearly absolute minimum global sea ice area would look more like 2005, 2009 and 2010 (~15 million sq. km.) or whether 2011′s minimum would be more like 2006 and 2007 (~14.5 million sq. km.).  Click-thru to the link provided above and you’ll see that 2011 unfortunately already looks more like 2006 and 2007.  With about one month remaining in the Southern Hemisphere’s melt season remaining, and with the freeze season in the Northern Hemisphere winding down, this year’s global minimum may not have been reached yet.  In 2006, 2007 and 2009, extent hovered near 14.5 million sq. km. for about one month.  Regardless of the specific date and the specific absolute minimum extent value, the trend in January’s from 2008 through 2011 look very similar to the trend from 2003 through 2007.  Global sea ice is once again in bad condition at the end of January, 2011.

Arctic Ice

According to the National Snow and Ice Data Center, Arctic sea ice extent set a record low in January.  Averaged over January 2010, Arctic sea ice extent was only 13.55 million sq. km., which was 50,000 sq. km. below the previous record low set in 2006.  Areas like Hudson Bay and the Davis Strait finally froze over in January, nearly 2 months behind normal.  The Labrador Sea remains unfrozen, even at this extremely late date in the Northern Hemispheric winter season.

In January, the ice extent was about 1.1 million sq. km. less every day than the normal value.  This was the first time on record that the extent was so low for so long during the first calendar month of the year.  The extent was >500,000 sq. km. lower than during the same period in 2008-2010. Moreover, the last 2 times a calendar year started out anywhere near this negative was in 2006 and 2007.  In 2007, the all-time record low ice extent was set.  For the record, the extent at the end of January 2011 is ~100,000 sq. km. lower than it was in either 2006 or 2007.  Does that mean that a new record low extent will be set this year?  Not necessarily.  2007 witnessed weather conditions that helped ice flow out of the upper Arctic and into warmer waters, where it melted.  That hadn’t happened prior to 2007 in the satellite era, nor has it happened since.  However, the record low volume of ice that was measured in 2010 could mean that ice area extent is in danger of shrinking to near-record lows again in 2011.

The change in January ice extent has been measured at -3.3% per decade by the NSIDC.  What that means is as of the end of January 2011, the Arctic has only 13.55 million sq. km. of sea ice extent, while as of the end of January1978, the Arctic had 15.5 million sq. km. of sea ice.  That is an enormous and significant difference.

Arctic Pictures and Graphs

Here is a satellite representation of Arctic sea ice conditions from February 7th centered on the North Pole:

Compare these with January 6th’s satellite representation, centered on the North Pole:

The area highlighted by the white oval in the January picture has finally frozen over – only 2 months later than at any point in recorded history.  The NSIDC has a nice multi-year time-series showing how abnormal this winter’s freezing delay has been.  In the past month, the Sea of Okhotsk (east of Russia, north of Japan) has stated to freeze over.  I feel like a broken record with this, but it is doing so at a much slower pace than is normal.  The Baffin and Newfoundland sea ice also remain well behind normal schedule to freeze.

There are different factors affecting each of these areas.  As I’ve discussed previously, the Arctic Oscillation was in an extremely negative phase for months again this winter.  This allowed cold air that normally remains trapped over the Arctic to pour south and affect eastern North America and Europe.  At the same time, a huge dome of high pressure settled over northeastern Canada, allowing much warmer than normal temperatures to remain in place.  I’m not talking just a little warmer than usual, I’m talking about parts of Canada being an average of 38°F warmer for an entire month – and that month should have been one of the coldest of the year for that region.

It was recently announced that there is a phenomenon underlying all of the various weather patterns and climatic oscillations.  According to a new study, water entering the Arctic Ocean between northeastern Greenland and Svalbard is now warmer than it has been at any time over the past 2,000 years.  To make matters worse, the volume of water entering the Arctic is also greater than it was in the past.  So more water that is warmer is being funneled into the Arctic Ocean, which is resulting in a warmer Arctic from below.  This finding has serious implications for the future state of Arctic sea ice.  Even if abnormal weather patterns and oscillations didn’t set up, ice will have a harder and harder time forming and being maintained from year to year because of the additional heat being forced into the ocean.  That heat will have to dissipate prior to any ice formation, let alone ice thickening.  Like I’ve written before, the Arctic has entered into a new climate regime.  It might take a little longer for the effects of that to cascade through the climate system to places where people live.  But once it does, it will be too late to prevent the worst of further effects from continuing to cascade.

Here is the time series graph of Arctic sea ice extent with the +/- 2 standard deviations as a light-gray envelope around the climatological average through February 6th:

You can see how truly poor the Arctic sea ice conditions are with this graph.  The 2010-2011 line shows us that conditions are the worst for the date on record since the middle of December, beating out 2006-2007 every day.  Arctic sea ice continues to track far, far below climatological norms.  The up-shot from the previous paragraph is this: the conditions we’re seeing for the first time this winter are likely to be the new normal.  That thick gray line and the light-gray envelope will be shifted downward.

Antarctic Pictures and Graphs

Here is a satellite representation of Antarctic sea ice conditions from February 7th:

For comparison purposes, here is the similar picture from January 6th:

The sea ice off western Antarctica has fully melted.  The fields adjacent to the coast west and east of the Antarctic peninsula remain in good shape, largely thanks to cooler than normal surface temperatures and sea surface temperatures.  This is an example of a weather phenomenon helping to keep sea ice intact rather than destroying it.

Here is the time series graph of Antarctic sea ice extent with the +/- 2 standard deviations in light gray and the climatological mean in dark gray through the 6th:

It’s pretty obvious to see what happened during January: sea ice extent was whittled down at a much faster rate than normal.  It started out slightly above average and ended the month near the bottom of the 2 standard deviation envelope.  While conditions aren’t as dire as they are in the Arctic, Antarctic sea ice melted very quickly this year, especially considering the extent was well above the 2 standard deviation envelope back in mid-November.  It is at this point in the year that ice shelves typically start to break off.  Will 2011 have another big ice shelf break-up news story?  Stay tuned.


Here are my State of the Poles posts from January and December.

You can find the NSIDC’s February report here. The page is dynamic, so if you’re reading this after February 2011, that month’s report will show up first. If that’s the case, you can look for any report in their archive on the top pull-down tab on the right-hand side of the page.


2 thoughts on “State of the Poles – Feb. 2011

  1. Pingback: State of the Poles – Mar. 2011: Record Low Arctic « Weatherdem’s Weblog

  2. Pingback: State of the Poles – Apr. 2011: Arctic Sea Ice Steady; Antarctic Below Average « Weatherdem’s Weblog

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