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: 363 - 313

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 Patrap:



..shhh .

Lotsa folks dont know what existed on the Land below the Superdome, where before they poured the slab,they drove pilings for a year..

The answer is very..creepy.


SHH! They mentioned it during Katrina on our local news! Starts with a G.
Member Since: July 17, 2009 Posts: 63 Comments: 23739
Deep South? it's a brand of peanut butter round these parts.

We just don't get snow here in Jax. Yep, I'm a denialist!

would LOVE to be proven wrong, tho... :)
Member Since: Posts: Comments:
361. unf97
Quoting aquak9:
hello unf

dau waiting SO IMPATIENTLY on grades...

and how DEEP is this deep south ya'll speak of?

Pat- gather the animals, two by two...


Good evening aquak!

Well, the GFS for almost the last week has been consistently outlining a possible snow event deep down into the South and parts of the Gulf Coast. Now, I have my own rule of thumb to not go past 7 days on any forecast. However, if the GFS model keeps depicting this by week's end, then I will start paying closer attention to it. But, anticipate many changes to the models of course.

I will say that the pattern is definitely changing to a more colder, amplified trough developing late this weekend into next week across the Eastern third of the ConUS.
Member Since: Posts: Comments:
Quoting eyesontheweather:
Did not find an answer. only verified that the ice flow and the rift were located in the samme areas but from different era
I apologize, if I knew how to link it I would.
Member Since: Posts: Comments:
We may have to do that seem aquak9..

We've also been keeping one eye on the Saints and 2 on the ol Snow,thingee map-of-jig forecast Blue,white stuff,colored,real squeaky close post's from xcool.
Member Since: Posts: Comments:
Quoting Patrap:



..shhh .

Lotsa folks dont know what existed on the Land below the Superdome, where before they poured the slab,they drove pilings for a year..

The answer is very..creepy.

*Raises hand* I know I know!!
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting StSimonsIslandGAGuy:
I thought undefeated Saints were historic already :P


Touche!
Member Since: Posts: Comments:
Quoting GeoffreyWPB:
My dream is a Super Bowl between the undefeated Saints and Colts! Historic!!!!



..shhh .

Lotsa folks dont know what existed on the Land below the Superdome, where before they poured the slab,they drove pilings for a year..

The answer is very..creepy.
Member Since: Posts: Comments:
awww...SSI...

man I could tell some stories about that night. Was the front driver of a caravan of eight, to cross a three mile long bridge, before it closed. Troopers followed us.

was like magic, like a once-in-a-lifetime dream.
Member Since: Posts: Comments:
The small but mighty powerful Severe Tropical Cyclone Laurence








Member Since: Posts: Comments:
Evening Grothar. I did not see your post. Of course I would of put it up.
Member Since: Posts: Comments:
350. unf97
I forgot to say good evening to everyone in thw WU blog!

Member Since: Posts: Comments:
hello unf

dau waiting SO IMPATIENTLY on grades...

and how DEEP is this deep south ya'll speak of?

Pat- gather the animals, two by two...
Member Since: Posts: Comments:
Miami NWS has been saying it would stall over the Straits for the last few days but now says this:
SO WILL HAVE TO CONTINUE TO MONITOR
THE PROGRESS OF THE POTENTIAL FOR DEVELOPMENT OF THE SURFACE LOW
ACROSS THE NORTHERN GULF OVER THE NEXT COUPLE OF DAYS BEFORE WE
WILL HAVE MORE CERTAINTY ABOUT THE POTENTIAL IMPACTS FOR SOUTH
FLORIDA.

When read w/ GeoffreyWPB's post at 341, it sound like the Gulf low may be tracking further south than previously thought.
Member Since: Posts: Comments:
My dream is a Super Bowl between the undefeated Saints and Colts! Historic!!!!
Member Since: Posts: Comments:
Quoting GeoffreyWPB:
White Christmas Probability Maps


Where were you when I asked for these the other night. Bordonaro had to get them!!!!!
Member Since: July 17, 2009 Posts: 63 Comments: 23739
We gonna book a room in Hattisburg,Miss..23-27th.

Southern Dixie,Elvis,Bing Crosby Style Christmas

And Jerry's kids,AKA , the "Dallas Cowboy's" are coming on over to the Superdome this Saturday here to play dem Saints..


The Dome will be full,Loud and cranky.

Should be fun,,come by canoe,..SUV,or wade if ya got too.

''..Im Dreaming,,of going 14 and 0'ohhhhhhhhhh".."

Member Since: Posts: Comments:
342. unf97
Quoting PensacolaDoug:
Ya gotta love the 18z gfs. White Christmas for darn near everyone if it should verify!


