Why Southeast Greenland's glaciers have slown down since 2005

By: Dr. Jeff Masters , 3:57 PM GMT on December 15, 2009

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I'm in San Francisco for the annual meeting of the American Geophysical Union, the world's largest gathering of climate scientists. I saw ten or so great talks yesterday (and five really boring ones!) Here's a summary of the the most interesting talk I heard yesterday:

If you plan on owning ocean front property after the year 2050, you should pay close attention to the glaciers In Greenland. Greenland holds enough ice to raise global sea level by over 20 feet (6.5 meters), should its ice cap completely disintegrate--though such an event would likely take centuries to occur. Still, should the climate warm 2°C or more this century, partial melting of the Greenland Ice Sheet could readily raise global sea level by a meter or more by 2100. That's why scientists reacted with concern during 2003 - 2005, when all of the glaciers in southeastern Greenland accelerated in synchrony to speeds 30% to 210% faster than they had flowed in 1996. As they sped up, the glaciers began dumping huge amounts of ice into the ocean off the coast of southeast Greenland, more than doubling Greenland's contribution to global sea rise, to .57 mm/year. Would the glaciers keep accelerating, bringing about an increasing disintegration of the Greenland Ice Sheet? Nobody knew, since computer models of glacial dynamics were (and still are) in a primitive state.


Figure 1. Helheim Glacier in southeast Greenland, in three images captured in 2004, 2005, and 2006. The glacier accelerated significantly in 2005, and the face of the glacier retreated 5 km inland (middle frame) compared to 2004. However, by the summer of 2006, the acceleration ceased, the the glacier returned back to its 2004 position. Image credit: Ian Howat, University of Washington.

Well, it turned out that 2005 was the peak of the glacial acceleration event. The glaciers in southeast Greenland have returned to where they were eight or nine years ago--still causing a net loss of mass that is raising global sea level, but not as fast as in 2003 - 2005. In a talk titled, "Ocean regulation of glacier dynamics in south-east Greenland and implication for ice sheet mass changes", Tavi Murray and colleagues from the UK's Swansea University presented a plausible theory for why this strange synchronous speed-up and slow-down occurred. Using satellite, aircraft, and surface observations, the researchers found that air temperatures in the region did not vary much over 2003 - 2005 (Figure 2). Thus, a major increase in temperature could be ruled out as the cause of the glacier surge. However, study of the ocean temperatures near the coast revealed strong clues that ocean currents were responsible for the surge.

Figure 2. Ocean currents off the east coast of Greenland feature the cold East Greenland Coastal Current flowing north to south (white arrows) and the warm Irminger Current flowing south to north (red arrows). Image credit: Arctic Climate Impact Assessment.

Ordinarily, the southeast coast of Greenland features a cold water current flowing north to south, called the East Greenland Coastal Current (EGCC). Much of the cold water for this current is supplied by melting of the 14 glaciers in southeast Greenland that empty into the sea (two of these glaciers, Kangerdlugssuaq and Helheim, represent 35% of east Greenland's total glacial discharge). A few hundred kilometers offshore, a warm water current called the Irminger Current flows the opposite direction, bringing warm water from the North Atlantic northward. In 2003, it happened that weather conditions over Greenland brought an unusually low amount of run-off of precipitation. With little new mass pushing the glaciers seaward, the glaciers responded by greatly reducing the amount of ice they dumped into the ocean by the shore. As a result, the East Greenland Coastal Current slowed down and warmed, which allowed the warm Irminger Current to advance towards the coast, warming the coastal waters even more. All that warm water near the coast began melting the glaciers where they reached the sea, causing the glaciers all along the southeast coast of Greenland to accelerate and rapidly thin between 2003 - 2005. By 2006, the thinning glaciers had dumped so much new ice into the ocean near the coast that the waters cooled and the East Greenland Coastal Current re-established itself. This cooled the glaciers at their marine termination points and slowed down the glacial surge, putting the glaciers back where they had been before 2003. This is a classic example of a negative feedback process--a change in weather conditions which generates a response, but the response creates conditions that tend to dampen the response.


Figure 3. Average temperatures for the only station in southeast Greenland with a century-long temperature record, Angmagssalik (called Ammassalik on the map in Figure 2). Temperatures in southeast Greenland during the 1930s and 1940s were similar to today's temperatures, suggesting that glacial surges like we witnessed in 2005 may have also occurred in the 1930s and 1940s, before we had monitoring capability. Image credit: NASA Goddard.

