Why Southeast Greenland's glaciers have slown down since 2005

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

Share this Blog
4
+

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

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: 913 - 863

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 | 27Blog Index

Quoting StormChaser81:


Here's the Princeton Review's complete list of top party schools:

1. Pennsylvania State University
2. University of Florida
3. University of Mississippi
4. University of Georgia
5. Ohio University
6. West Virginia University
7. The University of Texas at Austin
8. The University of Wisconsin-Madison
9. Florida State University
10. University of California-Santa Barbara
11. University of Colorado-Boulder
12. University of Iowa
13. Union College
14. Indiana University
15. DePauw University
16. University of Tennessee
17. Sewanee: The University of the South
18. University of North Dakota
19. Tulane University
20. Arizona State University


Where is Purdue


HELL YEA PSU BABY!
Member Since: Posts: Comments:
Quoting StormChaser81:


Here's the Princeton Review's complete list of top party schools:

1. Pennsylvania State University
2. University of Florida
3. University of Mississippi
4. University of Georgia
5. Ohio University
6. West Virginia University
7. The University of Texas at Austin
8. The University of Wisconsin-Madison
9. Florida State University
10. University of California-Santa Barbara
11. University of Colorado-Boulder
12. University of Iowa
13. Union College
14. Indiana University
15. DePauw University
16. University of Tennessee
17. Sewanee: The University of the South
18. University of North Dakota
19. Tulane University
20. Arizona State University


Where is Purdue j/k

Better luck next year...lol


Dang, I figured LSU would be on that list... guess not.

Quoting Patrap:
The Rain from the next GOM system now showing up on radar.




Sighs... Im seriously sick of the rain.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
GOM IR Loop




Today and tonight will be fairly quiet outside of winds. Look for
mostly cloudy skies through this time period. The majority of the
cloud cover will be middle and high level clouds. With mostly overcast
skies temperatures will have a hard time rising today. Ll temperatures will not
necessarily be that cool(h925 temperatures around 11-12c). In fact ll temperatures
in this range generally support highs in the middle 60s but with most
of the area starting off in the 40s temperatures will climb slowly today
and will likely have a hard time reaching 60.


Thursday through Friday...this is the focus of the forecast package. As our
disturbance slowly pushes through southern Texas twrds the Gulf, cyclogenesis
will begin in the western Gulf. By Thursday afternoon/early evn we should see a
surface low deepen in the western Gulf while our old cold front will be back
on the way north as a warm front. Decent isentropic lift in the
295/300k levels will likely get light to moderate rain showers as early as
midday Thursday over the coastal parishes but the majority of the rain
will occur during the evn and overnight hours. The surface low will slowly
work east-northeast just south of the la coast and twrds the Florida Panhandle by
late Friday morning. With this track we will stay on the cool side
which will limit the amount of thunderstorms and rain we will see but that said we
will still see strong isentropic lift initially and then some decent
middle level support as our disturbance moves across the northern Gulf. There
could once again be some locally heavy rain as we move under the
deformation zone. At this time it looks like the same areas that
have received the most rain over the past week could very well see
the most rain from this system as well. Another 1-2" of rain looks
possible especially across extreme southeastern la. Rain will exit the
region from west to east late Friday morning and by afternoon all of the
rain should be east of the County Warning Area. /Cab/

Member Since: July 3, 2005 Posts: 421 Comments: 127566
Quoting VAbeachhurricanes:



hey technically were co national champs, never lost to end the season. :p


oh alright :P
Quoting StormChaser81:
Where is Purdue j/k

Better luck next year...lol


LOL we just go down to IU to party
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting tornadodude:


if you played better you would make the tourney ;)



hey technically were co national champs, never lost to end the season. :p
Member Since: Posts: Comments:
Quoting VAbeachhurricanes:


purdue sucks, battle's gonna own you :p


Here's the Princeton Review's complete list of top party schools:

1. Pennsylvania State University
2. University of Florida
3. University of Mississippi
4. University of Georgia
5. Ohio University
6. West Virginia University
7. The University of Texas at Austin
8. The University of Wisconsin-Madison
9. Florida State University
10. University of California-Santa Barbara
11. University of Colorado-Boulder
12. University of Iowa
13. Union College
14. Indiana University
15. DePauw University
16. University of Tennessee
17. Sewanee: The University of the South
18. University of North Dakota
19. Tulane University
20. Arizona State University


Where is Purdue j/k

Better luck next year...lol
Member Since: Posts: Comments:
Quoting VAbeachhurricanes:


yeah just be undefeated when psu beats ya, so we dont get screwed out of the tournament again


if you played better you would make the tourney ;)
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting tornadodude:


:p yeah we suck, we are 9-0 and ranked #4 for nothing haha


yeah just be undefeated when psu beats ya, so we dont get screwed out of the tournament again
Member Since: Posts: Comments:
The Rain from the next GOM system now showing up on radar.


