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 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.
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well, you're still dashboard cow man to me.....

;)
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Quoting hydrus:
Parts of Florida would like to have your rain. It is interesting areas relatively close to each other with such large differences in rainfall.

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*
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310. HadesGodWyvern (Mod)
BOM (Perth): 01U Laurence

2009DEC15 213000 6.3 921.9/ +2.7 /122.2 6.3 6.4 6.4 2.2T/6hr OFF OFF -58.01 -79.62 EYE -99 IR -15.30 -124.26 SPRL

T6.5 921 hPa
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From the Forecast Discussion NWS Indy:
IN THE EXTENDED...LONG RANGE MODELS AGREE IN PRINCIPLE ON LARGE
SCALE TROUGHING AFFECTING THE GREAT LAKES AND MIDWEST ONCE AGAIN
BEGINNING FRIDAY AND CONTINUING INTO NEXT WEEK. CONSISTENCY WITH
RESPECT TO TIMING/INTENSITY/EXACT LOCATION OF IMPULSES AND
ASSOCIATED SURFACE FEATURES/SENSIBLE WEATHER LEAVES MUCH TO BE
DESIRED. WE SHOULD SEE ONE OR MORE SHOTS OF SNOW THIS WEEKEND AND
PERHAPS EARLY NEXT WEEK.
..BUT IT IS A RELATIVE GUESSING GAME AS TO
EXACTLY WHEN AT THE MOMENT...THUS...WHEN LONGER RANGE GUIDANCE POPS
ARE AT THEIR PEAK...HAVE INSERTED A LOW CHANCE OF
SNOW...OTHERWISE...HAVE KEPT THE FORECAST DRY...AS SLIGHT
CHANCE/BELOW CLIMATOLOGY POPS IN THE EXTENDED DO NOT HAVE MUCH
SIGNIFICANCE. WHAT CAN BE SURMISED IS THAT TEMPERATURES WILL ONCE
AGAIN DIP WELL BELOW NORMAL.
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Quoting PcolaDan:


Alas, both he and the vehicle in the picture bit the dust. When we went to move him to the new car, his butt stayed behind on the dash - a ghastly sight for sure! He was also so faded he looked like an albino. RIP

btw - when we got him he was actually ---- Rudloph :O Yep it's really (was) a reindeer, but you can't tell from behind.


That's one of the saddest things I've ever heard...(insert recording of "TAPS", here...)

Geez, it's pitch dark outside! Human/Dog walk not going to be the best...
Member Since: August 19, 2008 Posts: 32 Comments: 1918
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!"


lol if only I could haha :P
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Quoting atmoaggie:

With only 8 inches to go? Could be.

Anyone have a drought they can share? Oh, you do? Excellent, thank you. Just haul it down to the UPS store, if you don't mind, and send it on down here.
Parts of Florida would like to have your rain. It is interesting areas relatively close to each other with such large differences in rainfall.
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Quoting NRAamy:
Quoting AwakeInMaryland:


VIDEOTAPE!? please, baby, please...



Awake, I didn't know you were a cougar!

;)


OH WHOOPS! I qualified for "Cougar" back in the 80's when I met my current husband! We didn't have the expression way back then...:)

To me, T-Dude would/could be "Baby Boy" or even "Grandbaby Boy"!
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting NRAamy:
dashboard cow man...too bad you can't dress the cow up for Christmas.....

:(


Alas, both he and the vehicle in the picture bit the dust. When we went to move him to the new car, his butt stayed behind on the dash - a ghastly sight for sure! He was also so faded he looked like an albino. RIP

btw - when we got him he was actually ---- Rudloph :O Yep it's really (was) a reindeer, but you can't tell from behind.
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Quoting Drakoen:


I think I have begun to especially with the scenarios that are more complex.


thats sweet, there is alot more involved from artic air to gulf of mexico lows, alot of room in between for stuff to happen. just keep us posted
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting tornadodude:


I cant play it right now, my guitar is currently being fixed

and the WU-mail? oh the one about the video, yeah I did, I just completely forgot to respond, sorry! :/

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!"
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting VAbeachhurricanes:


drak do you enjoy tracking these types of storms more?


I think I have begun to especially with the scenarios that are more complex.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
Quoting NRAamy:
Quoting AwakeInMaryland:


VIDEOTAPE!? please, baby, please...



Awake, I didn't know you were a cougar!

;)



HAHAHAHAHA
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting AwakeInMaryland:


VIDEOTAPE!? please, baby, please...



Awake, I didn't know you were a cougar!

