2014 Greenland melt season discussion thread

[tacoman25]

Why use a 20 year average when there is a 30 year available?

 

 

Because that was the first source I clicked on when searching.

 

Either way, it shows the same thing: abrupt end to the melt season.

[The_Global_Warmer]

From the article:

 

"She and seven other researchers used a new model to simulate the effect of the changing climate on the Petermann, Kangerdlugssuaq, Helheim and Jakobshavn Isbræ glaciers out to the year 2200. These four glaciers transport ice from more than 20 percent of the Greenland ice sheet.

 

“A crucial fact is that these two scenarios are equally probable. So the extreme variation could be more correct than the more moderate one. This is rather frightening when we find that the warmer scenario results in a 50 percent greater loss of ice from the Greenland glaciers by the end of the 22nd century,” says Nick.

 

The total loss of ice from the four glaciers alone in the moderate scenario will raise sea levels by 8.5 to 13 millimetres by the year 2100. In the more extreme scenario, the rise due to the melting of the glaciers will be between 11 to 17.5 millimetres."

 

That melt rate accounts for only 20 percent of the total Greenland melt rate, and as noted by the scientists who did this study, the worse case scenario is just as likely as the best case scenario.

 

 

Good point.

[The_Global_Warmer]

Because that was the first source I clicked on when searching.

 

Either way, it shows the same thing: abrupt end to the melt season.

 

 

Still only goes slightly below normal for a day or two.

 

:lmao:

[tacoman25]

Still only goes slightly below normal for a day or two.

 

:lmao:

 

True, though if you look at the 20 year average graph (more reflective of the +AMO phase we are still in), we were below normal a fair amount this summer. 

[The_Global_Warmer]

Almost over now.

 

A little hitch in albedo plummeting because the Southern 1/3rd of GIS still has very low albedo for this time of year.

 

 

 

 

[The_Global_Warmer]

Pretty impressive.  GIS is going thru some major changes.

 

It is certainly not good that so much of Northern GIS set new August record lows in albedo.  As well as so high up in elevation. 

 

We keep inching closer and closer to substantial melt spreading into the 1500-2200M range over GIS in the Summers. When the break thru happens we will see the area of melt ponds double or triple in area from where it is now. 

 

Which will have huge ramifications for surface melt as well as glacial discharge.

 

 

 

 

 

 

[LithiaWx]

2014 was a yawner of a melt season for greenland. It experienced a very benign melt compared to higher melt years like 2012. When we start talking about albedo that's a pretty good sign actual melt was pretty pathetic.

[The_Global_Warmer]

Whats up with the childish trolling and peddling of ignorance?  It's very obnoxious and disrespectful.

 

Wattsupwiththat?

 

There is a team of scientists with PHDs spending their summers on GIS soley to observe and document the albedo changes for a better understanding of what is happening because of how powerful albedo change on an Island or ice is.

 

 

 

 

https://twitter.com/climate_ice

 

http://darksnow.org/

 

 

 

 

Greenland ice sheet albedo feedback: mass balance implications August 7th, 2012

Here’s a preview of my American Geophysical Union presentation abstract…

Greenland ice sheet albedo feedback: mass balance implications

Jason E Box1, Marco Tedesco2, Xavier Fettweis3, Dorothy K Hall4, Konrad Steffen5, Julienne Christine Stroeve6

1. Byrd Polar Rsch Ctr Scott Hall, The Ohio State University, Columbus, OH, United States.
2. The City University of New York, New York City, NY, United States.
3. Department of Geography, University of Liege, Liege, Belgium.
4. NASA Goddard Space Flight Center, Greenbelt, MD, United States.
5. Swiss Federal Institute for Forest, Snow and Landscape Research ( WSL) , Birmensdorf, Switzerland.
6. National Snow and Ice Data Center, Boulder, CO, United States.