Member Since: July 3, 2005 Posts: 421 Comments: 127566
Quoting alaina1085:

Awesome, I love sports.


yeah ha gotta love 'em!
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting VAbeachhurricanes:


purdue sucks, battle's gonna own you :p


:p yeah we suck, we are 9-0 and ranked #4 for nothing haha
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting tornadodude:


haha yeah and then saturday night I'm going to Indy to watch Purdue play Ball State at conseco fieldhouse link

Awesome, I love sports.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting tornadodude:


haha yeah and then saturday night I'm going to Indy to watch Purdue play Ball State at conseco fieldhouse link


purdue sucks, battle's gonna own you :p
Member Since: Posts: Comments:
Quoting alaina1085:

Eww, saturday morning tests are no fun!! We have our work Christmas part friday night so I would be in no condition for a final the next morning :p


haha yeah and then saturday night I'm going to Indy to watch Purdue play Ball State at conseco fieldhouse link
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting StormChaser81:


Well I hope the rest of your test go alright, When I here final exam, makes me happy to be out of school, but i do miss studying and waiting for the test grade.

Thank you! I graduate in June and I will not miss school! LOL.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting alaina1085:

Yes there are! LOL. It definately takes a certain type of person to do that job, it can be very stressful. I love a challenge tho.


Well I hope the rest of your test go alright, When I here final exam, makes me happy to be out of school, but i do miss studying and waiting for the test grade.
Member Since: Posts: Comments:
Quoting tornadodude:


ha yeah, my last one is saturday morning at 8 :P yuck!! it is EAS 109

Eww, saturday morning tests are no fun!! We have our work Christmas part friday night so I would be in no condition for a final the next morning :p
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting StormChaser81:


My mom does that for a living, she says there millions of codes and she gets the mixed up all the time.

Yes there are! LOL. It definately takes a certain type of person to do that job, it can be very stressful. I love a challenge tho.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting alaina1085:

Lucky! I have my last one tomorrow... its math too, YUCK. Math's my worst subject, otherwise I would have went to school for meteorology as well.


ha yeah, my last one is saturday morning at 8 :P yuck!! it is EAS 109
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting alaina1085:

Medical office specialist. Im going for medical billing/coding.


My mom does that for a living, she says there are millions of codes and she gets them mixed up all the time.
Member Since: Posts: Comments:
Quoting StormChaser81:


Whats your Major?

Medical office specialist. Im going for medical billing/coding.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting tornadodude:


awesome!! I didnt have one today xD

Lucky! I have my last one tomorrow... its math too, YUCK. Math's my worst subject, otherwise I would have went to school for meteorology as well.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
891. IKE
12Z ECMWF....
Member Since: Posts: Comments:
Quoting alaina1085:

Hey Matt,
It was medical terminology final and I think I pretty much Aced it! It was easy.

How did yours go today?


Whats your Major?
Member Since: Posts: Comments:
Quoting alaina1085:

Hey Matt,
It was medical terminology final and I think I pretty much Aced it! It was easy.

How did yours go today?


awesome!! I didnt have one today xD
Member Since: June 28, 2006 Posts: 24 Comments: 8201
Quoting alaina1085:

If im not mistaken, I think Drake is in school during the day. But he is pretty good about getting back with people once he's blogging.
Hopefully that temp will get below freezing and lead to your snow you want :)


im in school too, just got home :) i really hope so...
Member Since: Posts: Comments:
Quoting tornadodude:


how was your final?

Hey Matt,
It was medical terminology final and I think I pretty much Aced it! It was easy.

How did yours go today?
Member Since: August 2, 2006 Posts: 0 Comments: 1240


calling for over a foot!! please happen...