LOL. Boy that really would be something should that verify. But the GFS has been consistently for days forecasting the white stuff in the Deep South in the long range outlooks for Dec 24 -26.

We will see it comes to fruition.
Member Since: Posts: Comments:
New Orleans NWS Discussion
Member Since: Posts: Comments:
Is the front still expected to stall?
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting PensacolaDoug:
Ya gotta love the 18z gfs. White Christmas for darn near everyone if it should verify!


I promise, no white Christmas for me, unless I buy a REALLY big can of spray paint.

But I'm bored so I'll bite. How far into the southeast?
Member Since: Posts: Comments:
If you live below Laplace,on US 61 in Se.La.,
Airline is open but the 310 exit from I-10 west is closed due to high water still.,but 61 is open and modving between Kenner and St, Charles Parish..again,to Norco thru Laplace.

Funny seeing the Levee at the Parish Line open just wide nuff for 2 vehicles @ a time.

Lotta wet Cops too.

Folks Looked weary.

If this would have been snow,...I hate to think what it would be.

But the Sw Shore thru the Spillway to Kenner..,is full.

They gotta start raising US. 61 East and westbound between Norco and Kenner Like tomorrow.
Cuz if this rain did all this with no wind.

Dont buy now,cuz if the Gulf cranks out another low as forecasted..

Your gonna see this map a lot.

NEXRAD Radar
New Orleans, Storm Total Surface Rainfall Accumulation Range 124 NMI





Member Since: Posts: Comments:
I've noticed that for the past few months, the GFS just trucks along in the early days of the forecast and then around Day 7 or so just goes blam! and lights up the screen. I'd thought that would change as the season changed, but this hasn't happened so far. Does anyone have a view on why this is happening?
Member Since: Posts: Comments:
White Christmas Probability Maps
Member Since: Posts: Comments:
Quoting PensacolaDoug:
Ya gotta love the 18z gfs. White Christmas for darn near everyone if it should verify!

Shyea! I hope it does pan out but the odds are against us. That would be awesome tho wouldnt it?
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Cyclone Laurence intensifies off WA
Wednesday December 16, 2009 - 09:49 EDT

A tropical cyclone off the West Australian coast has become more powerful in the last couple of hours.

Tropical Cyclone Laurence is a category four system with winds of up to 260 kilometres per hour(161.5mph)

Residents of remote communities in the far north of Western Australia are on alert as the cyclone moves towards the coast.

It is currently about 300 kilometres north of Derby, near Kuri Bay, where residents have been urged to take shelter.

Cyclone Warning Centre duty forecaster Brad Santos says Laurence is small but very intense.

"Severe tropical Cyclone Laurence will be moving in a south-westerly direction and may impact the north-west Kimberley coast in the next day or two," he said.

People in areas near Kuri Bay have been warned to prepare for very destructive winds.

- ABC

TC Laurence is bordering on Cat 5 status... 142mph sustained winds and 161mph gusts.
Member Since: Posts: Comments:
Quoting hydrus:
It is(really) a sophisticated subject.Google this--The Mesoproterozioc Mid Continent rift System.
Did not find an answer. only verified that the ice flow and the rift were located in the samme areas but from different era
Member Since: Posts: Comments:
Know "Dreidel, Dreidel, Dreidel?

I know the South Park version, but, as usual, I would be banned into the next world for posting it on here...

;)
Member Since: Posts: Comments:


Holiday Greetings to everyone.
Member Since: Posts: Comments:
Ya gotta love the 18z gfs. White Christmas for darn near everyone if it should verify!
Member Since: Posts: Comments:
Quoting eyesontheweather:
what is a volcanic riff and which 2 were formed from the riff
It is(really) a sophisticated subject.Google this--The Mesoproterozioc Mid Continent rift System.
Member Since: Posts: Comments:
Quoting AwakeInMaryland:

Uh oh, I'm in (even bigger) trouble now, LOL!
I forget, where are you, Eyes? And what kind of stuff do you play? Know "Dreidel, Dreidel, Dreidel? For my grandkids? I like T-Dude's band's stuff...but he's crying "guitar in shop"! Um hmmmm...

