Digital Diatribes

A presentation of data on climate and other stuff

November 2008 Update on Arctic Temperature – RSS

Posted by The Diatribe Guy on December 1, 2008

Arctic Region:

October Anomaly

  • Anomaly value = 0.452, in degrees Celsius
  • Of 358 total anomalies in the data, it ranks 120th
  • Of 30 October anomalies, it ranks 10th.
  • October’s anomaly is 0.45 degrees cooler than October 2007 and 0.155 degrees cooler than September 2008

Averages and trends

  • 12-month average anomaly is 0.514, which – other than the 51.3 average at the end of August 2008 – is the lowest average since the period ending January 2005.
  • The slope since inception (January 1979) is 0.27989 degrees Celsius per month, which corresponds to a warming rate per Century of 3.36 degrees. The most horrific global warming figures are extrapolated from the observed warming in the Arctic over the last few decades. And it surely has warmed fairly significantly. However, this is a regional phenomenon. The Antarctic has actually cooled slightly in the last 30 years and nobody seems to really care all that much about that. It is very obvious from the RSS data differentiation by latitude that global temperature changes are a little more complicated than the simplistic “global” notion we so often hear about.
  • We can fit a negative trend line going as far back as March 2002. So, while the anomalies are still warm, they have stopped increasing in the last 6 and a half years.
  • There is no significant recent streaks of consecutive cooling or warming stretches over previous year.
  • Last 60-month slope = -0.0053. While negative, and while recent anomalies haven’t been real high, the trend line has increased because there is a dropping off of some very high anomalies on the front end of the trend line. Given the short line and the widely fluctuating anomalies in this region, the 60-month trend whips around quite a bit. In two months, I expect it to actually swing positive, but then it should flip back to a negative trend line.
  • Last 120-month slope = 0.4589. This is a significant 10-year trend line. Since the last 5-years show a negative trend line, this still provides insight into the fact that the recent anomalies have still hovered higher than they were a decade ago. This helps explain the continued decline of ice mass through summer of 2007. Even though the Arctic was starting to cool down from its peak, it was still warm enough to continue increasing the melt. But we can now see, based on the 12-month average being the lowest in a while, that the overall anomalies have come down over the last 3 years, and we saw a higher ice mass at minimim in 2008 than 2007, and we saw a more rapid recovery into the winter. I have included a snapshot of the ice extent as of the end of November, from the IJIS site, below. You may view a current snapshot by clicking the IJIS link under “Resources” on the right of this page.
  • Arctic Ice Extent since 2002. The 2008 value is as of November 30, 2008.

  • Last 180-month slope = 0.4222, the lowest such slope since the period ending February 2003.
  • Last 240-month slope = 0.4725, – the value of this trend line has been relatively stable since December 2005.
  • Last 300-month slope = 0.3895, – the value of this trend line has been relatively stable since December 2006.

Overall trend since 1979 for the Arctic shows significant warming. This level of warming has been unique to the Arctic, and has finally subsided, at least for now, over the last 6 years.

We can now extend a trend line back to March 2002 that shows there has been no warming since that time. Actual anomalies are still quite positive, but have come down from the very high averages of a few years ago.

3 Responses to “November 2008 Update on Arctic Temperature – RSS”

  1. Jeff Id said


    I’ve been looking for the 30 year extent record. I found it once before but am having a horrible time locating it again. Do you have any reference to the full 30 year file?

  2. The Diatribe Guy said

    Jeff, I’m not sure what you saw before, but perhaps it was one of these?

  3. Jeff Id said

    Thanks Joe,

    The third link had what I was looking for. You wouldn’t believe how much time I spent on it.

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