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
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You're very welcome!
And Semper Paratus to snowy Orca-land! Hmm, do they say that in Canada? "Semper Parat-US, keep them well and far away from Canada!"
That is still how I read it...
More than a little offensive, too.
REMINDER: 13-0, 13-0, 13-0
It's ALL Good!
Things are best seen in the Light of truth.
13-0,by the way.
Who Dat?
We dat...
Heres a Lil "Wah,Wah" fer yas too.
I still love lightning and thunderstorms! We used to go out and PLAY in them in our swimsuits when we were kids...lived to tell about it, too (despite the stupidity)...hmm, maybe that explains the major hair frizz, along with the humidity.
Have a good afternoon, all. I have to attend to post-weekend Monday chores. :{
There was a great post yesterday of an extended car-crash event; excellent testosterone rush; scary! Sorry for those involved, but didn't look like anyone was truly hurt (hope); more like car-crash rodeo.
Given all the warming trend data and that it's still not winter by the calendar, how does such a phenomenon occur?
In TX when you play in a thunderstorm, in the summer, its fun to just stand out and get soaked through and through. I have done that a few times after a LOOOONNNGGGGG heat wave breaks and the first rain after about 1 or 2 months (no joke, it has gone 84 days in 1 heat wave without rain). My wife used to think I was insane. Me and the 5 kiddoes used to get soaked and walk inside with out dry towels and freeze our hiney off, then get changed into dry clothes.
Go easy there on that vacuum cleaner, don't vacuum up the lil' Pomeranian
I don't know about you, but I had zero interest in frats. None whatsoever.
Partly related to a complete lack of spare time and money, but not entirely.
The coldest weather I experienced was a balmy -8F in Buffalo, NY in early 1980. The wind chill was about -40F. With 2 pairs of socks, long johns bottoms, 2 pairs of pants, a t-shirt, long john uppers, a heavy cotton shirt, a parka, scarf and a face mask, mittens, wearing my hood, my whole body was just freezing!!
Yup...the feeding frenzy has begun.
Once went skiing in UP Michigan. Low of -5 F, high of 2 F...still had fun, but, yeah, it was chilly.
(Err, UP = Upper Peninsula, for most of you southerners)
Areal Flood Advisory, Flash Flood Watch
Statement as of 11:04 AM CST on December 14, 2009
The National Weather Service in New Orleans has issued an
* Urban and Small Stream Flood Advisory for the following parishes...
Jefferson... Orleans... Plaquemines... St. Bernard... St. Charles
... St. James... and St. John The Baptist Parish.
* Until 100 PM CST
* at 1058 am CST National Weather Service meteorologists detected several
clusters of thunderstorms moving northeast towards New Orleans and the
surrounding areas. These storms are moving rather quickly but will produce
brief heavy rainfall which will lead to minor flooding. Expect rainfall
amounts up to 1 inch.
Precautionary/preparedness actions...
Most flood deaths occur in automobiles. Never drive your vehicle into
areas where the water covers the roadway. Flood waters are usually
deeper than they appear. Just one foot of flowing water is powerful
enough to sweep vehicles off the Road. When encountering flooded
roads make the smart choice... turn around... dont drown.
Excessive runoff from heavy rainfall will cause elevated levels on
small creeks and streams... and ponding of water in urban areas...
highways... streets and underpasses as well as other poor drainage
areas and low lying spots.
Lat... Lon 2957 8995 2966 9015 2969 9016 2973 9030
2990 9049 2993 9074 3006 9092 3018 9049
3030 9033 3029 9031 3017 9042 3006 9037
3003 9018 3005 9001 3014 8989 3011 8980
3016 8962 3002 8983 2995 8981 2987 8964
...at least until CAGW makes that area a subtropical paradise! LOL
Christmas Music playlist Link
I have to agree what a waste of time and money. Plus when you think about it, thats sad you have to buy friends and when it comes don to it there still not your friend and will run over you if they had the chance.
I hope the more-than-2-inches-per-hour cells skip the city...that will not be pretty if it happens.
Heavy Rains,maybe a Inch or more per hour rate.
Gonna be a long afternoon commute if it continues.
Try this to see what the hurricane thing is about.
Go get an empty one gallon metal can like you would get from Ace Hardware.
Make sure it is clean and dry.
Put two tablespoons of water into the can.