Member Since: Posts: Comments:
Quoting VAbeachhurricanes:
So yesterday the NWS said that this weekend would be 36 degrees all rain, that has dropped to 33 and rain/snow, what are the odds that this trend will continue and they will call for all snow? Drak if your here?

If im not mistaken, I think Drake is in school during the day. But he is pretty good about getting back with people once he's blogging.
Hopefully that temp will get below freezing and lead to your snow you want :)
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting alaina1085:

Lol, I am an adrenaline-junky for sure! I think we all are here.
Oh and guess what... The sun is out here!! Its a rare sighting. lol.


how was your final?
Member Since: June 28, 2006 Posts: 24 Comments: 8201
So yesterday the NWS said that this weekend would be 36 degrees all rain, that has dropped to 33 and rain/snow, what are the odds that this trend will continue and they will call for all snow? Drak if your here?
Member Since: Posts: Comments:
Quoting AwakeInMaryland:

Ahhh, Sister Adrenaline-Junky!
Give the girl her props!
Hope we see you out there!

Lol, I am an adrenaline-junky for sure! I think we all are here.
Oh and guess what... The sun is out here!! Its a rare sighting. lol.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting alaina1085:

Ummm thats a crap load of snow!! I hope this pans out. That would be one amazing photo op!

Ahhh, Sister Adrenaline-Junky!
Give the girl her props!
Hope we see you out there!
Member Since: Posts: Comments:
Seems there is always fly's in our rain chances lately, sighs..
Member Since: Posts: Comments:
Quoting Parkay:


Having lived in San Antonio for 22 years, I can say that Texans have mastered the technique of hydroplaning on perfectly dry roads.

At least im not the only one that has seen that...
Member Since: Posts: Comments:
Quoting 1900hurricane:
12Z GFS madness...


If verified, that would be alot of snow in my area!

Ummm thats a crap load of snow!! I hope this pans out. That would be one amazing photo op!
Member Since: August 2, 2006 Posts: 0 Comments: 1240
The "Fly In The Ointment"

...FL PENINSULA...

SLY LOW-LEVEL JET WILL STRENGTHEN EARLY FRIDAY ACROSS ERN GULF AND
FL PENINSULA IN RESPONSE TO THE APPROACHING SHORTWAVE TROUGH.
CONVECTION WILL LIKELY BE ONGOING WITHIN ZONE OF WARM ADVECTION AND
ISENTROPIC LIFT ACROSS THE PENINSULA EARLY IN THE PERIOD...WITH THE
MORE WIDESPREAD CONVECTION LIKELY NORTH OF WARM FRONT. THE FRONT
SHOULD DEVELOP NWD DURING THE DAY...BUT NWD ADVANCE OF THE MOISTER
WARM SECTOR COULD BE LIMITED BY ONGOING PRECIPITATION. BEST
DESTABILIZATION POTENTIAL SHOULD REMAIN ACROSS SOUTH AND CNTRL FL
WHERE DEWPOINTS WILL RISE INTO THE UPPER 60S SOUTH OF WARM FRONT.
DEEP LAYER WIND AND VERTICAL SHEAR PROFILES WILL STRENGTHEN WITH THE
APPROACH OF THE SHORTWAVE TROUGH. THREAT WILL EXIST FOR ORGANIZED
STORMS INCLUDING SUPERCELLS AND BOWING SEGMENTS WHERE SUFFICIENT
DESTABILIZATION OCCURS. ISOLATED TORNADOES AND DAMAGING WIND WILL BE
THE PRIMARY THREATS. WEAK LAPSE RATES AND LIKELIHOOD OF WIDESPREAD
CLOUDS AND AREAS OF PRECIPITATION REMAIN POTENTIAL LIMITING FACTORS.

Member Since: Posts: Comments:
Quoting Jeff9641:


I live in Longwood and witnessed an F4 tornado move just 9 miles southeast of where I lived. That same tornado killed several of my friends in the Lake Jessup area. This occured at 12:10am.
That is terrible, sorry for your loss.
Member Since: September 27, 2007 Posts: 1 Comments: 20507
869. Ohhh, Skyepony, When Will We Ever Learn?

That's a flashback song/moment, i.e., "Where Have All the Flowers Gone?"