Commentary
As I commented in my previous post, 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 positive feedback loop was a bad news surprise that our climate models did not predict. Now we have evidence of a good news surprise that no model predicted--a negative feedback loop that acts to keep the southeast portion of Greenland's Ice Sheet from runaway glacial acceleration. We can expect many more surprises--good and bad--over the coming decades, as our climate responds to the huge shove human activities are giving it.

Ricky Rood in Copenhagen
Our Climate Change expert, Dr. Ricky Rood, is in Copenhagen for the COP15 climate change treaty negotiations. His latest post, called Have you no sense of decency, sir, at long last? makes for very interesting reading on how the U.S. is "wasting its intellect and time on disruptions designed to play to people at home".

Next post
I'll have another post from the AGU meeting Thursday or Friday this week.

Jeff Masters

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Quoting PcolaDan:





ohhh I like that one... that would be a good avatar for shep
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Quoting Bordonaro:


Thanks! However I have made more mistakes than I have hair on my head, however, and I have a full head of hair at 48+ yrs of age.

Lying and being hateful is a sincere waste of time. I find it so much easier to tell the truth than to lie. Do I lie, yes, I am human, BUT I try hard not to do so! As far as hatred goes, I have no patience for it!

Hemlock killed Socrates! Hatred/bitterness kills you from the inside out.


I don't believe this quote is too far from what we have been witness to on the blog, and its application may be applied to other situations as well.

Passionate hatreds can give meaning and purpose to an empty life. These people haunted by the purposelessness of their lives try to find a new content not only by dedicating themselves to a holy cause but also by nursing a fanatical grievance. A mass movement offers them unlimited opportunities for battle.- Eric Hoffer.
Member Since: July 17, 2009 Posts: 71 Comments: 27210
Quoting theshepherd:

Go to bed...
:)


watch it.. I saved that remark of yours about wanting snow....
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Quoting Orcasystems:


SNOW... FLORIDA...CHRISTMAS...
Man, just what I asked Santa for... happy dance happy dance :)


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See ladies, I knew man wasn't a practice run and woman the final product.

Dan, hmmm,
ok, G-d don't make mistakes --
but there are some really good improvements?

Grothar, right again!


Member Since: August 19, 2008 Posts: 32 Comments: 1918
For Nana...Rudolph trailer:

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Quoting Orcasystems:


SNOW... FLORIDA...CHRISTMAS...
Man, just what I asked Santa for... happy dance happy dance :)

Go to bed...
:)
Member Since: September 11, 2008 Posts: 9 Comments: 10167
Orca, I love TX, it's my adopted home, been here almost 30 yrs! Racial discrimination is nothing like it was in the 1950's and 1960's!

However, I admit, SADLY, it is quite prevelant in some areas of TX, even in what's almost 2010.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
554. Skyepony (Mod)
I may still be mourning quikscat but ran across this. Fairly related to Master's well wrote entry. In 2005 Quikscat found a large melt & refreeze occurring in Antarctica in ways thought impossible before~ too high, way inland. NASA article

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Quoting GeoffreyWPB:
Drak...if you are lurking...is there a chance of snow flurries in north or central Fla. Christmas Day?


SNOW... FLORIDA...CHRISTMAS...
Man, just what I asked Santa for... happy dance happy dance :)
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Quoting Grothar:


Bordonaro does it well, Awake. Not someone I would want to mess with. That is why I enjoy his blogs, straight-shooter!


Thanks! However I have made more mistakes than I have hair on my head, however, and I have a full head of hair at 48+ yrs of age.

Lying and being hateful is a sincere waste of time. I find it so much easier to tell the truth than to lie. Do I lie, yes, I am human, BUT I try hard not to do so! As far as hatred goes, I have no patience for it!

Hemlock killed Socrates! Hatred/bitterness kills you from the inside out.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
I have to say, not sure if it was the luck of the draw, or just the way Canadians think different... I have not seen much in the way of racism here.

I have seen lots in my travels around the world, and it surprises me that people put up with it?
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Quoting Bordonaro:


Simply amazing if that does come to pass! When had 2 " of sleet on Thanksgiving in 1992 or 1993. Snow in DFW on Christmas would be an awesome miracle! And I believe it may come to pass!!


oh my, I remember that....

Member Since: June 28, 2006 Posts: 25 Comments: 8360
Quoting Orcasystems:


Aww man, now I have to read all the way back and find out what you did :)


Oh, Orca, what I did...scroll scroll back to #507.

REWRITE: Bordonaro is strong and good and kind.
Nope, I'm not getting kickbacks (wish), LOL.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting Bordonaro:


I know God knew what he was doing when he made man!


Nope not gonna do it. Don't care how good a setup line this is.

errr errrr

NOOOOOO Don't give in. Don't do it.