;)
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297. HadesGodWyvern (Mod)
Tropical Cyclone Warning Center Perth
Tropical Cyclone Advice Number 38
SEVERE TROPICAL CYCLONE LAURENCE, CAT 4 (01U)
6:00 am AWST December 16 2009
==========================================

At 5:00 am WST, Severe Tropical Cyclone Laurence, Category 4 (944 hPa) located at 15.2S 124.3E has 10 minute sustained winds of 100 knots with gusts of 140 knots. The severe cyclone was estimated to be 40 kms northwest of Kuri Bay and 125 kms northeast of Cockatoo Island and moving southwest at 6 knots.

Severe Tropical Cyclone Laurence is a small but intense tropical cyclone having VERY DESTRUCTIVE WINDS with gusts to 260 kilometres per hour close to the cyclone centre. As Laurence tracks to the southwest near the Kimberley coast VERY DESTRUCTIVE winds may be experienced at Kuri Bay during Wednesday morning.

GALES with gusts to 100 kilometres per hour should extend further southwest along the coast, reaching Cockatoo and Koolan Islands during Wednesday and should the centre pass close by VERY DESTRUCTIVE winds are possible during the afternoon and evening. GALES may extend to Derby and Beagle Bay overnight Wednesday or on Thursday morning.

HEAVY RAIN is expected to continue over the north Kimberley region, extending into the western Kimberley during Wednesday and Thursday. Daily rainfall totals in excess of 100mm are possible near the coast with totals decreasing further inland.

---
Yikes he is turning into "George"
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Quoting AwakeInMaryland:


VIDEOTAPE!? please, baby, please...

Oh, did you ever get my WU-mail? Just wondering...I don't know how to check "sent" in WU mail. Is there even a way to check "sent" in WU mail??


I cant play it right now, my guitar is currently being fixed

and the WU-mail? oh the one about the video, yeah I did, I just completely forgot to respond, sorry! :/
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Quoting VAbeachhurricanes:


Its supposed to happen on sunday right? so might monday off.


From your post to Mother Nature's In-Box, Neighbor!
-------------------------------

T-Dude: Did I say "videotape"...omg, mental-pause -- how 20th C. of me!

Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting Drakoen:


Looks the event will be over the weekend. I would give around a 30-40%% chance of some snow as of right now.


drak do you enjoy tracking these types of storms more?
Member Since: September 6, 2007 Posts: 0 Comments: 6494
Quoting AwakeInMaryland:

Poo. Thanks for trying.


Its supposed to happen on sunday right? so might monday off.
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Quoting Drakoen:


Looks the event will be over the weekend. I would give around a 30-40%% chance of some snow as of right now.

Poo. Thanks for trying.
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting atmoaggie:
That looks like parts of 2 different storm tracks in the same plot, to me.

Yeah, AIM, they are the type would take in anyone, and with open arms.

Back later. Got work that refuses to do itself.

THANKS! for all of it...we've been bombarding you with questions!
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting StormChaser81:


Or one hell of a fast storm...


turned on the hyper-speed...
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Quoting tornadodude:


lol ill get right on it


VIDEOTAPE!? please, baby, please...

Oh, did you ever get my WU-mail? Just wondering...I don't know how to check "sent" in WU mail. Is there even a way to check "sent" in WU mail??
Member Since: August 19, 2008 Posts: 32 Comments: 1918
That looks like parts of 2 different storm tracks in the same plot, to me.

Yeah, AIM, they are the type would take in anyone, and with open arms.

Back later. Got work that refuses to do itself.
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dashboard cow man...too bad you can't dress the cow up for Christmas.....

:(
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Quoting HadesGodWyvern:


almost T6.0 on the dvorak scale

Based on the advisory, Laurence is a VERY tight storm, too. Hurricane force winds (on our scale) only 20nm from center, and TS winds a max of 50nm from the center.
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Quoting ricderr:
storm...that is a sever dog leg right...so i suggest you leave your driver in the bag and punch your three iron over the trees and cutting the corner


lol
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Quoting AwakeInMaryland:
We don't know enough about the rest of the orchestra to blame the violinist.

Play along on the bass/guitar then, T-Dude!
"Dreidel, dreidel, dreidel, I made it out of Clay; and when it's dry and ready, then Dreidel I will Play!"


lol ill get right on it
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Quoting StSimonsIslandGAGuy:
Think New Orleans will get 31" of rain in 31 days of December atmosaggie?

With only 8 inches to go? Could be.

Anyone have a drought they can share? Oh, you do? Excellent, thank you. Just haul it down to the UPS store, if you don't mind, and send it on down here.
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Quoting AwakeInMaryland:

Thanks a lot, Drak! Pls. schedule that during the week with BIG snow so hubby gets to stay home and walk dogs while I stay and watch fire in fireplace; TIA!


Looks the event will be over the weekend. I would give around a 30-40%% chance of some snow as of right now.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
storm...that is a sever dog leg right...so i suggest you leave your driver in the bag and punch your three iron over the trees and cutting the corner
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We don't know enough about the rest of the orchestra to blame the violinist.