 Greenland ice sheet mass loss has accelerated responding to combined glacier discharge and surface melt water runoff increases. During summer, absorbed solar energy, modulated at the surface primarily by albedo, is the dominant factor governing surface melt variability in the ablation area. NASA MODIS data spanning 13 summers (2000 – 2012), indicate that mid-summer (July) ice sheet albedo declined by 0.064 from a value of 0.752 in the early 2000s. The ice sheet accordingly absorbed 100 EJ more solar energy for the month of July in 2012 than in the early 2000s. This additional energy flux during summer doubled melt rates in the ice sheet ablation area during the observation period.

Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme 2007-2012, enabled 3 amplifying mechanisms to maximize the albedo feedback: 1) increased warm (south) air advection along the western ice sheet increased surface sensible heating that in turn enhanced snow grain metamorphic rates, further reducing albedo; 2) increased surface downward shortwave flux, leading to more surface heating and further albedo reduction; and 3) reduced snowfall rates sustained low albedo, maximizing surface solar heating, progressively lowering albedo over multiple years. The summer net infrared and solar radiation for the high elevation accumulation area reached positive values during this period, contributing to an abrupt melt area increase in 2012.

A number of factors make it reasonable to expect more melt episodes covering 100% of the ice sheet area in coming years: 1) the past 13 y of increasing surface air temperatures have eroded snowpack ‘cold content’, preconditioning the ice sheet for earlier melt onset. Less heat is required to bring the surface to melting; 2) Greenland temperatures, have lagged the N Hemisphere average in the 2000s, need to increase further for Greenland to be in phase with the N Hemisphere average. 3) Arctic amplification of enhanced greenhouse warming is driven by albedo feedback over sea ice, terrestrial environments, and through autumn-winter heat release from open water areas. Likely melt area increases is despite a second order negative feedback operating in the accumulation area identified statistically from more summer snowfall (brightening effect) in anomalously warm summers. Without this negative feedback, the accumulation area complete surface melting may have happened sooner than in 2012.

While it has been shown that the ice sheet dynamics can adjust rapidly to ice flow perturbations, a negative feedback responsivity, the mass imbalance of the ice sheet in the coming decades is likely to be increasingly negative because of the positive feedback from surface albedo with air temperature. Surface melting may therefore increasingly dominate ice sheet mass loss, as glaciers retreat from a marine termini and the area of low albedo expands over the gradually sloping ice sheet. The albedo feedback ensures an increasing solar energy absorption. What could shut the positive feedback down would be a combination of an anomalously cold winter and anomalously thick snowpack. This scenario is possible given the cooling effect of a major N Hemisphere volcanic eruption or some other event to reduce surface heating.

 

 

 

 

Sky selfie

Our colleague Jason Box of the Geological Survey of Denmark and Greenland (GEUS), and graduate student Johnny Ryan of Aberystwyth University spent much of the summer on the western ice sheet at Camp Dark Snow, near Kangerlugssuaq on the Arctic Circle (67 degrees north latitude at 1,010 meters above sea level). The team was investigating the Greenland surface albedo, climate, and surface melting, and how these evolve during summer. As part of the research, they have been using drones (Unmanned Aerial Vehicles, or UAVs) to photograph the surface from low altitude to examine the development of surface structures associated with melting. Strips of images and albedo measurements from the UAV are compared with simultaneous satellite images from the NASA MODIS sensor as an intermediate state to relate ground albedo measurements with that of the entire ice sheet. UAV photos reveal a surface riven with fractures, and drained by ephemeral rivers of melt water. The mid-summer melt surface in this area is pocked with 0.5 to 1 meter-wide (1.5 to 3 feet-wide) potholes with black grit and dust collected at the bottom. This black material is called cryoconite, and is comprised of dust and soot deposited on the surface, and melted out from the older ice exposed by melting. The dark patches are often glued together by tiny microbes.