I so off-topic... uh, how's the weather there?
I was in (practically) your backyard due to the Nor'easter in mid nov. and I play everything from classic rock to the blues to contemp christian, big band swing etc. Have been published as a muisician. The weather here is cold and getting colder with no end in sight until spring time.
Member Since: Posts: Comments:
Quoting hydrus:
Two were formed from volcanic rifts.
what is a volcanic riff and which 2 were formed from the riff
Member Since: Posts: Comments:
Quoting eyesontheweather:
Jeez, I wish I would have know that a month ago when I was in the area, I would have helped to lighten that burden. How bout if I pay the shipping today

Uh oh, I'm in (even bigger) trouble now, LOL!
I forget, where are you, Eyes? And what kind of stuff do you play? Know "Dreidel, Dreidel, Dreidel? For my grandkids? I like T-Dude's band's stuff...but he's crying "guitar in shop"! Um hmmmm...

I so off-topic... uh, how's the weather there?
Member Since: Posts: Comments:
Quoting Ossqss:
Humm, were not the Great Lakes made by Glaciers? :)


New Zealand was also made by glacier, and they still have glaciers on the South Island, Fox Glacier and the Franz Joseph. Been to both.
Member Since: Posts: Comments:
Quoting Ossqss:
Humm, were not the Great Lakes made by Glaciers? :)

Two were formed from volcanic rifts.
Member Since: Posts: Comments:
Quoting NRAamy:
well, you're still dashboard cow man to me.....

;)


Member Since: August 22, 2008 Posts: 12 Comments: 6010
Living about 25 miles north of South Bend, IN, I was quite frustrated when Texas got snow before we did. We've had about 8 inches of lake-effect snow since then but warm temps have left it yucky. I empathize with the pleas for snow coming from as far south as Florida. But then there is the cold! Thanks to Post #1396. toontown 8:16 PM GMT on December 14, 2009,
I found out about Edmonton's record low of -46*C and e-mailed a friend who is there for Christmas. This was her response:

Yep - they shut the airport down just after my plane got in on Saturday night because it was too cold for the ground crews to work. But Lois and I have gotten out for a good walk every morning in spite of the cold. Today should feel downright balmy -- we're going up to -23.

Need I add that she grew up north of Edmonton? Those Canadians are pretty tough, eh?
Member Since: Posts: Comments:
Humm, were not the Great Lakes made by Glaciers? :)



http://www.newscientist.com/article/dn12201
Member Since: Posts: Comments:
NWS Morristown, TN

.LONG TERM...(WEDNESDAY NIGHT THROUGH TUESDAY)...
MODELS SEEM TO BE COMING INTO BETTER AGREEMENT FOR THE END OF THE
WEEK...SHOWING A SOUTHERN STREAM SHORTWAVE TROUGH INDUCING MILLER A
CYCLONGENESIS OVER THE NORTHERN GULF. THE MERGING OF THE SOUTHERN
STREAM SHORTWAVE WITH THE NORTHERN STREAM
TROUGH SPREADS PRECIP
NORTHWARD INTO OUR AREA ON FRIDAY. THE 12Z GFS IS NOW IN BETTER
AGREEMENT WITH THE ECMWF REGARDING THIS PATTERN...SO CONFIDENCE IS
INCREASED.
WILL BRING SLIGHT CHANCE POPS INTO SOUTHERN AREAS ON
FRIDAY MORNING...AND BRING CHANCE POPS IN FRIDAY AFTERNOON THROUGH
SATURDAY. WITH THE TRACK OF THE SURFACE LOW BEING ACROSS BEING JUST
OFF THE GULF COAST AND ACROSS NORTHERN FL...WE WILL BE IN THE
FAVORED AREA FOR FRONTOGENESIS-INDUCED SNOWFALL.
GFS FORECAST
SOUNDINGS SUGGEST THAT PRECIP WILL BEGIN AS RAIN...THEN TRANSITION
TO SNOW FRIDAY NIGHT AS COLD ADVECTION INCREASES IN RESPONSE TO THE
STRENGTHENING LOW. AT THIS POINT...WILL USE WORDING OF RAIN OR SNOW
IN THE SOUTHERN AND CENTRAL VALLEY. BETTER MODEL AGREEMENT AND
RUN-TO-RUN CONSISTENCY WILL BE NEEDED TO MORE CLOSELY TARGET THE
LOCATION OF THE RAIN/SNOW LINE AND POTENTIAL SNOW AMOUNTS.

THE LOW WILL BE OFF THE CAROLINA COAST ON SUNDAY WITH THE UPPER
TROUGH AXIS OVER THE TN VALLEY. A LOW LEVEL NORTHWEST FLOW WITH COLD
MIDLEVEL TEMPS SUGGESTS A PERIOD OF UPSLOPE-INDUCED SNOW SATRUDAY
NIGHT AND SUNDAY. WITH THE FASTER TREND OF THE GFS AND ITS AGREEMENT
WITH THE ECMWF IN SHOWING WEAK RIDGING OVER THE AREA...WILL REMOVE
POPS FROM SUNDAY NIGHT AND MONDAY. HOWEVER IT WILL REMAIN COLD AS
CANADIAN HIGH PRESSURE SETTLES OVER THE AREA. THE GFS SUGGESTS
ANOTHER SHORTWAVE TROUGH MOVING THROUGH ON TUESDAY...BUT WILL GO DRY
FOR NOW.




