Extraordinary warmth in the Arctic

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  • Extraordinary warmth in the Arctic
    11.01.2011 10:57

     

    As the UK heads into a spell of much milder, rainy and occasionally windy weather through the rest of this week, it is worth reminding ourselves that although the days are growing longer we are still not even half way through the meteorological winter.

    Any talk of spring coming early is vastly premature, and indeed there are indications of a return to colder conditions next week as winds turn to come at us from the north or east again for a while.

    Because the UK was so abnormally cold through December and into early January and because the atmosphere strives for balance, it stands that some other part of the northern hemisphere should have been unusually warm.

    And so it proves when we take a look at Greenland and northeast Canada, where it has regularly been warmer than our own frigid shores.

    In fact there has been record-breaking warmth. South Baffin had temperatures 20 degrees above normal in the first week of January, with, for example, Iqaluit breaking its date record on January 3rd. A maximum of +1.2 deg C might not sound impressive but this is well inside the Arctic Circle, and the previous record for the day was -1.7 deg C in 1970.

    Pangnirtung was even more impressive, rising to +8 deg C on January 4th, about the same as London today, trouncing the previous date record of -3.7C in 2002.

    And on December 22nd the world’s most northerly permanent settlement at Alert, at the northern end of Ellesemere Island and only 817 kilometres from the North Pole, rose to +0.2 deg C, which was thirty degrees above the December average.

    So clearly the globe as a whole has not suddenly dramatically cooled, even if many of the large populations centres across Europe and the USA had a very cold and snowy start to the winter.

    It is hard to say why such a hugely complex entity as the Earth’s atmosphere has produced this change. Among other things there is speculation that a shift in the currents of the North Atlantic might have a rôle.

    The Labrador Current, a cold flow out of the Arctic Ocean, along the Labrador coast and around Newfoundland, seems to have weakened in recent years, according to the Swiss Federal Institute of Aquatic Sciences and Technology (EAWAG).

    Under normal circumstances it interacts with the warm north-eastward flow of the Gulf Stream, deflecting it away from the coast of eastern Canada. However, at the moment it seems as though those warm waters are moving farther north into the northwest Atlantic.

    It is speculated that complex ocean-atmosphere interactions might have an effect on the flow of winds around the northern hemisphere and contribute to the blocked pattern that has produced these extremes of temperature.

    Nothing is certain in that regard. What is certain, however, is that the warmth has forced Environment Canada still to produce marine forecasts for the HudsonStrait, where normally there would be no need once ice had grown through November and December.

    By: Stephen Davenport