The climate is changing: the Arctic Dipole emerges
The dramatic loss of Arctic sea ice in recent years has created a fundamental new change in the atmospheric circulation in the Northern Hemisphere that has sped up sea ice loss and is affecting fall and winter weather across most of the Northern Hemisphere, according to several recent studies. Arctic sea ice loss peaks in September and October, exposing a large area of open water that heats the air above it. This extra heat has helped drive September - November air temperatures in the Arctic to 1°C (1.8°F) or more above average over about half of the depth of the lower atmosphere (Figure 1). This deep layer of warm air has grown less dense and expanded, pushing the top of the troposphere (the lower atmosphere) higher. The result has been a decrease in the pressure gradient (the difference in pressure) between the North Pole and mid-latitudes. With not as much difference in pressure to try and equalize, the jet stream has slowed down in the Arctic, creating a major change in the atmospheric circulation for the Northern Hemisphere.
Figure 1. Cross section of Arctic temperature anomaly from 1000 mb (the surface) to 300 mb (roughly, the height of the top of the lower atmosphere or troposphere). Cross section is taken along the Date Line (180°W), from 60°N latitude (left side) to the North Pole (right side), for September - November for the 12-year period 1998 - 2009. Three year averages were done to reduce the amount of year-to-year noise associated with natural variation. Other cross sections along different lines of longitude show similar results, though typically with more warming aloft and less warming at the surface. Image credit: NOAA/ESRL.
A new atmospheric pattern emerges: the Arctic Dipole
In a 2008 article titled, Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system Zhang et al. show that the extreme loss of Arctic sea ice since 2001 has been accompanied by a radical shift of the Arctic atmospheric circulation patterns, into a new mode they call the Arctic Rapid change Pattern. The new atmospheric circulation pattern has also been recognized by other researchers, who refer to it as the Arctic Dipole (Richter-Menge et al., 2009). The old atmospheric patterns that controlled Arctic weather--the North Atlantic Oscillation (NAO) and Arctic Oscillation (AO), which featured air flow that tended to circle the pole, now alternate with the new Arctic Dipole pattern. The Arctic Dipole pattern features anomalous high pressure on the North American side of the Arctic, and low pressure on the Eurasian side. This results in winds blowing more from south to north, increasing transport of heat into the central Arctic Ocean. The Arctic Dipole pattern occurred in all summer months of 2007 and helped support the record 2007 summer reduction in sea ice extent (Overland et al., 2008). Overland et al., 2010 also found that the Arctic Dipole pattern tended to create an increase in easterly winds in the lower half of the atmosphere of 40% in fall, between 2002 - 2008. Fall 2008 through spring 2009 featured the old AO pattern. The new Arctic Dipole pattern re-appeared in June - July 2009, but the old AO pattern dominated in August - September, resulting in greater sea ice extent than in 2007 and 2008. The Arctic Dipole pattern was active again in October, inactive in November, and reasserted itself this December. As a result, Arctic sea ice reached a new record minimum for a 10-day period in early November, increased above record lows during late November and early December, and appears poised again to reach a new record minimum later this December (Figure 2).
Figure 2. Sea ice extent in the Arctic for this year (blue line) compared to the record low year of 2007 (green line) and 1979 - 2000 average (gray line). One could make the ice loss looks less significant by using the full satellite data record from 1979 - 2008 for the average. Image credit: National Snow and Ice Data Center.
Arctic Dipole blamed for colder winters in East Asia
It turns out that the new Arctic circulation patterns help to intensify the Siberian High, a large semi-permanent region of surface high pressure prevalent in winter over Siberia. According to Honda et al. (2009), this results in increased flow of cold air out of the Arctic in early winter over eastern Russia, Japan, Korea, and eastern China, causing colder temperatures. By late winter, the pattern shifts, resulting in colder than average temperatures from East Asia to Europe.
Arctic Dipole blamed for drier winters in Northern Europe
Francis et al. (2009) found that during 1979 - 2006, years that had unusually low summertime Arctic sea had a 10 - 20% reduction in the temperature difference between the Equator and North Pole. This resulted in a weaker jet stream with slower winds that lasted a full six months, through fall and winter. The weaker jet caused a weaker Aleutian Low and Icelandic Low during the winter, resulting in a more negative North Atlantic Oscillation--a pattern that usually brings reduced winter precipitation over Alaska and Northern Europe and increased precipitation over Southern Europe. A more negative NAO also tends to bring cold winters to eastern North America and Europe. Though it was not mentioned in the article, reduced Arctic sea ice may also cause dry early winter conditions in the U.S. and the Caribbean (Figure 3). The authors noted that strong La Niña or El Niño events can have a much larger influence on the wintertime atmospheric circulation, which will overshadow the changes due to Arctic sea ice loss.