Member Since: October 28, 2006 Posts: 57 Comments: 29714
319. xcool



18z snow .from 24 to 28.
Member Since: September 26, 2009 Posts: 2 Comments: 15603
Quoting AwakeInMaryland:

No worries 'bout WU mail; I wrote it on a whole beer and one-half...so it's prolly nonsense.

We have LOTS of guitars...which my hubby can't even really play...he just likes the craftsmanship. Please come pick one or two out, and I'll lie like a rug -- "oh yes, dear, there was a break-in while I was walking the dogs...they noticed there's nothing worth bubkas here except your gee-tars!"
Jeez, I wish I would have know that a month ago when I was in the area, I would have helped to lighten that burden. How bout if I pay the shipping today
Member Since: Posts: Comments:
Quoting Walshy:
Potential winter storm hitting here in north-west North Carolina. Could be the 1st snow east of the foothills as well into the major cities.

Models this far out still are not in agreement with what the low off the coast will do and how fast. Most of them are showing the low moving north-east off the Florida coast but then go everywhere.

NWS had cold and cloudy skies but now with the latest model runs they added 30% of snow here.


Yep. I'm keeping my fingers crossed for some snow!
Member Since: Posts: Comments:
Quoting Walshy:
Potential winter storm hitting here in north-west North Carolina. Could be the 1st snow east of the foothills as well into the major cities.

Models this far out still are not in agreement with what the low off the coast will do and how fast. Most of them are showing the low moving north-east off the Florida coast but then go everywhere.

NWS had cold and cloudy skies but now with the latest model runs they added 30% of snow here.


Yep. Keeping my fingers crossed for some snow!!
Member Since: Posts: Comments:
Potential winter storm hitting here in north-west North Carolina. Could be the 1st snow east of the foothills as well into the major cities.

Models this far out still are not in agreement with what the low off the coast will do and how fast. Most of them are showing the low moving north-east off the Florida coast but then go everywhere.

NWS had cold and cloudy skies but now with the latest model runs they added 30% of snow here.
Member Since: Posts: Comments:
Cooler weather a comin' :)

Local Text Forecast for
Lake Worth, FL (33461)

Dec 15 Tonight
Some clouds. Slight chance of a shower through the evening. Low 68F. Winds light and variable.
Dec 16 Tomorrow
Scattered showers in the morning, then variable clouds during the afternoon with a better chance of showers. High around 80F. Winds NE at 10 to 15 mph. Chance of rain 50%.
Dec 16 Tomorrow night
Cloudy with occasional rain showers. Low 69F. Winds NE at 10 to 15 mph. Chance of rain 50%.
Dec 17 Thursday
Cloudy with showers and thunderstorms.. Highs in the mid 70s and lows in the upper 60s.
Dec 18 Friday
Showers possible. Highs in the upper 70s and lows in the mid 60s.
Dec 19 Saturday
Mostly Cloudy. Highs in the mid 70s and lows in the mid 50s.
Dec 20 Sunday
Cloudy. Highs in the upper 60s and lows in the low 50s.
Dec 21 Monday
Clouds giving way to sun. Highs in the upper 60s and lows in the mid 50s.
Dec 22 Tuesday
Partly cloudy. Highs in the mid 70s and lows in the upper 50s.
Dec 23 Wednesday
Abundant sunshine. Highs in the mid 70s and lows in the low 60s.
Dec 24 Thursday
Abundant sunshine. Highs in the upper 70s and lows in the upper 60s.

MSN A Bit More Bullish
Member Since: Posts: Comments:
Quoting atmoaggie:

There is an official observation of something like 3 inches of rain for the whole month of December within ~60 miles of NOLA. (The Bootheville site mentioned from time to time)

*going outside to collect some rain to ship to hydrus, the dehydrated one*
.................................................................................................... .................Ship away, there are a lot of aquifers,trees and fauna that will surely put it use. Lawrence might be small in diameter, but that storm looks dangerous. I hope the people in its path are on there way inland. It is just skirting a huge portion of the coast, and probably doing heavy damage.
Member Since: Posts: Comments:

Viewing: 363 - 313

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.

Local Weather

Mostly Cloudy
39 °F
Mostly Cloudy