NASA Sees Arctic Ocean Circulation Do an About-Face

Source: JPL and NASA website

PASADENA, Calif. – A team of NASA and university scientists has detected an ongoing reversal in Arctic Ocean circulation triggered by atmospheric circulation changes that vary on decade-long time scales. The results suggest not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming.

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Reporting in Geophysical Research Letters, the authors attribute the reversal to a weakened Arctic Oscillation, a major atmospheric circulation pattern in the northern hemisphere. The weakening reduced the salinity of the upper ocean near the North Pole, decreasing its weight and changing its circulation.

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"While some 1990s climate trends, such as declines in Arctic sea ice extent, have continued, these results suggest at least for the 'wet' part of the Arctic -- the Arctic Ocean -- circulation reverted to conditions like those prevalent before the 1990s," he added.

The Arctic Oscillation was fairly stable until about 1970, but then varied on more or less decadal time scales, with signs of an underlying upward trend, until the late 1990s, when it again stabilized. During its strong counterclockwise phase in the 1990s, the Arctic environment changed markedly, with the upper Arctic Ocean undergoing major changes that persisted into this century. Many scientists viewed the changes as evidence of an ongoing climate shift, raising concerns about the effects of global warming on the Arctic.



Read more: http://www.jpl.nasa.gov/news/news.cfm?release=2007-131

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Faux Noise had this as their "neener neener" top news story.

glub... glub... glub....


(gasp!) ... (cough!)...



neener neener!




glub glub glub...

The shifts are strengthened by melting arctic ice, which is lowering ocean salinity.

Global warming scientists have already explained this.

And the extent of the cryosphere (aside from the "wet" part of the Arctic) is really a major thing to watch. Also, the long-term ecosystem changes, evident when Inuit elders note that they're seeing wildlife they haven't really experienced before -- these are things that are outside the scope of this study.

I study climatology and have always been fascinated by oscillations/teleconnections. Seems to me that we're looking at a similar kind of thing as for El Nino ... global warming will unfold, with the patterns from the oscillations (like the Arctic Oscillation and Southern Oscillation) overlaid on top of it. And those patterns may not stay the same in any case, due to the shifts in the energy balance.

Thanks for posting!

what their top story was. They seem to think they have something here, even though they don't understand it.

DUers need to understand what ammunition the deniers are trying to use.

they were once 1,000 and 2,000 year weather systems ---
now they are regular events

I seem to recall that some researchers tried to come up with different classifications (weak, moderate, strong, extra-strong, etc.), over the past few centuries. Might be this team?

QUINN WH, NEAL VT, DEMAYOLO SEA
EL-NINO OCCURRENCES OVER THE PAST 4-1/2 CENTURIES
JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS 92 (C13): 14449-14461 DEC 15 1987

I thought it might be interesting to separate out the different events and look at changes in frequency for each type. (After updating the last couple of decades of data, following their classification system.*)
Yes, I wouldn't be surprised if there's been a shift in how the Southern Oscillation behaves. I'm waiting to see if the Pacific Decadal Oscillation (which affects my area) changes in timing and/or strength.


*I've got a bit of a hunch -- like the time I wondered if it would be worth checking the minimum (usually nighttime) average daily temperatures. It turned out that I should have kept working on that, because other people started finding that the warming signal showed up at night, even before the daytime maximum values. I've got to learn to make time to follow things up ...

and the article posted her is one intended to confuse and distort ---

However, YES, I think the overnight temperatures have been a big worry for a long time now ---
the earth doesn't cool as it once did -- and I'm sure that creates repercussions somewhere along the line.

More basically, I think we have done such great harm to nature -- of which we are a part --
that we are going to have more immediate threats to food/water ---

For almost a decade now, the govt has been experimenting with "weather modification" ---
i.e., chemtrails --

Last Sunday I was at the shore --- beautiful clear blue sky til about 3pm and then the
chemtrail clouds start drifting in and making the sky milky ---

Weren't directly overhead this time --- usually are.

With gas prices as they are --- I can't see why we aren't moving to buy more local produce ---
Asparagus from Peru?

I'm going to check out the work of the people mentioned in the article, directly. A lot of scientists I know have said that it's rather rare when the media report the main points of their papers accurately (rather than seizing on part and ignoring the main finding altogether, or worse, getting things totally the wrong way around). As you say, there's a lot of distortion going on.

can sell their ocean front property to GW deniers for a good price.

Try National Geographic ---
or "Song for a Blue Planet" -- at your library

Years ago, while everybody was saying global warming was a HOAX, the man-made global warming crowd predicted the melting of the ice caps. Now that its finally happening, the Right wants to come up with any narrative to explain why its really happening other than human causes. But IT WAS PREDICTED. I won't take any alternative global warming theory seriously until it PREDICTS something that's going to happen like the man-made global warming crowd did...that's the power of science, it predicts what's going to happen.

suppress a smile with this tidbit, but it doesn't mean the ice isn't melting, or that GW isn't real. As Lisa said in an earlier reply, the changes in oscillations are overlaid on the GW problem.

NASA's director is a bushco bot. NASA's latest finds go against hundreds of peer reviewed papers. Should we trust NASA?

THIS has been anticipated --- and a recognized coming and very serious problem ---

THIS is simply more Global Warming ---



QUOTE ---
ongoing reversal in Arctic Ocean circulation triggered by atmospheric circulation changes that vary on decade-long time scales. The results suggest not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming.

snip

Reporting in Geophysical Research Letters, the authors attribute the reversal to a weakened Arctic Oscillation, a major atmospheric circulation pattern in the northern hemisphere. The weakening reduced the salinity of the upper ocean near the North Pole, decreasing its weight and changing its circulation.
UNQUOTE

This denial by the GOP is now bordering on criminality...