 

 

 

Sky selfie

Posted on August 22, 2014by Jason Box

Reply

from part of NSIDC’s Greenland-today 20 August, 2014 post…

Sky selfie

Our colleague Jason Box of the Geological Survey of Denmark and Greenland (GEUS), and graduate student Johnny Ryan of Aberystwyth University spent much of the summer on the western ice sheet at Camp Dark Snow, near Kangerlugssuaq on the Arctic Circle (67 degrees north latitude at 1,010 meters above sea level). The team was investigating the Greenland surface albedo, climate, and surface melting, and how these evolve during summer. As part of the research, they have been using drones (Unmanned Aerial Vehicles, or UAVs) to photograph the surface from low altitude to examine the development of surface structures associated with melting. Strips of images and albedo measurements from the UAV are compared with simultaneous satellite images from the NASA MODIS sensor as an intermediate state to relate ground albedo measurements with that of the entire ice sheet. UAV photos reveal a surface riven with fractures, and drained by ephemeral rivers of melt water. The mid-summer melt surface in this area is pocked with 0.5 to 1 meter-wide (1.5 to 3 feet-wide) potholes with black grit and dust collected at the bottom. This black material is called cryoconite, and is comprised of dust and soot deposited on the surface, and melted out from the older ice exposed by melting. The dark patches are often glued together by tiny microbes.

 

Images of the Greenland Ice Sheet near Kangerlugssuaq in west-central Greenland taken by a drone (UAV) used to evaluate the evolving albedo of the ice sheet surface during the summer melt season. At top left, Prof. Jason Box and Johnny Ryan, a Ph.D. student at Aberystwyth University, hold the drone they used. Top left, the drone takes a picture of the surface (and the operator, J. Ryan) on August 9, 2014 from low altitude, showing numerous cryoconite holes filled with black dust, grit, and soot that had accumulated in the winter snowpack, and melted out of the older ice below. Bottom, a higher-altitude image of the same area reveals sinuous melt streams and linear fractures, as well as small speckles of cryoconite holes on the ice sheet. Tents from the camp are also visible as colorful dots against the ice surface. 

ps. Professors Alun Hubbard and Niel Snooke at Aberystwyth University deserve a lot of credit for the UAV development.

 

 

 

[nflwxman]

2014 was a yawner of a melt season for greenland. It experienced a very benign melt compared to higher melt years like 2012. When we start talking about albedo that's a pretty good sign actual melt was pretty pathetic.

I hate to do this, but this is an awfully misleading post. I assume you don't follow Greenland very much based on your lack of understanding of albedo and rapid dynamical ice flow from the sheet. Melt extent was almost 2 sigma above average, and that is only one minor part of the puzzle that you are focusing on.

Please stop trolling, if that is your goal. If not, get educated on the topic.

[AvantHiatus]

2014 was a yawner of a melt season for greenland. It experienced a very benign melt compared to higher melt years like 2012. When we start talking about albedo that's a pretty good sign actual melt was pretty pathetic.

Flat-out lie. You are clearly unable to read the albedo map, other areas outside the blue-shade also experienced melt but not at record levels. You can still have melt over a wider area with less severe intensity and come out with greater overall melt than 2012.

[PhillipS]

It appears to me that the 2014 GIS mass balance will be about midway between the heavy loss of 2012 adn fthe mild loss of 2013.  Here are the current plots from Polarportal.dk [link]:

 

 

Important Note:  As others have pointed out in previous posts, the red line is mislabeled, it should be labeled 2013.

 

And the accumulated GIS mass balance through early 2014:

 

 

As you can see, the GIS has lost about 3200 Gtons of ice over 10 years.  2014 will add another 350 or so Gtons to the total loss.  I find that sobering, especially given the observed albedo changes and glacial accelerations.

[PhillipS]

Something odd - there has been a recent uptick in GIS melting.

 

But what seem odd to me is where the melting is occurring.

 

 

Why is there melting in NE Greenland this time of year?  Hasn't the Sun set for the winter?  Can anybody shed some light on this?  (pun intended)

[bluewave]

Something odd - there has been a recent uptick in GIS melting.

 

 

But what seem odd to me is where the melting is occurring.

 

Why is there melting in NE Greenland this time of year?  Hasn't the Sun set for the winter?  Can anybody shed some light on this?  (pun intended)

 

It due to the very strong blocking episode that recently developed. The Arctic Oscillation dropped to its lowest

levels since March into early April 2013.