Figure 3. Difference in early winter precipitation (November - January) between five years that had low Arctic sea ice (2005, 2006, 2007, 2008, and 2009), and five years that had unusually high Arctic sea ice extent (1981, 1984, 1986, 1989, 1993). Note that low sea ice may be responsible for dry conditions in early winter for the Caribbean and most of the U.S.
Commentary
Arctic sea ice loss appears to have created a new atmospheric circulation pattern that brings more warm air in the Arctic, creating a positive feedback loop that causes even more sea ice loss. This feedback loop increases the likelihood that an ice-free Arctic in the summer will indeed come by 2030, as many Arctic experts are predicting. It's worth noting that such an atmospheric circulation shift was not predicted by the climate models. Indeed, the loss of Arctic sea ice over the past three years exceeds what any of our models were predicting (Figure 4). While we can rightly criticize these models for their inaccuracy, we should realize that they are just as capable of making errors not in our favor as they are of making errors in our favor.
Figure 4. Arctic sea ice extent from observations (thick orange line) and 13 model forecasts used to formulate the 2007 IPCC report (light lines). The thick black line is the multi-model ensemble mean, with the standard deviation plotted as a dashed black line. Image has been updated to include the observed 2008 and 2009 measurements. None of the models predicted the record 2007 sea ice loss. Image credit: Arctic sea ice decline: Faster than forecast by Stroeve et al., 2007.
References
Francis, J.A., W. Chan, D.J. Leathers, J.R. Miller, and D.E. Veron, 2009, "Winter Northern Hemisphere weather patterns remember summer Arctic sea-ice extent", Geophysical Research Letters, 36, L07503, doi:10.1029/2009GL037274.
Honda, M., J. Inoue, and S. Yamane, 2009. Influence of low Arctic sea - ice minima on anomalously cold Eurasian winters, Geophys. Res. Lett., 36, L08707, doi:10.1029/2008GL037079.
Overland, J. E., M. Wang, and S. Salo, 2008: The recent Arctic warm period, Tellus, 60A, 589.597.
Overland, J. E., and M. Wang, 2010: Large-scale atmospheric circulation changes associated with the recent loss of Arctic sea ice. Tellus, 62A, 1–9.
Richter-Menge, J., and J.E. Overland, Eds., 2009: Arctic Report Card 2009, http://www.arctic.noaa.gov/reportcard.
Simmonds, I., and K. Keay (2009), Extraordinary September Arctic sea ice reductions and their relationships with storm behavior over 1979.2008, Geophys. Res. Lett., 36, L19715, doi:10.1029/2009GL039810.
Wu, B., J. Wang, and J. E. Walsh, 2006: Dipole anomaly in the winter Arctic atmosphere and its association with sea ice motion. J. Climate, 19, 210-225.
Zhang, X., A. Sorteberg, J. Zhang, R. Gerdes, and J. C. Comiso (2008), Recent radical shifts of atmospheric circulations and rapid changes in Arctic climate system, Geophys. Res. Lett., 35, L22701, doi:10.1029/2008GL035607.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 — Blog Index
the ditches are full but nothing on the roads yet,hope it stays that way.cold rain today but 70s sunday and monday then more rain from calif.tuesday.enough of the el nino for 2009.we need a drying out period
the crawdads love it so should be a bumper crop soon
Bottom map is 12-25-09, top is 12-26-09.
Can I come eat with you???LOL...I love some mud bugs!!!
Yes flooding here too in Mobile...
I think we are going to break the 5' mark for this year..... Then become the wettest city in the country again......
What else is new for us here
Taco :0)
One point where you are wrong and is labelling me as a "believer" who is following this as one would some sort of religion. I would quickly change my view if you could produce credible data that supports a different conclusion. Even the most credible bloggers here have no means of proving that humans aren't causing in part the global warming that has been observed. The overwhelming scientific and circumstantial evidence points to the AGW theory as one reason for our warming climate. Furthermore, I feel that our use of fossil fuels is unnecessary and wasteful and I would like to see powerful legislation that quickly changes the way we produce energy. I agree cap and trade is probably one of the weakest ways to produce this change. I do think its better than nothing and when it fails the lesson will be used to accomplish even better goals in mandating the use of sustainable energy.
