future greenland melt

[Old Rocks]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

 

[polarbear]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So why don`t you use your fridge and make a few ice cubes and bring`em to Canada or Greenland to make up for it, + the next time you freeze your ass off you can shove a few up your ass and enjoy the "back radiation"..according to your "science" it should work

 

[RollingThunder]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So why don`t you use bla-bla-bla-retarded-drivel.

Why don't you grow a brain?

Oh right, you're too low on the evolutionary ladder to do that yet.

Maybe someday when you amount to more than a pimple on a toad's butthole, you'll manage to scrape together a few brain cells and say something coherent but until then, your 'contributions' to this forum are worth less than a cup of moldy catpoop.

 

[skookerasbil]

 

[Old Rocks]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So why don`t you use your fridge and make a few ice cubes and bring`em to Canada or Greenland to make up for it, + the next time you freeze your ass off you can shove a few up your ass and enjoy the "back radiation"..according to your "science" it should work

Bi-Polar

 

[Douger]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So why don`t you use your fridge and make a few ice cubes and bring`em to Canada or Greenland to make up for it, + the next time you freeze your ass off you can shove a few up your ass and enjoy the "back radiation"..according to your "science" it should work

Bi-Polar

You have to be. Both are disappearing making it a requirement to travel from one to the other on a seasonal basis !

 

[waltky]

Global warming caused by the buildup of greenhouse gases in the atmosphere melting Greenland ice...

Some Of The Oldest Ice In The Arctic Is Now Breaking Apart
August 23, 2018 - A huge pack of floating ice along the northern Greenland coastline is breaking up and drifting apart into the Arctic Ocean — another consequence, scientists say, of global warming caused by the buildup of greenhouse gases in the atmosphere.

"We've never seen anything this large in terms of an opening north of Greenland," says polar scientist Ted Scambos of the National Snow and Ice Data Center at the National Oceanic and Atmospheric Administration. This sea ice is some of the oldest and thickest in the Arctic. Wind and currents normally shove lots of ice up against the northern coast of Greenland, where it stacks up and clings for years. "It's like a crowd entering a stadium," Scambos says. "It's sort of pushed by the ice behind it until it's packed really tight, and that's made it thick and durable." Think of those long-lasting mounds of ice left on city streets by snowplows — but up to 30 feet thick.

Sea ice is seen from NASA's Operation IceBridge research aircraft off the northwest coast of Greenland​

Global warming, however, has finally begun to break up this ice, Scambos says. The Arctic is warming faster than any other part of the planet; last February saw remarkably warm winter temperatures there. The normally year-round frozen ice "kind of rattles around in the arctic now," he says. "And [in] this area north of Greenland, what we're seeing is that the ice is so thin and sort of loosely packed that a few days of strong winds in an unusual direction can push the ice away from the coast that it always collided with in its drift pattern."

Polar scientists have watched the duration and extent of Arctic Ocean ice decline for many years as a result of warming. But the loss of the Greenland section shows that warming is also changing how ice moves. And while the Greenland ice breakup may be out of sight, for polar scientists, it's not out of mind. It's another shift in the Arctic environment caused by warming. And scientists point out that the Arctic environment — its ocean currents, ice floes, and wind patterns — affects the jet stream, which in turn influences the weather people get across the Northern Hemisphere.

Some Of The Oldest Ice In The Arctic Is Now Breaking Apart

 

[skookerasbil]

Lol....one of my old Photobucket Classics!!

Nobody cares about Greenland.

 

[JLW]

There will be no action taken on climate change because too many dolts with Dunning-Kruger think they know all there is to know. Unfortunately, my kids live on the same planet with these fucking morons so they will deal with the consequences. These fucking morons will long be dead and buried so they will not face the results of their idiocy.

 

[HereWeGoAgain]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So any idea why it's called Greenland?

 

[skookerasbil]

There will be no action taken on climate change because too many dolts with Dunning-Kruger think they know all there is to know. Unfortunately, my kids live on the same planet with these fucking morons so they will deal with the consequences. These fucking morons will long be dead and buried so they will not face the results of their idiocy.

That's right s0n....tough shit on you! You and all the other climate change k00ks enjoy the bumpy cucumber.

 

[Toddsterpatriot]

There will be no action taken on climate change because too many dolts with Dunning-Kruger think they know all there is to know. Unfortunately, my kids live on the same planet with these fucking morons so they will deal with the consequences. These fucking morons will long be dead and buried so they will not face the results of their idiocy.

It's too bad we don't have a large-scale source of reliable, CO2 free energy cough-nuclear-cough eh?

 

[CrusaderFrank]

The ice has been melting for the past 14,000 years. Why is this news?

 

[TNHarley]

There will be no action taken on climate change because too many dolts with Dunning-Kruger think they know all there is to know. Unfortunately, my kids live on the same planet with these fucking morons so they will deal with the consequences. These fucking morons will long be dead and buried so they will not face the results of their idiocy.

Im sorry but it seems terribly ignorant to think you can change earths natural evolution.

 

[Billy_Bob]

Global warming caused by the buildup of greenhouse gases in the atmosphere melting Greenland ice...