RESISTANCE IS FUTILE!!!!!

AAAAHHHH THE AGONY

Deeps breaths, in ... out ... in ... out.

Whew, much better now. :)










See ladies, I knew man wasn't a practice run and woman the final product.
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Parts of Texas...yes.
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Drak...if you are lurking...is there a chance of snow flurries in north or central Fla. Christmas Day?
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Quoting Orcasystems:


Aww man, now I have to read all the way back and find out what you did :)

# 516. I just stood up as a growing child, knowing from the heart what was right!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting btwntx08:

and its on christmas btw ;)


Simply amazing if that does come to pass! When had 2 " of sleet on Thanksgiving in 1992 or 1993. Snow in DFW on Christmas would be an awesome miracle! And I believe it may come to pass!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
541. amd
Quoting AwakeInMaryland:
Thank you, Bordonaro, for being you, and strong and good and strong. That stuff shouldn't have happened to you; no doubt your grandpa loved you but was misguided.
My son tasted some soap...!

adm, thanks for keeping your head when I was losing mine. Something about that entire exchange just totally tripped my trigger...all resolutions to be tolerant and kind just went flying out the window!



awake, thanks for the words

IMO, alleging that someone is racist without actually having the upfront proof is incredibly incendiary and irresponsible. However, I have been here since august 2005 and actually have seen quite a bit worse than that on this board.

Personally, that I why I very rarely discuss topics other than the immediate weather on these boards. Too many people can pull too many things out of context, and quite frankly, I have better uses of my time than to get dragged into all of that.
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Quoting AwakeInMaryland:
Thank you, Bordonaro, for being you, and strong and good and strong. That stuff shouldn't have happened to you; no doubt your grandpa loved you but was misguided.
My son tasted some soap...!

adm, thanks for keeping your head when I was losing mine. Something about that entire exchange just totally tripped my trigger...all resolutions to be tolerant and kind just went flying out the window!



Aww man, now I have to read all the way back and find out what you did :)
Member Since: Posts: Comments:
Quoting AwakeInMaryland:
Thank you, Bordonaro, for being you, and strong and good and strong. That stuff shouldn't have happened to you; no doubt your grandpa loved you but was misguided.
My son tasted some soap...!

adm, thanks for keeping your head when I was losing mine. Something about that entire exchange just totally tripped my trigger...all resolutions to be tolerant and kind just went flying out the window!



People in Africa and India have dark skin to protect them from the strong sun that beats down directly on them several months a yr. People in China and SE Asia have a yellow/brown skin color. Other parts of the world, the further north you go, generally the lighter your skin pigmentation.

There are bad white, yellow, red, brown and black people! I know God knew what he was doing when he made man!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting btwntx08:


maybe a flurries there


You are correct. Not going to happen.
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Quoting AwakeInMaryland:
Thank you, Bordonaro, for being you, and strong and good and strong. That stuff shouldn't have happened to you; no doubt your grandpa loved you but was misguided.
My son tasted some soap...!

adm, thanks for keeping your head when I was losing mine. Something about that entire exchange just totally tripped my trigger...all resolutions to be tolerant and kind just went flying out the window!



Bordonaro does it well, Awake. Not someone I would want to mess with. That is why I enjoy his blogs, straight-shooter!
Member Since: July 17, 2009 Posts: 71 Comments: 27210
Iceberg floats past New Zealand

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Thank you, Bordonaro, for being you, and strong and good and kind. That stuff shouldn't have happened to you; no doubt your grandpa loved you but was misguided.
My son tasted some soap...!

adm, thanks for keeping your head when I was losing mine. Something about that entire exchange just totally tripped my trigger...all resolutions to be tolerant and kind just went flying out the window!

Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting btwntx08:
00z gfs builds a 1048 mb high in canada brings cold down to the gulf coast


I am smelling snow already, over the internet, wafting out of my laptop speakers :0)!!

