The state of the Arctic sea ice in late December 2009 remains the 2nd worst of any recorded December. The areal extent of sea ice continues to be well below the climatological average, and as it has for most of 2009, significantly below the negative 2nd standard deviation of the 1979-2000 area. The areal extent of Arctic sea ice continues to be anomalously low, as it has for well over a year now. The Hudson Bay has finally iced over. The late freeze this year was due to anomalously warm waters in the Bay in 2009. The Barents Sea remains relatively ice-free for this time of year. Remember, the Arctic Ocean hasn’t seen sun in a couple of months now.
The state of the Antarctic sea ice in late December 2009 is less disturbing. After reaching a high value of ~19 million sq. km. back in late September, the 2009 melt season exceeded that of the 2008 season. That trend shifted slightly as December drew to a close – the areal extent has increased from the 1979-2000 average to the positive 2nd standard deviation. The exact value of areal extent in 2009 remains below the value measured in 2008 by a small amount. The trend found in December is likely due to this year’s storms: both tracks and intensities vary year to year.
Globally, the extent of sea ice in 2009 continued the trend seen throughout the Aught’s: anomalously low extent, as seen in this graph. There were only a handful of times when global ice extent was significantly above the climatological average these past 10 years and none had the magnitude of the record low extents seen in 2007 and 2008. When viewed in the long term, it is clear to see that the state of the poles has shifted in the past 10 years. The majority of that state change has been in the Arctic.
For comparison purposes, here is the similar picture from August:
Here is the time series graph of Arctic sea ice extent with the +/- 2 standard deviations through yesterday:
You can find the NSIDC’s December report here. The page is dynamic, so if you’re reading this after early January, the January report will show up first. You can look for the December report on the top pull-down tab on the right-hand side of the page. Of note: November had the 3rd lowest average extent for the month since 1978. Ice is declining at a 4.5% rate per decade. The NSIDC report also shows the anomalously warm pools of air near Hudson Bay and the Barents Sea in November.
Here is a satellite representation of Antarctic sea ice conditions from yesterday:
Here is the time series graph of Antarctic sea ice extent with the +/- 2 standard deviations through yesterday:
Nothing else jumps out at me at the moment. We’re in the middle of the growth and melt seasons for the Arctic and Antarctic, respectively. The maximum/minimum extents will be reached sometime in March. On a related note, the year is drawing to a close, which means that 2009′s CO2 concentrations and global temperature data will soon be made available. When they’re released, I will write on them. As we head in to 2010, keep in mind that many centers around the world are predicting record global temperatures to be set. I will keep a close eye on this in the future.
Cross-posted at SquareState.