And then there's ...

Well It's One, Two, Three, What Are We Fighting For? ...

5, 6, 7, Open up them pearly gates...

Skye, will you please re-post or WU mail me the 1st hand Copenhagen account you posted the other day. Sorry, I was going to read it later but forgot to note post number...if you still have it...many thanks in advance if it's possible.

BBL.
Member Since: Posts: Comments:
872. 882MB
Yeah Jeff9461 the severe weather hit between 8pm and 2am.
Member Since: Posts: Comments:
This GFS forecast is monumental, IF it materializes as forecasted, the
DFW area of N TX will receive approx. 0.90" of liquid precip, which amounts to about 9-10" of snow!
That would set an all time record at the DFW AP, snarl roads and bring the Metroplex to a STANDSTILL for DAYS!!


The single-digit lows would be near or below record levels. This reminds me of the December 1983 Polar Outbreak that brought 3" of snow and lows in the single digits for about a week!

Member Since: Posts: Comments:
869. Skyepony (Mod)
Police Beat Back Massed Climate Protesters

Article Tools Sponsored By
By TOM ZELLER Jr. and JOHN M. BRODER
Published: December 16, 2009

COPENHAGEN — Police officers used pepper spray and wielded batons on Wednesday to beat back hundreds of demonstrators outside the global climate meeting here, as a police spokesman said 250 people had been arrested.

Police clash with protesters at a roadblock near the venue of the United Nations Climate Change Conference in Copenhagen on Wednesday.

The police tried to disperse the chanting, drum-beating protesters who had marched from a train station about a mile away to try to make their way to the Bella Center, where representatives from nearly 200 countries are meeting to try to reach an accord on climate change. A group of 50 to 100 delegates emerged from the convention center, seeking to meet with the protesters, but they, too, were driven back by the police. more here
Member Since: August 10, 2005 Posts: 161 Comments: 37359
Quoting Parkay:


Having lived in San Antonio for 22 years, I can say that Texans have mastered the technique of hydroplaning on perfectly dry roads.

LOL! (And accurate!)
Member Since: Posts: Comments:
Quoting tornadodude:


thats true, having lived in north east Texas, I witnessed many drivers having problems in ice


Having lived in San Antonio for 22 years, I can say that Texans have mastered the technique of hydroplaning on perfectly dry roads.
Member Since: Posts: Comments:
865. 882MB
THERE WERE ALSO 2 TORNADOES IN KENDALL SOUTH MIAMI DADE.
Member Since: Posts: Comments:
Quoting AwakeInMaryland:


Yeah, but mine's raunchier, lol!
Suggest you use Grothar's on your term paper, esp. if prof. is a woman!

Though think she'd agree with me, secretly or not -- most handsome -- my best friend said after high school (indiscriminate crushes), my "type" became obvious, lol.

Dark and handsome -- and brainy don't hurt none, either.

OHHHH, speaking of, HI AGAIN, Bordonaro and Grothar!!

Craig Ferguson WAS AMAZING last night! One-thousandth episode, and pulled out all the stops on the puppets and bits! I have to watch again on Hulu or whatever, because I was distracted by Blog.

Song from "Phantom of the Opera" by the Count and some excellent musical assistance was great, and actually touching... then again, I'm easily touched...just plain "touched!"


Watched the Craig Ferguson opening videos from last night! Hilarious!!
Member Since: Posts: Comments:
863. 882MB
I still remember back in February 2,1998 during EL NINO SEASON, THERE WAS A HUGE LOW PRESSURE SYSTEM THAT DEEPENED IN THE GULF AND BROUGHT 100 MPH WIND GUST OVER MUCH OF SOUTH FLORIDA AND 3 TO 4 INCHES OF RAIN FELL.LOOKS LIKE THIS WILL BE AN INTERESTING WINTER SEASON HERE IN SOUTH FLORIDA FOR THE PAST 3 WEEKS MOST OF THE LOW PRESSURE SYSTEMS HAVE DEVELOPED OVER THE GULF AND THERE HAS ALSO BEEN A VERY ACTIVE SUBTROPICAL JETSTREAM ALL INDICATIVE OF A MODERATE TO STRENGTHENING EL NINO.
Member Since: Posts: Comments:

Viewing: 913 - 863

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 | 27Blog 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.