Wind Patterns May Be Responsible for Arctic Sea Ice Loss

From the NASA webs site, with a hat tip to the Reference Frame:

A new NASA-led study found a 23-percent loss in the extent of the Arctic’s thick, year-round sea ice cover during the past two winters. This drastic reduction of perennial winter sea ice is the primary cause of this summer’s fastest-ever sea ice retreat on record and subsequent smallest-ever extent of total Arctic coverage. …

Nghiem said the rapid decline in winter perennial ice the past two years was caused by unusual winds. "Unusual atmospheric conditions set up wind patterns that compressed the sea ice, loaded it into the Transpolar Drift Stream and then sped its flow out of the Arctic," he said. When that sea ice reached lower latitudes, it rapidly melted in the warmer waters.

"The winds causing this trend in ice reduction were set up by an unusual pattern of atmospheric pressure that began at the beginning of this century," Nghiem said.

The Arctic Ocean’s shift from perennial to seasonal ice is preconditioning the sea ice cover there for more efficient melting and further ice reductions each summer. The shift to seasonal ice decreases the reflectivity of Earth’s surface and allows more solar energy to be absorbed in the ice-ocean system.

Climate is complicated, so there may still be more to the phenomenon than we understand today, but certainly this is a more satisfying answer the "global warming" since Antarctic sea ice was hitting a 30 year high at the same time Arctic ice was at a 30-year low.

One of my favorite topics in climate discussion is "what is normal?"  We have observed climate really intensely for maybe 30 years, and with any kind of reliable measurements for no more than about a hundred years.  So given that climate moves in hundred thousand and million year cycles, how can we be sure our reference point, given 30 years of observation, is really "normal."  One funny aspect of this is how often the headline has been flashed over the last few weeks that Arctic ice is at an "all-time" low.  Really?  You mean the lowest it has been in the 6 billion year history of earth?  Well, no, just the lowest since 1979 when we started measuring by sattelite.  (For those without a calculator, "since 1979" is really only 0.0000005% of "all-time.")

Update:  Anthony Watt has much more

5 thoughts on “Wind Patterns May Be Responsible for Arctic Sea Ice Loss

  1. James Howe

    This is interesting information but I have a simple question. When the researcher talks about wind patterns set up at the beginning of ‘this century’, I have to assume he means starting in 2000, not 1900? If so, global warming supporters could easily argue that AGW is the driving force behind these changing winds and so ultimately it is still AGW that is causing the ice to melt, just not directly.

  2. Larry Sheldon

    OOOO! A nit to pick! “This century” started in 2001, but other wise that is a middling good question.

    The one in the area that intrigues is this: Somebody famous set out from Europe some years ago looking for the “NorthWest Passage to China” seems like. Long enough ago that it was mention in history books I read as a kid, so you know it was a _long_ time ago. And it seems like there were reports of successful transits although it never became the boon that is now predicted. How did they do that?

    And on the question about “what is ‘normal’”…I always thought (with respect to people) normal=boring and with respect to everything else “normal” was the value such that half the examples measured were above it and half were below it.

    Since there seems to be no agreement on what was measured, what the measured values are, and which of myriad adjustments are or are not, should or should not, were or were not applied the task of determining what “normal” means belongs in the “too hard box[1]“.

    [1] Bernie Peters taught me to say that.

  3. Bearster

    “…global warming supporters could easily argue that…”

    The error in this thinking is that it lets AGW (or anyone) just make up claims, and puts the onus of proof on anyone who doesn’t accept it on blind faith.

    The proper approach is to demand that the proponent prove his claims. Since AGW predicts and claims many things which are untrue, it should be rejected by anyone whose standard is reason.

    Environmentalism is a faith-based movement, i.e. a religion.

  4. James Howe

    “…OOOO! A nit to pick! “This century” started in 2001….”

    Quite correct. Carelessness on my part.

    “… The error in this thinking is that it lets AGW (or anyone) just make up claims, and puts the onus of proof on anyone who doesn’t accept it on blind faith. …”

    Also correct, but that seems to be pretty much par for the course these days.

  5. Ivan

    Roald Amundsen was successful in making the Northwest passage in the early 20th Century, but I believe he wintered over at least 1 year (looks like 2 according to Wikipedia). He spent that time studying the natives and how they survived in such an inhospitable climate. As I recall from a documentary I saw he came close to losing his ship to the ice at least once.

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