Play along on the bass/guitar then, T-Dude!
"Dreidel, dreidel, dreidel, I made it out of Clay; and when it's dry and ready, then Dreidel I will Play!"
Member Since: August 19, 2008 Posts: 32 Comments: 1918
270. It looks like a lot more than missing data points. Hey everybody!
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Quoting tornadodude:


that is bizarre


Or one hell of a fast storm...
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Quoting Drakoen:


Yes I do for this weekend with the totals greatest in eastern Tennessee near the Appalachians where shortwave energy advecting eastward with moisture will allow for snow.
Thanks,I will check in for new info.
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Quoting whosonfirst:


Not implying anything, just pointing out that the paragraph you omitted puts the research into a much different light. Obviously something exceptional is going on on the Tibetan Plateau and any effort to extrapolate findings about climate there to a global scale are suspect, at best.

I was also wondering if this is the NASA study about aerosols and warming in the Arctic that you were talking about - Aerosols May Drive a Significant Portion of Arctic Warming? If so, I think you may have misrepresented the findings a bit. This is from the article:

"The researchers found that the mid and high latitudes are especially responsive to changes in the level of aerosols. Indeed, the model suggests aerosols likely account for 45 percent or more of the warming that has occurred in the Arctic during the last three decades. The results were published in the April issue of Nature Geoscience.

The thing is, when they say changes in the levels of aerosols, they talk about a decrease in sulfates from pollution controls as well as an increase in black carbon. So the soot component is only a fraction of that 45%.

If this isn't the study to which they were referring, mabye you could provide a link to the right one.


I'll find that other one soon, but, no, this is not the one I was referring to. That one has Hansen as a coauthor.

From your link:
"Sulfates, which come primarily from the burning of coal and oil, scatter incoming solar radiation and have a net cooling effect on climate. Over the past three decades, the United States and European countries have passed a series of laws that have reduced sulfate emissions by 50 percent. While improving air quality and aiding public health, the result has been less atmospheric cooling from sulfates.

At the same time, black carbon emissions have steadily risen, largely because of increasing emissions from Asia. Black carbon -- small, soot-like particles produced by industrial processes and the combustion of diesel and biofuels -- absorb incoming solar radiation and have a strong warming influence on the atmosphere.
"

Notice the sulfates "reduced", not removed. I don't think it a misrepresentation to postulate that more than 45% of warming could be due to soot. If the sulfates weren't there with their negative effect on atmospheric temps, it would be worse, obviously.

The quantitative effect of reducing sulfates 50% and increasing soot deposition on surface temps? Really has only been modeled at this point in time, as far as I know. But these NASA model results continue to show soot deposition to be substantial, relative to CO2 forcing.

We need so much more work done in the subjects of aerosol transport, deposition, atmospheric temp forcing, and ice melt.

Further reason to step away from the CO2 gorilla. We don't know enough about the rest of the orchestra to blame the violinist.
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Quoting StormChaser81:


Is this a screw up or is it missing data points?


that is bizarre
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Quoting Drakoen:
There is still a lot of thing to work out with this upcoming storm so stay tuned for the updates.

Thanks a lot, Drak! Pls. schedule that during the week with BIG snow so hubby gets to stay home and walk dogs while I stay and watch fire in fireplace; TIA!
Member Since: August 19, 2008 Posts: 32 Comments: 1918


Is this a screw up or is it missing data points?
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There is still a lot of thing to work out with this upcoming storm so stay tuned for the updates.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
Quoting hydrus:
Drakoen, Do you see any snow for the Tennessee Valley? Some models show a stormy period from the 24th until the end of the month.


Yes I do for this weekend with the totals greatest in eastern Tennessee near the Appalachians where shortwave energy advecting eastward with moisture will allow for snow.
Member Since: October 28, 2006 Posts: 57 Comments: 30490
Quoting atmoaggie:

Well somebody is having fun...

No, I have only a BS. Some grad school coursework, but no masters.

The family? Ehh, the full range from pipe-fitters to MDs to PhDs in Liberal Arts.

Those statistics are odd. There has to be at least one dentist in that town...not to mention other medical professionals.

You're right...unless it's "sort of" like our 'burbs...meaning the towns change names one block away.
NO fun? Is it me, or work? Uh, you don't have to answer that!

But you avoided the other question!
The question is, would I be a problem for THEM?
Member Since: August 19, 2008 Posts: 32 Comments: 1918
Quoting Drakoen:
Teleconnections still show a positive PNA, and strongly negative AO, and a negative NAO.


So mind your p's and q's. :)
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Quoting VAbeachhurricanes:


what about VA drak, we want some snow too! :)


If the current models were to pan out Virginia would see snow especially looking at the ECMWF and GGEM with the deformation axis stretching out towards Lake Erie.
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263. HadesGodWyvern (Mod)


almost T6.0 on the dvorak scale
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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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