Arctic sea ice loss tied to unusual jet stream patterns

By: Dr. Jeff Masters , 2:40 PM GMT on April 02, 2012

Share this Blog
39
+

Earth has seen some highly unusual weather patterns over the past three years, and three new studies published this year point to Arctic sea loss as a potential important driver of some of these strange weather patterns. The record loss of sea ice the Arctic in recent years may be increasing winter cold surges and snowfall in Europe and North America, says a study by a research team led by Georgia Institute of Technology scientists Jiping Liu and Judith Curry. The paper, titled "Impact of declining Arctic sea ice on winter snowfall", was published on Feb. 27, 2012 in the online early edition of the journal Proceedings of the National Academy of Sciences. "Our study demonstrates that the decrease in Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation, said Judith Curry, chair of the School of Earth and Atmospheric Sciences at Georgia Tech, in a press release. "The circulation changes result in more frequent episodes of atmospheric blocking patterns, which lead to increased cold surges and snow over large parts of the northern continents."


Figure 1. Arctic sea ice in September 2007 reached its lowest extent on record, approximately 40% lower than when satellite records began in 1979. Sea ice loss in 2011 was virtually tied with the ice loss in 2007, despite weather conditions that were not as unusual in the Arctic. Image credit: University of Illinois Cryosphere Today.


Figure 2. The extent of Arctic sea ice loss in the summer July - August - September period in 2007 was about 1.4 million square miles (3.6 million square kilometers) greater than in 1980, according to the University of Illinois Cryosphere Today. For comparison, the lost ice coverage (orange colors) was equal to an area about 44% of the size of the contiguous U.S., or 71% of the non-Russian portion of Europe.

Summertime Arctic sea ice loss: 40% since 1980
The Arctic has seen a stunning amount of sea ice loss in recent years, due to melting and unfavorable winds that have pushed large amounts of ice out of the region. Forty percent of the sea ice was missing in September 2007, compared to September of 1980. This is an area equivalent to about 44% of the contiguous U.S., or 71% of the non-Russian portion of Europe. Such a large area of open water is bound to cause significant impacts on weather patterns, due to the huge amount of heat and moisture that escapes from the exposed ocean into the atmosphere over a multi-month period following the summer melt. The Georgia Tech study found that Arctic sea ice loss had caused a 20 - 60% weakening of the west-to-east belt of winds circling the pole in recent years, producing broader meanders in the jet stream that allowed it to get "stuck" in place 20 - 60% more often. When the jet stream gets stuck in place for a long period of time, we say a "blocking pattern" has set up. Since the jet stream marks the boundary between cold, Arctic air to the north, and warmer subtropical air to the south, areas on both sides of the jet are subjected to extended periods of unusually warm or cold weather during a blocking episode. Such a blocking pattern began on January 26, 2012 and lasted until February 11, bringing and exceptionally cold and snowy conditions to much of Europe, which lay on the cold side of an elongated loop of the jet stream that got stuck in place. Conversely, most of North America and northern Siberia saw unusually warm temperatures during this period, since they were on the warm side of the jet stream. Lead author Jiping Liu, a senior research scientist in the School of Earth and Atmospheric Sciences at Georgia Tech, added, "We think the recent snowy winters could be caused by the retreating Arctic ice altering atmospheric circulation patterns by weakening westerly winds, increasing the amplitude of the jet stream and increasing the amount of moisture in the atmosphere. These pattern changes enhance blocking patterns that favor more frequent movement of cold air masses to middle and lower latitudes, leading to increased heavy snowfall in Europe and the Northeast and Midwest regions of the United States." The paper concludes: "if Arctic sea ice continues as anticipated by climate modeling results, we speculate that episodes of the aforementioned circulation change will become more frequent, along with more persistent snowstorms over northern continents during winter."


Figure 3. Waiting for the warm-up after a rare snowfall in Italy during the February, 2012 European cold blast. Image credit: wunderphotographer cathykiro.

Two other studies link Arctic sea ice loss to atmospheric circulation changes
"The question is not whether sea ice loss is affecting the large-scale atmospheric circulation...it's how can it not?" That was the take-home message from Dr. Jennifer Francis of Rutgers University, in her talk "Evidence Linking Arctic Amplification to Extreme Weather in Mid-latitudes, presented at December's American Geophysical Union meeting in San Francisco. Dr. Francis presented new research that has just been published in the journal Geophysical Research Letters, which shows that Arctic sea ice loss may significantly affect the upper-level atmospheric circulation, slowing its winds and increasing its tendency to make contorted high-amplitude loops. High-amplitude loops in the upper level wind pattern (and associated jet stream) increases the probability of persistent weather patterns in the Northern Hemisphere, potentially leading to extreme weather due to longer-duration cold spells, snow events, heat waves, flooding events, and drought conditions. Dr. Francis describes her work in a March 5, 2012 post on the Yale environment360 web site.