[PhillipS]

It due to the very strong blocking episode that recently developed. The Arctic Oscillation dropped to its lowest

levels since March into early April 2013.

 

Thanks, that makes sense.

[bluewave]

Thanks, that makes sense.

 

Yeah, Greenland is fortunate that we had a lull in the strong blocking for the last 2 summers.

The blocking pattern this summer was weaker than 2007-2012, but warmer than the strong

polar vortex near Greenland in 2013.

 

 

 

[LithiaWx]

I hate to do this, but this is an awfully misleading post. I assume you don't follow Greenland very much based on your lack of understanding of albedo and rapid dynamical ice flow from the sheet. Melt extent was almost 2 sigma above average, and that is only one minor part of the puzzle that you are focusing on.

Please stop trolling, if that is your goal. If not, get educated on the topic.

  

Flat-out lie. You are clearly unable to read the albedo map, other areas outside the blue-shade also experienced melt but not at record levels. You can still have melt over a wider area with less severe intensity and come out with greater overall melt than 2012.

My opinion that 2014's melt doesn't hold a candle to 2012 is opinion. I don't view Greenland ice sheet melt as a problem for humanity. 2012 was in a world of its own. If you read through this thread you would think 2014 was as bad or worse and it isn't. No lies, no distortion. I'm not alarmed about albedo in Greenland. If you compare 2012 and 2014 on any metric other than albedo you should see a stark contrast.

[nflwxman]

  

My opinion that 2014's melt doesn't hold a candle to 2012 is opinion. I don't view Greenland ice sheet melt as a problem for humanity. 2012 was in a world of its own. If you read through this thread you would think 2014 was as bad or worse and it isn't. No lies, no distortion. I'm not alarmed about albedo in Greenland. If you compare 2012 and 2014 on any metric other than albedo you should see a stark contrast.

 

Perhaps, but how is comparing every year to 2012 useful?  Trends are the important statistic here, not how one year compares to another in a some arbitrary snapshot in time.

 

I would think, based on the trends, that 2012 will start becoming the normal in 10-15 years.  

[icebreaker5221]

So tonight, a friend of a friend made the statement that Greenland has overall gained mass over the last 20 and 30 years.  I'm certain this is false, but does anyone have a real-time link I can share that goes back that far?  Even if we were to ignore global climate change altogether, other factors such as the AMO, NAO (and the bipolar seesaw if it does indeed exist) would argue for lower ice mass over Greenland now than in the 1980s for sure. 

 

He later referred to the following link, which doesn't give any references and appears to be complete baloney:

http://www.longrangeweather.com/ArticleArchives/GreenlandIceSheet.htm

 

As an aside, who is this Cliff Harris - self-proclaimed top 10 climatologists in the world?

http://www.longrangeweather.com/About-Us.htm

[The_Global_Warmer]

We won't know how 2014 has done until December.

 

Albedo changes are everything on GIS and the future of GIS.

 

Albedo changes over GISS can changes the amount of surface melt 5, 10, maybe 20 times over versus what we have seen recently.

 

So far only about 10% of GIS has seen dark particles collect and become embedded in the top layers of the ice sheet.

 

We can only hope the spreading of this phenomenon over the rest of the Island of ice is very slow.

[PhillipS]

So tonight, a friend of a friend made the statement that Greenland has overall gained mass over the last 20 and 30 years.  I'm certain this is false, but does anyone have a real-time link I can share that goes back that far?  Even if we were to ignore global climate change altogether, other factors such as the AMO, NAO (and the bipolar seesaw if it does indeed exist) would argue for lower ice mass over Greenland now than in the 1980s for sure. 

 

He later referred to the following link, which doesn't give any references and appears to be complete baloney:

http://www.longrangeweather.com/ArticleArchives/GreenlandIceSheet.htm

 

As an aside, who is this Cliff Harris - self-proclaimed top 10 climatologists in the world?

http://www.longrangeweather.com/About-Us.htm

 

The GIS  was gaining mass for much of the 20th century but that tapered off and switched to a net mass loss regime which is the situation today.  Here is the chart you've probably seen based on data from the GRACE satellite:

 

 

As you can see, the GIS has lost a total of around 3200 Gtons of mass in about ten years.

