Arctic sea ice loss tied to unusual jet stream patterns
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
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Hutchins and Kleberg up next!
tornado appears to be touching down on the right side, so tornado could grow.
tornado appears quite large.
Not sure if it is all one funnel, since this tornado looks different from the one the spotter saw.
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.
Link
You can clearly see the tornado and funnel, yikes.
I thought it was heading straight for that school..thank goodness..
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.
Another moving through Arlington, heading straight for the DFW Airport!!
I hope everyone is OK
looks like 2 LARGE debris balls.
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.
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.
Tornado Warning
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
134 PM CDT TUE APR 3 2012
TXC113-031915-
/O.CON.KFWD.TO.W.0006.000000T0000Z-120403T1915Z/
DALLAS TX-
134 PM CDT TUE APR 3 2012
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 215 PM CDT FOR EASTERN
DALLAS COUNTY...
AT 133 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONFIRMED A
LARGE AND EXTREMELY DANGEROUS TORNADO. THIS TORNADO WAS MOVING INTO
EASTERN PORTIONS OF THE CITY OF DALLAS. THIS IS A LIFE THREATENING
SITUATION!
THIS IS A TORNADO EMERGENCY FOR THE CITY OF DALLAS! SEEK SHELTER
NOW TO SAVE YOUR LIFE!
THIS WILL CROSS INTERSTATE 45...INTERSTATE 20...AND INTERSTATE 30 IN
THE EASTERN PORTIONS OF DALLAS!
PRECAUTIONARY/PREPAREDNESS ACTIONS...
CARS ARE EASILY TOSSED AND CRUSHED BY TORNADO WINDS. MOTORISTS SHOULD
IMMEDIATELY SEEK SHELTER IN A REINFORCED BUILDING. DO NOT STOP UNDER
BRIDGES OR HIGHWAY OVERPASSES SINCE THEY OFFER NO PROTECTION FROM
TORNADO WINDS.
A LARGE...EXTREMELY DANGEROUS...AND POTENTIALLY DEADLY TORNADO HAS
BEEN CONFIRMED. FLYING AND FALLING DEBRIS IS THE BIGGEST HAZARD IN A
TORNADO. UNDERGROUND OR IN A SAFE ROOM IS THE BEST SHELTER. IF NO
UNDERGROUND SHELTER IS AVAILABLE...GET TO THE CENTER OF A STURDY
BUILDING ON THE LOWEST LEVEL. STAY AWAY FROM WINDOWS AND DOORS. COVER
UP TO HELP AVOID BEING INJURED BY FLYING OR FALLING DEBRIS.
&&
LAT...LON 3298 9664 3298 9652 3280 9652 3262 9668
3261 9674 3266 9683 3298 9677 3299 9665
TIME...MOT...LOC 1833Z 201DEG 23KT 3267 9674
$$
SEVERE WEATHER STATEMENT
NATIONAL WEATHER SERVICE FORT WORTH TX
133 PM CDT TUE APR 3 2012
TXC113-439-031915-
/O.CON.KFWD.TO.W.0005.000000T0000Z-120403T1915Z/
DALLAS TX-TARRANT TX-
133 PM CDT TUE APR 3 2012
...A TORNADO WARNING REMAINS IN EFFECT UNTIL 215 PM CDT FOR EASTERN
TARRANT AND NORTHWESTERN DALLAS COUNTIES...
AT 133 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS CONFIRMED A
LARGE AND EXTREMELY DANGEROUS TORNADO. THIS TORNADO WAS LOCATED NEAR
DALWORTHINGTON GARDENS...MOVING NORTHEAST AT 20 MPH.
THIS IS A TORNADO EMERGENCY FOR PANTEGO AND ARLINGTON!
THE TORNADO WILL BE NEAR...
DALWORTHINGTON GARDENS AND ARLINGTON AROUND 140 PM CDT...
PANTEGO AROUND 145 PM CDT...
GRAND PRAIRIE AND HALTOM CITY AROUND 150 PM CDT...
RICHLAND HILLS AROUND 155 PM CDT...
HURST...NORTH RICHLAND HILLS AND WATAUGA AROUND 205 PM CDT...
BEDFORD AROUND 210 PM CDT...
THIS WILL IMPACT THE FOLLOWING INTERSTATES...
I-35W BETWEEN MILE MARKERS 44 AND 70...
I-20 BETWEEN MILE MARKERS 430 AND 446...
I-30 BETWEEN MILE MARKERS 9 AND 26...
I-820 BETWEEN MILE MARKERS 12 AND 35.
PRECAUTIONARY/PREPAREDNESS ACTIONS...