"Even if the current weather situation may seem to speak against it, the probability of cold winters with much snow in Central Europe rises when the Arctic is covered by less sea ice in summer." That was the opening sentence of a January 26, 2012 press release by a group of European scientists, led by Ralf Jaiser of the Alfred Wegener Institute in Germany. The words proved prescient, because that day marked the beginning of a brutal two-week cold air outbreak over Central and Eastern Europe that killed 823 people and did over $660 million in damage, according to preliminary estimates by insurance broker Aon Benfield. Dr. Jaiser's team, using modeling studies, showed that Arctic sea ice loss weakens upper-level winds over the Arctic in winter, allowing an increased chance of cold air surges over Europe.


Figure 4. Digging out in Maryland after "Snowmageddon" on February 4, 2010. Image credit: wunderphotographer chills.

Why was the winter of 2011 - 2012 so warm in the U.S.?
The winter of 2011 - 2012 in North America was unusually warm--the fourth warmest on record. The cold air spilling out of the Arctic during the winter was confined to Europe, unlike that previous two winters, which were unusually cold and snowy in the Eastern U.S. Obviously, loss of Arctic sea ice is not having the same impact each winter; such factors as El Niño/La Niña, the phase of the 11-year sunspot cycle, and the amount of snow cover in Siberia also have strong influences on the winter weather pattern that sets up. Cold air is less likely to spill out of the Arctic during a solar maximum, as we are now headed towards, so this factor may tend to reduce the odds of getting big cold blasts in the U.S. during the coming two winters. However, cold air may be more likely to spill out of the Arctic in winter due to the decades-long pattern of warming and cooling of Atlantic Ocean waters known as the Atlantic Multidecadal Oscillation (AMO). A 2012 study by NASA scientists found that the warm phase of the AMO (like we have been in since 1995) causes more instances of atmospheric blocking, where the jet stream gets "stuck" in place, leading to long periods of extreme weather. It will be interesting to see how all these factors play out in the coming years. If these three newly-published studies are correct, the U.S. should see more winters like 2010 - 2011 and 2009 - 2010 in coming decades, as Arctic sea ice continues to melt and affect global atmospheric circulation patterns more strongly.

References
Francis, J.A., and S.J. Vavrus (2012), "Evidence linking Arctic amplification to extreme weather in mid-latitudes," Geophysical Research Letters, 21 February, 2012.

Jaiser, R., K. Dethloff, D. Handorf, A. Rinke, J. Cohen (2012), Impact of sea ice cover changes on the Northern Hemisphere atmospheric winter circulation, Tellus A 2012, 64, 11595, DOI: 10.3402/tellusa.v64i0.11595

Liu et al. (2012), "Impact of declining Arctic sea ice on winter snowfall", Proc. Natl. Academy of Sciences, Published online before print February 27, 2012, doi: 10.1073/pnas.1114910109

Jeff Masters

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 678 - 628

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17Blog Index

Quoting ncstorm:


I thought it was heading straight for that school..thank goodness..
Debris ball associated with the tornado nearing Arlington. Very Dangerous Situation.
Member Since: Posts: Comments:
677. Jax82
Truck trailers being thrown like they are toys...its not a weak tornado in Dallas County.
Member Since: Posts: Comments:
Quoting hydrus:
Second tornado heading for Arlington.


That video is of the further east storm near Dallas, the one near heading for Arlington seems to be better organized which is VERY CONCERNING.
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Quoting BobWallace:
Lots of times there are people who volunteer their time who have important connections outside that activity. They have spouses/friends who work in places you might enjoy working. Word of mouth is how a lot of people get their chance


This is exactly how a friend of mine scored their latest set of clients. After being downsized from the 3rd job in two years he started volunteering at a cancer center while trying to get his own company started, ended up getting to know a really well connected woman who now uses his services. Through her network he has expanded his freelance client base. This wasn't on purpose but that's how it worked out. So yes, "who you know" is very important but it's always been this way in a society.
Member Since: Posts: Comments:


looks like 2 LARGE debris balls.
Member Since: Posts: Comments:
Went right over the damn NWS


Member Since: Posts: Comments:
WOOOOWWWWWWWWWW!!!!!!!!
Member Since: August 19, 2006 Posts: 13 Comments: 15707
Look at those truck trailers!
Member Since: Posts: Comments:
I just saw half a building go flying.

