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Arctic Update

August 18, 2013
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By Paul Homewood

 

I don’t usually report on the Arctic, as others do this well. Nevertheless, we seem to be at an important turning point for this year, so let’s look at some of stats from DMI, the Danish Meteorological Institute.

 

 

Temperatures

    

image

Daily mean temperature and climate north of the 80th northern parallel, as a function of the day of year.

http://ocean.dmi.dk/arctic/meant80n.uk.php

   

Temperatures have been running below the mean, which is based on a baseline of 1958 –2002, since April. They are now dropping sharply, and are now at the level we would expect to see probably in another two or three weeks. As this is very much a model based dataset, it is worth repeating DMI’s warning not to take the actual temperatures too literally:-

 

“Therefore, do NOT use this measure as an actual physical mean temperature of the arctic. The ‘plus 80 North mean temperature’ graphs can be used for comparing one year to an other.”

 

So it does not automatically follow that the whole area is below freezing yet. But, comparisons against the mean are valid. (The same sort of warnings are given by other datasets, such as GISS – see their “Elusive Absolute Surface Air Temperature”).

 

 

 

Ice extent

image

http://ocean.dmi.dk/arctic/icecover.uk.php

 

Currently, extent is running well above that of recent years, and is within a standard deviation of the mean.

Sea ice extent minimums are normally reached around the 10th September, but,given the fall in temperature and barring external factors such as storms, we could well see the minimum reached earlier this year, maybe even as early as the end of August. The earliest minimum on record was the 2nd September 1987.

7 Comments
  1. August 18, 2013 1:37 pm

    Reblogged this on CraigM350.

  2. David permalink
    August 18, 2013 4:18 pm

    This DMI figure is around 1 million km^2 higher than the 15% extent figures from all the other 15% extent producers.

    This appears to be due to the DMI method of counting land areas as sea ice extent where these overlap with sea ice at coastal locations.

    All the other producers such as NSIDC and JAXA currently show extent well below the single standard deviation range.

    http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
    http://nsidc.org/arcticseaicenews/

    • August 18, 2013 6:23 pm

      I hope you tell DMI they are wrong then!

      (BTW – I expect a pat on the back when I get to 300000 views tomorrow!)

      • David permalink
        August 18, 2013 6:26 pm

        At least you’re honest about why you’re doing this.

        You get a pat on the back for that.

  3. Sundance permalink
    August 18, 2013 8:41 pm

    GISS is model based too isn’t it? They don’t have thermometers in the Arctic either and extrapolate the temperature based on other temperature stations as much as 1200 Km away. So to be consistent we should be careful about warming claims by GISS.

  4. John F. Hultquist permalink
    August 19, 2013 3:39 am

    300,182 hits + 1 – – – Cheers.

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