I could count the number of times that you used the termyou in your post. I think most of the lurkers will agree that your assertions are unfounded. Except those to whom you a preaching as your choir.
You yourself act as if the science is settled in you favor and that AGW is a sham, that is a bit hypocritical don't you think?
P.S. I will only ignore someone if they threaten me or my family on this blog. Such threats haven't occured, and so I have not ignored anyone. I force myself to read and respond to your posts and see your point of view as you are one of the most outspoken members against the AGW "religion". It helps me learn new ways to talk to people who want to disagree with research backed information that I am charged with teaching.
Good afternoon -- I do so like it when folks still have a sense of humor and see a silver lining in otherwise nasty circumstances -- crawdad stew, crawdad gumbo, Maryland crawdads (j/k -- cooked with "Old Bay Seasoning").
Have any of our Mississippi posters seen the new Mississippi Cottages? The more permanent housing for those who've survived floods? I'm dying to see them up close and personal, and I truly hope they are as nice as I've read about. The pictures are so darn "cute", but are they as great as cracked up to be?
Images of Mississippi Cottages
Heck I think everybody left.....
No one chatting right now....
Be verry verry quite
I guess everyone went Christmas shopping!
Oh well, maybe I should take the hint. Sun is shining here. The neighbors just got a huge load of dirt; I think they may be putting in a big garden -- hope so, doesn't seem to be a plumbing problem. Guess they liked the fresh, organic tomatoes from our pitiful little garden (we get too much shade from their tree, lol).
Barry, there is nothing wrong with putting people on ignore. I admit this is the first year I have done so on the blog. There are a number of people on here with whom I disagree on many levels and we have a wonderful relationship and exchange ideas. I had often put my children on "ignore" when they misbehaved.
The only people I put on ignore are those who constantly use the following words or phrases:
cap and trade
elitist
aristocracy
use the word anthropogenic more than once (especially if they spell it correctly because more than likely it was copied from some text.)
raw data
peer review
smoking gun (stolen from the Watergate era)
alarmists
that Greenland must have been green once or they wouldn't have named it that. (Maybe 80 million years ago.)
That the earth is just in a normal cycle (Remember the beginning of Superman when the Council said Krypton was just shifting its orbit?)
That Swedes are smarter than Norwegians.
"Poof"
Yes I'm about to leave soon and go and do some shopping my self.... I want leave with out a umbrella cause it is cold and raining "Ugh"
Jawohl!
HA! Nope, just that ESP thingee again. Note our last two posts were at the exact same time!
Nice to see you, Herr Professeur...mixing my pitiful knowledge of languages!
Hi, Barry! With my filter set on "Below Average" I never see aforesaid person(s), except when s/he's quoted :)
Could not see their post. Must be one of the ones I have on ignore. I believe it may have been the one who called me an "elitist". Not sure though. One shouldn't make accusations until it can be proven. Perhaps I should present it for a peer review before the aristocracy. Wouldn' want to be labeled a misanthrope. Actually, I enjoyed being called an elitist; gives one a certain stature which elevates him above the rest. Ah, that lofty feeling.
All is quiet around the US right now, compared to earlier in the week, except for flooding rains along the Gulf Coast, the Lake Effect Snow events appear to be winding down, after dropping 2-3' of snow on the Tug Hill Plateau , near Watertown, NY and south of Buffalo, NY and the on-going snow/rain event in CA.
The tropics In India, Australia are pretty active and the remnants of Cleo are hanging around.
And those in the CONUS, who live in the S Plains or along the Gulf Coast, have visions of a "White Christmas" running through our heads, compliments of the GFS runs, but that is about 300 hrs out!!
And, yeah, the "climate debate" is also simmering on a low heat!!
Nope, I always enjoy your well-crafted responses.
I HAD to put the poster called JFlorida on ignore because he would not heed my pitiful pleas to stop quoting! Say, has he been banned or something, because the blog flowed nicely yesterday without all the uh, dissertations (I'm trying use a "nice" word)!
When was roll call?
Chuckle, do I need to say "my bad"?
Point of clarification, is that how one can see who(m) is or isn't banned, by checking the directory?
Hey Pat, thanks for those kind words, but barry is a blog buddy of mine. We were just goofing on some other bloggers. It wasn't directed at me. But at least I now you have my back. We learned the hard way, didn't we???
Thanks again.
