Greenland's albedo is changing due to warming temperatures

[LocoAko]

Sorry if this is old news. We know ice is melting near the poles, but I was interested to learn that the albedo of Greenland is changing (significantly, too!) due to changing snowflake geometries within the snowcover of Greenland.

http://www.ess.uci.e...s/rignot2012010

The ice sheet covering Greenland is growing darker in response to global warming, new satellite data show, an effect that reaches into the interior and has altered virtually the entire surface of the island.

The darkening also feeds on itself: The less reflective the ice sheet becomes, the more warmth it absorbs, and the more melting accelerates.

The ice sheet now reflects as much as 20 percent less sunlight during summer than it did from 2000 to 2006.

“The signal is not just localized on the coast,” said Eric Rignot, a research scientist at

UC Irvine and NASA’s Jet Propulsion Laboratory who specializes in polar ice but was not involved in the study.

“You can see the impact of warming over the whole ice sheet,” Rignot said. “That was a surprising result to me.”

The finding appears as part of the 2011

Arctic Report Card from the National Oceanic and Atmospheric Administration.

The study relies on data from NASA satellites and was led by researcher Jason Box of

Ohio State University.

Along the edges of Greenland, bare ground is exposed and pools of water form. Meanwhile, snow melts, exposing the less reflective ice beneath, which can be further darkened by windblown dust.

But the darkening has another cause in Greenland’s interior. There, the ice sheet rises in a dome nearly two miles above sea level, and melting is not a factor.

“So the snow absorbs more energy from the sun, and gets warmer,” said Rignot, whose own research has shown that ice-sheet melting

appears to be accelerating at both poles.Instead, ice crystals change shape as temperatures increase. They lose their sharp, reflective edges and begin to clump; both changes result in lower reflectiveness.

[Vergent]

This is not good.

[Kelathos]

Before you speak of the changes 'due to warming temperatures', you may wish to look at 80 Years Of Temperature Decline In Greenland.

[The_Global_Warmer]

The Merry Go Round of Positive Feedbacks is on going. This is just another major player revealing it self.

Things like this may go into explaining Greenland historically melting under not much warmer conditions.

[PhillipS]

Before you speak of the changes 'due to warming temperatures', you may wish to look at 80 Years Of Temperature Decline In Greenland.

Ah, there is nothing sweeter than fresh picked cherries, is there? Before you waste everyone's time, and embarass yourself in the process, by posting disinformation from denialist blogs, you may wish to check the actual research.

A quick search with Google Scholar turned up the peer-reviewed research on Greenland's temperature trends. Here is the abstract from Box 2001,Survey of Greenland instrumental temperature records: 1873–2001:

Temporal and spatial variability are analysed in Greenland instrumental temperature records from 24 coastal and three ice sheet locations. Trends over the longest period available, 1873–2001, at Ilulissat/Jakobshavn indicate statistically significant warming in all seasons: 5°C in winter. Trends over the 1901–2000 century in southern Greenland indicate statistically significant spring and summer cooling. General periods of warming occurred from 1885 to 1947 and 1984 to 2001, and cooling occurred from 1955 to 1984. The standard period 1961–90 was marked by 1–2°C statistically significant cooling. In contrast to Northern Hemisphere mean temperatures, the 1990s do not contain the warmest years on record in Greenland. The warmest years in Greenland were 1932, 1947, 1960, and 1941. The coldest years were 1918, 1984, 1993, and 1972, several of which coincide with major volcanic eruptions. Over 1991–2000, statistically significant 2–4°C warming was observed in western Greenland, 1.1°C warming at the ice sheet summit (3200 m), although this is statistically insignificant. Annual temperature trends are dominated by winter variability. Much of the observed variability is shown to be linked with the North Atlantic oscillation (NAO), sea ice extent, and volcanism. The correlation of coastal temperature anomalies with the NAO is statistically significant, in autumn and winter at western and southern sites. Warming from 1873 to 1930 and subsequent cooling persists after the removal of the NAO signal. Temperature trends are often opposite between west and east Greenland. This apparent teleconnection is spurious, however, given insignificant east–west correlation values. Frequency peaks correspond with periods of 3.7, 14.3, 9.1, 5.5–6.0, 11.1, and 7.1 years in both temperature and NAO. Copyright © 2002 Royal Meteorological Society.

This paper has been cited 115 times, which I take to mean that other scientists have found it informative. If you have any interest in reality rather than denialist nonsense there is a lot more data available on-line.

[Kelathos]

Two things,

First, your own refrence shows that 5°C spike in temperature occuring entirely between 1915-1935, before CO2 would seriously enter the equation.

Second, there is yet more data from your link with relatively similar trend lines to the GISS data I linked.

Cite the Box 2001, Survey of Greenland all you wish, it does not appear to refute that Greenland was warmer 80 years ago.

[rygar]

Ah, there is nothing sweeter than fresh picked cherries, is there? Before you waste everyone's time, and embarass yourself in the process, by posting disinformation from denialist blogs, you may wish to check the actual research.