I hope everyone is OK
Member Since: Posts: Comments:
669. MTWX
Quoting ILwthrfan:
Tornado is getting much better organized. This could be a big one.

Hutchins and Kleberg up next!

Another moving through Arlington, heading straight for the DFW Airport!!
Member Since: July 20, 2009 Posts: 23 Comments: 1393


you can see exactly where the tornado is and the debris ball is growing, may also be one and the storm out the the east.
Member Since: Posts: Comments:
Is that a MCS west of Dallas?, looks almost like these storms are firing on a weak warm front running along I-20.
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Quoting ILwthrfan:
God, I hope people are taking cover, the tornado over Kennedale is about to track over heavy populated areas.
Second tornado heading for Arlington.
Member Since: Posts: Comments:
Quoting hydrus:
Been on the ground for over 20 minutes. Second tornado on the ground confirmed.


I thought it was heading straight for that school..thank goodness..
Member Since: August 19, 2006 Posts: 13 Comments: 15707
tornado became visible for a second, not too large anymore, sent some sparks flying, outside of the tornado is quite smooth, not sure if that means higher or lower windspeeds.
Member Since: Posts: Comments:
663. Jax82
Here is the link again

Link

You can clearly see the tornado and funnel, yikes.
Member Since: Posts: Comments:
Wow I was looking at The Weather Channel and a lot of debris is flying around. It's not the e biggest or strongest tornado I've seen but it's plenty damaging enough.
Member Since: Posts: Comments:
Quoting ncstorm:
Is it heading for the school?
Been on the ground for over 20 minutes. Second tornado on the ground confirmed.
Member Since: Posts: Comments:
I am watching this on wfaa.com and this is amazing. I hope everyone is ok. It is moving slowwww
Member Since: Posts: Comments:
Quoting RTSplayer:
>
But fine, shoot, let's hear something useful, because I'm stumped at this point in my life, I really am.


Here's a thought...

Seek out at least two organizations in your area that could use some volunteer help and give them ten hours a week of your time. (You pick the numbers.)

Look for opportunities where you could demonstrate your skills (computers/math/whatever), not hanging clothes at the thrift store.

Then be the very best "employee" they have ever had. Always a few minutes early to arrive, a few minutes late to leave, always wash your own coffee cup sort of stuff.

Lots of times there are people who volunteer their time who have important connections outside that activity. They have spouses/friends who work in places you might enjoy working. Word of mouth is how a lot of people get their chance.

Member Since: February 22, 2011 Posts: 0 Comments: 1344
numerous power flashes on dallas tv cameras.

tornado appears quite large.
Not sure if it is all one funnel, since this tornado looks different from the one the spotter saw.
Member Since: Posts: Comments:
God, I hope people are taking cover, the tornado over Kennedale is about to track over heavy populated areas.
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Quoting Jax82:
unbelievable hook echoes towards dallas and ft worth, just out of nowhere.

Looks very bad.
Member Since: Posts: Comments:
Is it heading for the school?
Member Since: August 19, 2006 Posts: 13 Comments: 15707
Member Since: Posts: Comments:
Quoting Jax82:
unbelievable hook echoes towards dallas and ft worth, just out of nowhere.

This looks pretty bad. Debris and power-flashes. The tornado is near schools and a hospital.
Member Since: Posts: Comments:


tornado appears to be touching down on the right side, so tornado could grow.
Member Since: Posts: Comments:
Tornado is getting much better organized. This could be a big one.

Hutchins and Kleberg up next!
Member Since: February 2, 2010 Posts: 0 Comments: 1526
A 3rd tornado warning to the west in the main line. Considerable damage reported and spotter continue to track the tornado.
Member Since: Posts: Comments:
Channel 11 in Dallas using "Tornado Emergency." Large wedge tornado.
Member Since: Posts: Comments:
648. Jax82
unbelievable hook echoes towards dallas and ft worth, just out of nowhere.

Member Since: Posts: Comments:
Quoting Neapolitan:
A weak hook echo headed right into Dallas, and another to the southwest of Fort Worth.

Live TV from WFAA.
They are saying large and dangerous tornado on the ground south Dallas County...Link
Member Since: Posts: Comments:
Large tornado confirmed near Lancaster.

Could barely see the edge of it on the TV
Member Since: Posts: Comments:
Quoting Xyrus2000:


It's not necessarily late melting. Extent depends not only on how much ice there is but also how it is dispersed. Winds have a strong effect on ice extent and what has appeared to be happening over the past couple of years is that the winds around this time of year have become more favorable to "spreading out" the ice. Those graphs are based on areas that show at least 15% coverage, so even "slush" ice will show up as extent.