In 1969, neither Gore nor his father was a supporter of the Vietnam War. However, as a college graduate, he could no longer defer being drafted into the U.S. military. In addition, his "low draft number assured that he would be called up soon."[26] In debating how to proceed, his father, Albert Gore, Sr., later recalled that Gore "sat around with his mother and I in the living room and talked about it. He said he didn't believe in the Vietnam War. I said, 'Well, it isn't given in our law for an individual to go contrary to the law.' We discussed all the various things young men were doing to dodge the draft."[26] Also according to his Senate biography, Gore's "mother said that she would support whatever he wanted to do – 'including going to Canada with him.' "[26] The Washington Post later noted in 1999 that very few of his Harvard classmates went to Vietnam. Instead, "most of his peers at Harvard were looking for a way out, and finding one. Some took refuge in the National Guard or the reserves, options that might save them from Vietnam. A few resisted, became conscientious objectors or left for Canada."[25]
Gore has stated that he finally enlisted in the army for two reasons: he was concerned over the impact it would have upon his father's career and he did not want someone with fewer advantages than he to go in his place. Al Gore, Sr. was engaged in a difficult political campaign for the 1970 Senate election, which would likely have been adversely affected if his son did not enlist in the military.[27] Al Gore, Sr., had authorized American involvement in Vietnam by voting for the Gulf of Tonkin Resolution in 1964, but by 1969 had become a vocal opponent of the war.[28] Thus according to the New York Times, the elder Gore appeared to some to be "too tolerant of social protest of all kinds and of change in general. Young Al worried that if he found a way around military service, he would be handing an issue to his father's opponents."[28]
Gore with the 20th Engineer Brigade in Bien Hoa as a journalist with the paper, The Castle Courier.
Gore also chose to enlist because he did not want someone to go in his place. Actor Tommy Lee Jones (a former housemate) later recalled Gore saying that "if he found a fancy way of not going, someone else would have to go in his place."[19][29] His Harvard advisor, Richard Neustadt, also stated that Gore, "decided that he would have to go and that he would have to go as an enlisted man because, he said, 'In Tennessee, that's what most people have to do.'"[27] In addition, Michael Roche, his editor for The Castle Courier, stated that "anybody who knew Al Gore in Vietnam knows he could have sat on his butt and he didn't.
Taco :0)
See you later, dear. I think you'll find my Christmas wish list at Neiman Marcus!
(j/k...I WISH...more like Target!)
Until someone can explain the growth in Antarctica I will be skeptical of global warming.
The whole world needs to adopt China's one-child policy
Whoops!
What I Meant Was You People Should Only Have One Child
Typical "Do as I Say Not as I DO" SOP for AGW (err climate change) folks. Where's the next vacation to fly off to with the distaff member & 3 (count 'em), 3 carbon-producers? Oh, my bad, it was a "scientific" meeting LOL.
I'm not arguing with you, JF; just asking, really...why doesn't referring by post number work for you? I don't really have you on ignore...some days people get so mean and nasty it's upsetting to me...I know, I know "emotional" female! But I'm proud of that; and I do think I know when do be objective and I KNOW I certainly try to be kind and civil.
I always try to begin or end a post with a compliment, or an explanation of why something is offensive. Some of our younger posters don't understand the historical context of why something they say is hurtful...just in the last two days I had to explain "things" about the Vietnam era and JFK/Irish folk -- but I digress.
Yesterday I felt compelled to tell a poster that his posts using the words "bury" AGW/CC "believers" (that would include "moi") was truly offensive, and that I would flag anyone who used the words "bury" and "kill" any other human beings. But I ended by telling him that I DO like his weather posts.
Anyway, I totally understand that you have strong, albeit "emotional" reactions to some of the reactionary people here and sometimes I think you let it get to you...I do totally understand but I can tell they're trying to trip your trigger, and succeed sometimes (and I can't help but tease about the emotional part).
Hope you can understand...now I've gone on too long!
-------------------------------
Patrap, did somebody rank on Al Gore again?
He is a righteous patriot, but he does have a great sense of humor, and I don't think he'd even mind some of the silly stuff that goes on here.
He and Tipper used to go on the radio with one of our local DJs about once a week, when he was VP. No one made more fun of themselves than they did. I wish people knew how good a sense of humor they have.
I bet that graph has gone through all sorts of statistical fudging! I demand to see the raw data from all the observations so I can calculate for myself if the ice in antartica is really growing or if it is just bad science!
;)
OH, I "get" that. Thanks for helping me understand!
Viewing: 551 - 601
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 — Blog Index