Tuesday, February 1, 2011

Brrr!!!

As much of the country prepares for one of the worst winter storms in decades, one is led to wonder once again just what the heck is going on in the world of weather.

For example, I read a story in The New York Times recently that stated that while parts of the southern United States have had record snowfalls and cold this winter, 2,000 miles to the north in northeastern Canada and Greenland, it has been freakishly warm, both this winter and last. Their temperatures in December ran as much as 15 to 20 degrees Fahrenheit above normal. This has had an economic impact because bays and lakes have been slow to freeze and so ice fishing, hunting and trade routes have been disrupted.

What's going on here? Is this a result of global warming? Scientists warn that it is almost impossible to link a particular weather event to the larger issue of global warming, but it is very difficult for the layperson to believe that it is not somehow related. Theories about the effects of global warming have postulated that it could generate extreme weather events right around the world, and we certainly have seen some extreme events in the last twelve months, from the floods that devastated Pakistan and, now, Australia, to the Arctic chill that has descended on Europe and North America over the last two winters.

The immediate cause of our extremely cold weather seems to be that a pattern of atmospheric circulation that has in the past tended to keep frigid air locked in the Arctic has weakened considerably during the last two winters. The gate has been left open on the Arctic "fence" that kept the cold air in and that has allowed cold air to push far into the south, while at the same time warmer air has been sucked into the north. And the reason for this change MAY be that the ice on the Arctic Ocean's surface declined in September by more than 30 percent. Ice reflects sunlight, so when there is less of it the ocean absorbs more heat. That heat affects the atmospheric pressure and the circulation of air.

It's complicated and I certainly don't pretend to understand the half of it, but as we enter February with temperatures here in Southeast Texas expected to descend possibly all the way into the teens this week, we could wish that someone would find a way to shut and lock that Arctic "gate" once again.

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