Place the can on the stove and turn the heat to high, leaving the top until the water is at a full roiling boil and steam is pouring out of the top.
Now put the top on the can, making sure it is real tight. Placing it back on the stove burner.
Wait until the can starts to bulge out on the sides and then remove the can from the stove and take the can to the sink and pour a bunch of cold water over the can and watch what happens.
Nope, not telling.
All I will say is that they use the same principle in steam locomotives.
BTW...The demonstration was on Mr Wizard or one of the other TV shows about science for kids.
How's everyone doing?
We have a bad T cell over us in Ascension at the moment. Moving 30 mph tho.
We have a flood warning right now. We still havent dried out since that 5 inches we got last monday! We had a grave yard with graves literally floating around!
I agree with your function-description.
But, the Bulletin of the AMS had an article a couple of months ago with a statistical study of lightning fatalities from 1959 to 2003 that showed that FL does have a lot of lightning fatalities, but not number one per capita or per state square miles.
New Jersey wins the per square mile award for lightning deaths.
By population?
The top 10 (1 to 10):
Wyoming
New Mexico
Arkansas
Colorado
Florida
Mississippi
Utah
Arizona
Louisiana
Montana
And the number one metro area in terms of number of lightning deaths?
Miami, followed by New York, Chicago, Tampa, Houston, Denver, Orlando, Philly, New Orleans, Washington DC.
Seems like it is as much about population and outdoor activities, as it is the weather...
Full article here: http://ams.allenpress.com/perlserv/?request=get-abstract&doi=10.1175%2F2009BAMS2765.1
There he is. Funny lady, a.k.a. AwakeInMaryland was losing sleep worrying about you (Hence, Awake...)
You mount a monitor and keyboard to the underside of bedpan so you can visit? Or are you somewhat upright? (the latter, I hope!)
Well, the fast-mover part is bad for potential wind damage, but wunderful news for the street flooding potential.
One of the main reasons why I'm skeptic on the whole AGW issue. If you question their conclusions, you get attacked. It's been that way for years. I know the planet got warmer, during the 90's especially. How much of it is
man-made is very debateable.
I'm about as alright as I can expect to be; I am 4 weeks post surgery (give or take a day or two), my sciatic paibn is gone, but man I thought I knew what a back spasm was...I'm a little weak; I try to walk one to two miles a day and wear the back brace as little as possible (per doctors instructions). I must look funny though, wandering my sudivision using my walker...
I'll be here more regularly now that sitting up for long periods of time isn't that much of an issue and I am back at work on a limited schedule this week and likely full time starting next week
All I can say is that it's great to be back!
Sounds like your in good spirits! Glad all is well Flood.
NASA, December 2008
350ppm was the short answer.. Eye opening graph..
Flood, you had us worried. I hope this will in no way prevent you from keeping us line when we misspeak! Glad you are finally on the mend.
I'm sorry if I caused anyone any worries (Awake); I'm fine as can be expected, and in fact, my docs say I'm better than they expected me to be...I tend to take PT orders very seriously
Okay, I'm out for a short; I have a few errands to run and I have to kick a couple of people in their nether regions as they seemed to think that since I was out of office they had a vacation...LOL
By the way, Pat, stay dry...looks like you're getting way too much rain and far too little drainage about now
BBL, y'all
If someone is banned from the blogs the content usually disappears. If banned from this blog & their blog is intact~ once in it, on the right side you can search by month/yr.
Jerry brings a certain Flair here we've missed.
Please feel free to wish Patrap Jr. a Happy 17th B-day today.
South Bend Indiana, early 90's. The wind chill I remember was -50 and the actual low was around 20 below. I had to get up at 5am that morning for school. The football coach wanted all of us to take track so we would stay in shape over the winter, ack. I had a hard time taking a breath without a scarf over my mouth. Brrrrrrrr
Amazing....
The hearing was supposed to focus on the latest in global warming scientific findings. Lubchenco even attempted a high school chemistry lesson with two quick experiments at the witness table. Donning one rubber glove, she demonstrated how adding carbon dioxide to water made it more acidic and said that is what's now happening in the world's oceans. Then she put chalk in acidic water compounds and showed it dissolving a bit, to demonstrate what will happen eventually to vital sea life.
But her bubble-inducing experiments were ignored in favor of the more explosive e-mails.
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