 

What you have to keep in mind when reading many posts and articles on the GIS mass balance is the distinction between the surface mass balance and the net mass balance.  Many authors conflate the two, whether through ignorance or dishonesty you'll have to decide for yourself.   That's the case for the post you linked to.  The surface mass balance includes only precipitation and surface melting.  Many areas in the interior of Greenland can add several meters of snow annually.  The story of the 'Lost Squadron' of P-38s buried under 200 feet or so of snow and firn is true.  200 feet accumulation in about 50 years (when Glacier Girl was recovered) is a lot of snow.  So the surface mass balance in the past was usually positive and even now is fairly neutral.  Here is the surface plot:

 

 

As you can see 2014 had a below average surface accumulation.

 

The overall GIS net mass balance includes the processes of glacial calving and meltwater lost through moulins.  These have become the dominant processes and outlet glaciers have increased their speed and the albedo changes have increased melting, particularly at lower altitudes.  A single single calving event can involve tens of Gtons of mass loss.  A fascinating, though sobering, video to watch is the Chasing Ice clip on the largest calving event ever recorded.  It's on youtube.

[forkyfork]

[Jonger]

Gravity.

[PhillipS]

Polarportal.dk has posted their update for the 2014 GIS melt season.  Here's the plot:

 

 

As we can see, 2014 had a lower net mass loss than 2012, but it was higher than 2013.  Here's the long -term GIS plot:

 

It only shows mass balance through the Spring but since 2014 is close to 2012 then the cumulative GIS mass loss since 2003 will approach 3,500 gigatons (km3).  That's a lot of water.

[LithiaWx]

Melt season is over. The graph above is labeled wrong. It's been pointed out a half dozen times in the thread but for some reason continues to be posted without notice that the years are not labeled correctly.

[PhillipS]

Melt season is over. The graph above is labeled wrong. It's been pointed out a half dozen times in the thread but for some reason continues to be posted without notice that the years are not labeled correctly.

 

The chart has been corrected from earlier versions and is accurate.  Surface melt season is essentially over, but the GIS mass loss through glacial calving continues year round.  Here's the current chart from NSIDC where you can see that surface melt was still ongoing in late Oct.

 

[LithiaWx]

The chart has been corrected from earlier versions and is accurate.  Surface melt season is essentially over, but the GIS mass loss through glacial calving continues year round.  Here's the current chart from NSIDC where you can see that surface melt was still ongoing in late Oct.

 

2012 and 2014 were not that close. The graph is still wrong. It's been pointed out over and over again as a mistake.

[LithiaWx]

Pretty sure the sub topic heading isn't still appropriate and will only confuse those coming here to learn much like the graph that is labeled wrong. Things are bad enough in Greenland without having to make them seem worse than they really are through deception.

[AvantHiatus]

Pretty sure the sub topic heading isn't still appropriate and will only confuse those coming here to learn much like the graph that is labeled wrong. Things are bad enough in Greenland without having to make them seem worse than they really are through deception.

Nastier than 2013, which I would assume moves it 3/4 of the way towards 2012. I don't think it's that far off and it's bad and unethical to call something deceptive without evidence.

[LithiaWx]

Nastier than 2013, which I would assume moves it 3/4 of the way towards 2012. I don't think it's that far off and it's bad and unethical to call something deceptive without evidence.

The evidence has been posted more than once in this thread.

[PhillipS]

Here is the incorrect plot that I posted earlier:

 

As several people pointed out, the red line labeled 2012 should read 2013, which was a very mild year for GIS mass loss.

 

Here is the current and correct plotL

 

And now notice that the red line labeled 2012 is correct (2012 was a record year for GIS mass loss).  As anyone can see, 2014 nearly tied 2012 for net mass loss.

 

Marietta, continuing to deny the data does nothing for your credibility.