A LARGE...EXTREMELY DANGEROUS...AND POTENTIALLY DEADLY TORNADO HAS
BEEN CONFIRMED. FLYING AND FALLING DEBRIS IS A SIGNIFICANT HAZARD IN
THIS TORNADO. UNDERGROUND OR IN A SAFE ROOM IS THE BEST SHELTER. IF
NO UNDERGROUND SHELTER IS AVAILABLE...GET TO THE CENTER OF A STURDY
BUILDING ON THE LOWEST LEVEL. STAY AWAY FROM WINDOWS AND DOORS.
COVER UP TO HELP AVOID BEING INJURED BY FLYING OR FALLING DEBRIS.
&&
LAT...LON 3259 9704 3258 9715 3263 9731 3299 9724
3299 9686
TIME...MOT...LOC 1833Z 211DEG 16KT 3268 9718
Many years ago I read Vonnegut's "Cat's Cradle" in which he creates a religion as part of the story. One aspect of the religion is that some times God, for no real reason, just dumps on people.
These events, "pool-pahs" are the wrath of God or "sh!t storm". There's nothing you can do to see them coming, nothing you can do to prevent them, all you can do is to hang on until they are over, clean yourself off, and get on with your life.
Now, I wouldn't suggest you totally overlook what is happened to you. Talk with someone 'wise' and see if you played your hand wrong in the game you were in. Perhaps you encountered a poop-pah, or perhaps you helped shoot yourself in the foot.
But do take the last bit of Vonnegut's philosophy to heart. Clean yourself off and get on with your life.
max daytime heating still to come and the storms are only now in the 10% risk. Watch for more discrete storms.
Not only that but there is another rapidly developing storm that is about 50 miles south of Dallas moving north. It too is beginning to take on rotating characteristics.
They will start firing up fast
Link
After that comes the Arlington storm, with a massive rotation field on TDWR
I hope that southern most storm doesn't start to hook... could get perilously close to downtown Dallas.
They're more concerned with getting out information to the NWS for warnings. Pretty graphics aren't a priority atm.
I've never seen "twin" hook echos like these. My thoughts and prayers are with those on the ground in the path of these. Even the forecaster says "Take shelter to save your life."
NATIONAL WEATHER SERVICE FORT WORTH TX
112 PM CDT TUE APR 3 2012
TXC001-027-035-085-099-113-119-121-139-145-161-19 3-213-217-221-
223-231-251-257-281-289-293-309-331-349-367-379-3 95-397-425-439-
467-497-040100-
/O.CON.KFWD.TO.A.0133.000000T0000Z-120404T0100Z/
TORNADO WATCH 133 REMAINS VALID UNTIL 8 PM CDT THIS EVENING FOR
THE FOLLOWING AREAS
IN TEXAS THIS WATCH INCLUDES 33 COUNTIES
IN NORTH CENTRAL TEXAS
BELL BOSQUE COLLIN
CORYELL DALLAS DENTON
ELLIS FALLS FREESTONE
HAMILTON HILL HOOD
HUNT JOHNSON KAUFMAN
LAMPASAS LIMESTONE MCLENNAN
NAVARRO PARKER ROCKWALL
SOMERVELL TARRANT WISE
IN NORTHEAST TEXAS
ANDERSON DELTA HENDERSON
HOPKINS LEON RAINS
VAN ZANDT
IN SOUTH CENTRAL TEXAS
MILAM ROBERTSON
THIS INCLUDES THE CITIES OF...ARLINGTON...ATHENS...BRIAR...
BRIDGEPORT...BUFFALO...BURLESON...CALVERT...CAMER ON...CANTON...
CENTERVILLE...CLEBURNE...CLIFTON...COMMERCE...COO PER...
COPPERAS COVE...CORSICANA...DALLAS...DECATUR...DENTON...
EAST TAWAKONI...EDGEWOOD...EMORY...ENNIS...FAIRFIELD...
FLOWER MOUND...FORNEY...FORT HOOD...FORT WORTH...FRANKLIN...
GATESVILLE...GLEN ROSE...GLENN HEIGHTS...GRANBURY...
GRAND SALINE...GREENVILLE...GROESBECK...GUN BARREL CITY...
HAMILTON...HEARNE...HICO...HILLSBORO...JEWETT...K AUFMAN...
KILLEEN...LAMPASAS...LEWISVILLE...MARLIN...MERIDI AN...MEXIA...
MIDLOTHIAN...OAK TRAIL SHORES...OAKWOOD...PALESTINE...PLANO...
POINT...ROCKDALE...ROCKWALL...SULPHUR SPRINGS...TEAGUE...TEMPLE...
TERRELL...THE COLONY...VALLEY MILLS...VAN...WACO...WAXAHACHIE...
WEATHERFORD AND WILLS POINT.
$$
Tornado may have returned on the dallas storm.(the eastern one)
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