Member Since: August 25, 2009 Posts: 20 Comments: 6785
No way cold enogh Jeff:

Local Text Forecast for
Orlando, FL

Dec 15 Tonight
Some clouds. Low 66F. Winds NNW at 5 to 10 mph.
Dec 16 Tomorrow
Cloudy with a few showers. High 73F. Winds NNE at 15 to 25 mph. Chance of rain 30%.
Dec 16 Tomorrow night
Cloudy with a few showers. Low 63F. Winds NNE at 10 to 20 mph. Chance of rain 30%.
Dec 17 Thursday
Occasional showers possible. Highs in the low 70s and lows in the mid 60s.
Dec 18 Friday
Thunderstorms. Highs in the mid 70s and lows in the low 60s.
Dec 19 Saturday
Considerable cloudiness. Highs in the low 60s and lows in the upper 40s.
Dec 20 Sunday
Mostly Cloudy. Highs in the low 60s and lows in the low 40s.
Dec 21 Monday
More clouds than sun. Highs in the low 60s and lows in the low 40s.
Dec 22 Tuesday
A few clouds. Highs in the low 60s and lows in the upper 40s.
Dec 23 Wednesday
Sunshine. Highs in the mid 60s and lows in the upper 40s.
Dec 24 Thursday
Plenty of sun. Highs in the upper 60s and lows in the mid 50s.
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HELLO!
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Quoting amd:


I think a lot of that "discussion" a couple of pages ago btw spathy and the other fellow, which sparked the racial allegation, was more about an old feud from some of the other WU blogs. I think it was much ado about nothing, and instead was there to spread drama to Dr. Masters's blog.

On a weather related note, I'm all for heavy snow on the east coast. I just want it to arrive AFTER i fly back into Philly to visit family and old friends.


I pray and hope the "Big Boss" allows you a safe trip, and as soon as you get home, "WHITEOUT"!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Member Since: June 28, 2006 Posts: 25 Comments: 8360
520. amd
Quoting Bordonaro:


I used to get my butt beat as a child for NOT being racist and hateful, as I was taught, by my ignorant grand dad!

I used to beat my kiddos butts if they used ANY racial epitaphs


I think a lot of that "discussion" a couple of pages ago btw spathy and the other fellow, which sparked the racial allegation, was more about an old feud from some of the other WU blogs. I think it was much ado about nothing, and instead was there to spread drama to Dr. Masters's blog.

On a weather related note, I'm all for heavy snow on the east coast. I just want it to arrive AFTER i fly back into Philly to visit family and old friends.
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Copenhagen, New York (PWS)
Updated: 4 sec ago
Overcast
23.5 °F
Overcast
Windchill: 24 °F
Humidity: 65%
Dew Point: 13 °F
Wind: 3.8 mph from the West
Wind Gust: 6.3 mph
Pressure: 30.10 in (Rising)
Visibility: 10.0 miles
UV: 0 out of 16
Clouds:
Overcast 5500 ft
(Above Ground Level)
Elevation: 1164 ft
Member Since: June 28, 2006 Posts: 25 Comments: 8360
Copenhagen, DN (Airport)
Updated: 12 min 53 sec ago
37 °F
Mostly Cloudy
Windchill: 28 °F
Humidity: 87%
Dew Point: 34 °F
Wind: 18 mph from the WSW
Pressure: 29.83 in (Steady)
Visibility: 6.2 miles
UV: 0 out of 16
Clouds: Few 1500 ft
Scattered Clouds 3700 ft
Mostly Cloudy 7100 ft
(Above Ground Level)

Member Since: July 17, 2009 Posts: 71 Comments: 27210
Quoting AwakeInMaryland:
Jesus...

398. stormobserver 1:57 AM GMT on December 16, 2009
Spathy is just a racist crank who got banned for 96 hours for posting racist pictures last summer


399. spathy 2:01 AM GMT on December 16, 2009
#398
Ok


OK??? OK???

NO, NOT OKAY!!!!


Sometimes leaders have to listen, and sometimes leaders have to lead, and sometimes we need to get new leaders.

Otherwise, most of the U.S. population wouldn't even be able to vote out the leaders who don't listen, can no longer lead, don't wish to, or who have lost their way.




I used to get my butt beat as a child for NOT being racist and hateful, as I was taught, by my ignorant grand dad! I am not a racist, and I cannot stand that type of IGNORANCE!!

I used to beat my kiddos butts if they used ANY racial epitaphs!!

Racism stirrs hatred and it in NEVER appropriate, EVER!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
515. xcool
new update come soon
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Quoting amd:


I think it is likely that due to the El Nino induced sub tropical jet, a low coming out of the gulf, and a piece of the polar vortex diving down from Canada, a big storm will form in the Western Atlantic on sunday and monday.

The only question is this: Does the storm form close enough to the coast and give heavy snow from Raleigh to Boston, or does the storm bomb out well to the se of cape cod, and lash the Canadian Maritimes with substantial wind and snow, while leaving most of the eastern US cold and dry



I hope that the Carolina's, the Mid Atlantic, The NE and New England have a beautiful 6-20" late week snow!! We'll send our friends in the Canadian Maritime a nice pre Christmas Blizzard :)!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Excellent post Doc. Thanks.

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

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