A quick search with Google Scholar turned up the peer-reviewed research on Greenland's temperature trends. Here is the abstract from Box 2001,Survey of Greenland instrumental temperature records: 1873–2001:

Temporal and spatial variability are analysed in Greenland instrumental temperature records from 24 coastal and three ice sheet locations. Trends over the longest period available, 1873–2001, at Ilulissat/Jakobshavn indicate statistically significant warming in all seasons: 5°C in winter. Trends over the 1901–2000 century in southern Greenland indicate statistically significant spring and summer cooling. General periods of warming occurred from 1885 to 1947 and 1984 to 2001, and cooling occurred from 1955 to 1984. The standard period 1961–90 was marked by 1–2°C statistically significant cooling. In contrast to Northern Hemisphere mean temperatures, the 1990s do not contain the warmest years on record in Greenland. The warmest years in Greenland were 1932, 1947, 1960, and 1941. The coldest years were 1918, 1984, 1993, and 1972, several of which coincide with major volcanic eruptions. Over 1991–2000, statistically significant 2–4°C warming was observed in western Greenland, 1.1°C warming at the ice sheet summit (3200 m), although this is statistically insignificant. Annual temperature trends are dominated by winter variability. Much of the observed variability is shown to be linked with the North Atlantic oscillation (NAO), sea ice extent, and volcanism. The correlation of coastal temperature anomalies with the NAO is statistically significant, in autumn and winter at western and southern sites. Warming from 1873 to 1930 and subsequent cooling persists after the removal of the NAO signal. Temperature trends are often opposite between west and east Greenland. This apparent teleconnection is spurious, however, given insignificant east–west correlation values. Frequency peaks correspond with periods of 3.7, 14.3, 9.1, 5.5–6.0, 11.1, and 7.1 years in both temperature and NAO. Copyright © 2002 Royal Meteorological Society.

This paper has been cited 115 times, which I take to mean that other scientists have found it informative. If you have any interest in reality rather than denialist nonsense there is a lot more data available on-line.

Whole post was ignored because you attack other people. Cut out the nonsense and maybe someone will listen to you.

I really find myself being swayed by some of the folks here who are greatly concerned about Global Warming, but then I read posts like this and I end up stereotyping all if you in to the same bucket - little girls screaming that the sky is falling. It is impossible to read the forum when half the alarmists act like children.

Oh, and the data from the chart was from NASA no?

[WeatherRusty]

Greenland is one area of the northern hemisphere which has not kept up with the general warming of the overall hemisphere. It is warming, melting and losing ice mass. However, it been equally as warm if not warmer early in the past century. This is not unusual, as U.S. high temperature records go back to the 1930's.

AGU (a bit dated)

Discovery

[WeatherRusty]

Whole post was ignored because you attack other people. Cut out the nonsense and maybe someone will listen to you.

I really find myself being swayed by some of the folks here who are greatly concerned about Global Warming, but then I read posts like this and I end up stereotyping all if you in to the same bucket - little girls screaming that the sky is falling. It is impossible to read the forum when half the alarmists act like children.

Oh, and the data from the chart was from NASA no?

Emotions run high regarding AGW. People may act a little "over the top" at times. Most the the posters currently in here are solid contributers. Try to look past the emotion if you can. We who accept the basic science underlying AGW theory are frustrated by the political/industry disinformation machine of opinion which is mixed in with the honest skeptics.

[PhillipS]

Whole post was ignored because you attack other people. Cut out the nonsense and maybe someone will listen to you.

I really find myself being swayed by some of the folks here who are greatly concerned about Global Warming, but then I read posts like this and I end up stereotyping all if you in to the same bucket - little girls screaming that the sky is falling. It is impossible to read the forum when half the alarmists act like children.

Oh, and the data from the chart was from NASA no?

I'm sorry you feel that I always attack other people. I feel that I respond to serious posts with respect - but I will allow that I have room for improvement. And I certainly respond to nonsense with ridicule. That is all it deserves.

On my post you quoted, I was responding to a person trolling and serving up denialist nonsense in what has otherwise been a pretty interesting thread. Kelathos linked to a denialist webiste, specifically to a blog post in which two Greenland temperature records were cherrypicked from more than two dozen temperature records available, and then claimed the results covered all of Greenland. Which, of couse, they don't. Cherrypicking is fundamentally dishonest,

Nor are the charts shown on the blog post from NASA GISS. Check for yourself by following the links in the blog post. The underlying data may have come from GISS, but the charts have been altered and overlain with a misleading linear trend lines. To falsely attribute those charts to NASA. is blatently dishonest.

So, by almost any standard Kelathos' post was a poor one. So why don't you criticize him as you have criticized me? You seem to use a double standard in your assessment of posters.

[PhillipS]

Two things,

First, your own refrence shows that 5°C spike in temperature occuring entirely between 1915-1935, before CO2 would seriously enter the equation.

Second, there is yet more data from your link with relatively similar trend lines to the GISS data I linked.

Cite the Box 2001, Survey of Greenland all you wish, it does not appear to refute that Greenland was warmer 80 years ago.

You are right, there are better research papers I should have referenced. For example, Hanna et al, 2007, Increased Runoff from Melt from the Greenland Ice Sheet: A Response to Global Warming, is more recent and relevant. Here is Figure 2 from the paper:

Granted, it shows the summertime temps, but those encompass the melt season which is the topic of this thread.

[rygar]

I'm sorry you feel that I always attack other people. I feel that I respond to serious posts with respect - but I will allow that I have room for improvement. And I certainly respond to nonsense with ridicule. That is all it deserves.

On my post you quoted, I was responding to a person trolling and serving up denialist nonsense in what has otherwise been a pretty interesting thread. Kelathos linked to a denialist webiste, specifically to a blog post in which two Greenland temperature records were cherrypicked from more than two dozen temperature records available, and then claimed the results covered all of Greenland. Which, of couse, they don't. Cherrypicking is fundamentally dishonest,

Nor are the charts shown on the blog post from NASA GISS. Check for yourself by following the links in the blog post. The underlying data may have come from GISS, but the charts have been altered and overlain with a misleading linear trend lines. To falsely attribute those charts to NASA. is blatently dishonest.

So, by almost any standard Kelathos' post was a poor one. So why don't you criticize him as you have criticized me? You seem to use a double standard in your assessment of posters.

I can tolerate ignorance, I can't tolerate dueschness. We should all try to be more like Don in this forum - I have never once seen him speak out of turn, even when a denialist clearly goes off the deep end.