Not only spreading, but the spreading then allows ice to form in the leads and between the dispersed ice. Spreading increases extent. Subsequent freezing increases area.

I suspect it's easier to freeze the top inches of water if there are blocks of ice floating close by.
Member Since: February 22, 2011 Posts: 0 Comments: 1344

Dallas Love Field DAL Airport flight departure delays

Air traffic control is imposing gate hold and taxi delays on departing traffic ranging from 16 minutes to 30 minutes and increasing.
Member Since: Posts: Comments:


MESOSCALE DISCUSSION 0430
NWS STORM PREDICTION CENTER NORMAN OK
0112 PM CDT TUE APR 03 2012

AREAS AFFECTED...N TX

CONCERNING...TORNADO WATCH 133...

VALID 031812Z - 031945Z

THE SEVERE WEATHER THREAT FOR TORNADO WATCH 133 CONTINUES.

ISOLATED TORNADO THREAT ONGOING -- PARTICULARLY INVOF THE DFW
METROPLEX.

LATEST SURFACE ANALYSIS INDICATES THE WRN EXTENSION OF A W-E OUTFLOW
BOUNDARY IS CURRENTLY LYING OVER THE SRN THIRD OF TARRANT AND DALLAS
COUNTIES -- CONFIRMED BY RECENT VISIBLE SATELLITE IMAGERY. WHILE A
LARGER CLUSTER OF STORMS CONTINUES ACROSS N TX...SMALL SUPERCELL
STORMS MOVING TOWARD -- AND DEVELOPING NEAR -- THE METROPLEX HAVE
PRODUCED A FEW TORNADOES IN THE PAST HALF HOUR TO HOUR -- LIKELY AS
THEY CROSS/INTERACT WITH THE MORE FAVORABLE VORTICITY/LOW-LEVEL
SHEAR ASSOCIATED WITH THE BOUNDARY. THOUGH IN GENERAL EXPECT ANY
SINGLE TORNADO TO BE RELATIVELY BRIEF AS STORMS MOVE QUICKLY NEWD
ACROSS THE BOUNDARY...THE ENHANCED POTENTIAL ACROSS THE METROPLEX
AREA ITSELF SUGGESTS CONTINUED/HEIGHTENED RISK FOR A DAMAGING EVENT.

..GOSS.. 04/03/2012
Member Since: Posts: Comments:
642. Inyo
Quoting IceCoast:
The Weather Channel is live with a tornado on the ground with the Dallas storm.



I just looked at these TWO storms on the radar and they are possibly the nastiest hook echos I've ever seen. If you're in the area please take cover - this could get nasty!
Member Since: Posts: Comments:
looks like a good sized tornado, may have been on the ground for a while.
Member Since: Posts: Comments:
Lancaster going to get hit hard I believe!
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Quoting IceCoast:
The Weather Channel is live with a tornado on the ground with the Dallas storm.
I'v got to go. I hope I don't have Dallas as a headline when I get back.
Member Since: Posts: Comments:
The Weather Channel is live with a tornado on the ground with the Dallas storm.
Member Since: Posts: Comments:
637. MTWX
Quoting RTSplayer:


You've got mail.

Cells are really building in Central TX now!
Link
Member Since: July 20, 2009 Posts: 23 Comments: 1393
Great find on the video Nea!
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Quoting PedleyCA:


thanks for posting that link to that lovely drawing(sic)......
Your welcome. The thread itself is definitely worth a read.
Member Since: Posts: Comments:
Funnel/Tornado on live video:

http://www.wfaa.com/video?id=139367478&sec=553117
Member Since: Posts: Comments:
There is definitely a tornado on the ground in that picture.
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Funnel on the video!
Member Since: February 2, 2010 Posts: 0 Comments: 1526
Wicked hook at 2.10 degree angle velocities.

Texas Storm chasers reported a wall cloud, and those other spotters saw a tornado to start the warning.
Member Since: Posts: Comments:
Quoting Neapolitan:
A weak hook echo headed right into Dallas, and another to the southwest of Fort Worth.

Live TV from WFAA.


Thanks man!
Member Since: October 26, 2011 Posts: 0 Comments: 2651
Quoting GeorgiaStormz:
Lol that might be a debris ball! You don't see 50Dbz out in the middle like that everyday.
Member Since: Posts: Comments:
On tdwr the storm is getting close enough for the hook to dissapear leaving the storm and the funnels possible location.
Wonder if there will be a full ground stop at Dallas Love field
Member Since: Posts: Comments:

Viewing: 678 - 628

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17Blog Index

Top of Page

About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.