Some Of The Oldest Ice In The Arctic Is Now Breaking Apart
August 23, 2018 - A huge pack of floating ice along the northern Greenland coastline is breaking up and drifting apart into the Arctic Ocean — another consequence, scientists say, of global warming caused by the buildup of greenhouse gases in the atmosphere.

"We've never seen anything this large in terms of an opening north of Greenland," says polar scientist Ted Scambos of the National Snow and Ice Data Center at the National Oceanic and Atmospheric Administration. This sea ice is some of the oldest and thickest in the Arctic. Wind and currents normally shove lots of ice up against the northern coast of Greenland, where it stacks up and clings for years. "It's like a crowd entering a stadium," Scambos says. "It's sort of pushed by the ice behind it until it's packed really tight, and that's made it thick and durable." Think of those long-lasting mounds of ice left on city streets by snowplows — but up to 30 feet thick.

Sea ice is seen from NASA's Operation IceBridge research aircraft off the northwest coast of Greenland​

Global warming, however, has finally begun to break up this ice, Scambos says. The Arctic is warming faster than any other part of the planet; last February saw remarkably warm winter temperatures there. The normally year-round frozen ice "kind of rattles around in the arctic now," he says. "And [in] this area north of Greenland, what we're seeing is that the ice is so thin and sort of loosely packed that a few days of strong winds in an unusual direction can push the ice away from the coast that it always collided with in its drift pattern."

Polar scientists have watched the duration and extent of Arctic Ocean ice decline for many years as a result of warming. But the loss of the Greenland section shows that warming is also changing how ice moves. And while the Greenland ice breakup may be out of sight, for polar scientists, it's not out of mind. It's another shift in the Arctic environment caused by warming. And scientists point out that the Arctic environment — its ocean currents, ice floes, and wind patterns — affects the jet stream, which in turn influences the weather people get across the Northern Hemisphere.

Some Of The Oldest Ice In The Arctic Is Now Breaking Apart

There is massive new ice buildup at the top forcing movement down..Calving is not a new development but alarmist are sure going overboard for natural variation...

 

[Yarddog]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So any idea why it's called Greenland?

It actually was false advertising .... seriously

 

[Yarddog]

Has anyone asked the Innuits in Greenland? maybe they are happy about this. now they can start up some farms make some money and dont have to freeze their asses off.

 

[HereWeGoAgain]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So any idea why it's called Greenland?

It actually was false advertising .... seriously

Ancient Greenland was much warmer than previously thought: New knowledge helps researchers understand how Greenland's ice sheet responds to warming

 

[Old Rocks]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So any idea why it's called Greenland?

Why yes, marketing ploy by Eric the Red. So why did you not know that?

 

[Old Rocks]

AGW Observer

Ice surface melt area might cover whole Greenland ice sheet within decade

Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers – Box et al. (2012) [FULL TEXT]

Abstract: “Greenland ice sheet mass loss has accelerated in the past decade 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. Using satellite-derived surface albedo with calibrated regional climate modeled surface air temperature and surface downward solar irradiance, we determine the spatial dependence and quantitative impact of the ice sheet albedo feedback over 12 summer periods beginning in 2000. We find that, while albedo feedback defined by the change in net solar shortwave flux and temperature over time is positive over 97% of the ice sheet, when defined using paired annual anomalies, a second-order negative feedback is evident over 63% of the accumulation area. This negative feedback damps the accumulation area response to warming due to a positive correlation between snowfall and surface air temperature anomalies. Positive anomaly-gauged feedback concentrated in the ablation area accounts for more than half of the overall increase in melting when satellite-derived melt duration is used to define the timing when net shortwave flux is sunk into melting. Abnormally strong anticyclonic circulation, associated with a persistent summer North Atlantic Oscillation extreme since 2007, enabled three 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 approached positive values during this period. Thus, it is reasonable to expect 100% melt area over the ice sheet within another similar decade of warming.”

Citation: Box, J. E., Fettweis, X., Stroeve, J. C., Tedesco, M., Hall, D. K., and Steffen, K.: Greenland ice sheet albedo feedback: thermodynamics and atmospheric drivers, The Cryosphere, 6, 821-839, doi:10.5194/tc-6-821-2012, 2012.

So any idea why it's called Greenland?

It actually was false advertising .... seriously

Ancient Greenland was much warmer than previously thought: New knowledge helps researchers understand how Greenland's ice sheet responds to warming

This information could help researchers better gauge Greenland's sensitivity to warming, by testing and improving models of climate and ice sheet behavior. Those models could then improve predictions of how Greenland's ice sheet, which covers 80 percent of the Arctic country and holds enough ice to equal 20 feet of global sea level, might respond to human-made global warming.

"Northwest Greenland might feel really remote, but what happens to that ice sheet is going to matter to everyone in New York City, Miami and every coastal city around the world," said Yarrow Axford, the study's senior author and an associate professor of Earth and planetary sciences at Northwestern. "One of the big uncertainties in climate science remains how fast the Earth changes when it gets warmer. Geology gives us an opportunity to see what happened when the Earth was warmer than today."

Published June 4 in the Proceedings of the National Academy of Sciences, the study included contributions from collaborators at Dartmouth College.

Ancient Greenland was much warmer than previously thought: New knowledge helps researchers understand how Greenland's ice sheet responds to warming