UPDATE: see this new article on the issue,
“Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time,” says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data.
Extent of surface melt over Greenland’s ice sheet on July 8 (left) and July 12 (right). Measurements from three satellites showed that on July 8, about 40 percent of the ice sheet had undergone thawing at or near the surface. In just a few days, the melting had dramatically accelerated and an estimated 97 percent of the ice sheet surface had thawed by July 12. In the image, the areas classified as “probable melt” (light pink) correspond to those sites where at least one satellite detected surface melting. The areas classified as “melt” (dark pink) correspond to sites where two or three satellites detected surface melting. The satellites are measuring different physical properties at different scales and are passing over Greenland at different times. As a whole, they provide a picture of an extreme melt event about which scientists are very confident. Credit: Nicolo E. DiGirolamo, SSAI/NASA GSFC, and Jesse Allen, NASA Earth Observatory
I covered this over the weekend when Bill McKibben started wailing about the albedo going off the charts. I thought it might be soot related. The PR below and quote above is from NASA Goddard. I had to laugh at the title of their press release, where they cite “Unprecedented Greenland Ice Sheet Surface Melt”, then contradict themselves when the main researcher goes on to say “melting events of this type occur about once every 150 years on average. With the last one happening in 1889“. Do these guys even read their own press releases? Climatologist Pat Michaels concurs saying: “Apparently NASA should start distributing dictionaries to the authors of its press releases.”
I’ve sent off a note to the NASA writer, seen here. Maybe she’ll get the headline fixed.
That, and they seem surprised that the Greenland ice sheet would suddenly start melting in summer. Though, not every part of the ice sheet is melting right now, so perhaps their calibrations might be a bit off:
There may have been a brief few days of melt, but it appears to be over:
Satellites See Unprecedented Greenland Ice Sheet Surface Melt
For several days this month, Greenland’s surface ice cover melted over a larger area than at any time in more than 30 years of satellite observations. Nearly the entire ice cover of Greenland, from its thin, low-lying coastal edges to its two-mile-thick center, experienced some degree of melting at its surface, according to measurements from three independent satellites analyzed by NASA and university scientists.
On average in the summer, about half of the surface of Greenland’s ice sheet naturally melts. At high elevations, most of that melt water quickly refreezes in place. Near the coast, some of the melt water is retained by the ice sheet and the rest is lost to the ocean. But this year the extent of ice melting at or near the surface jumped dramatically. According to satellite data, an estimated 97 percent of the ice sheet surface thawed at some point in mid-July.
Researchers have not yet determined whether this extensive melt event will affect the overall volume of ice loss this summer and contribute to sea level rise.
“The Greenland ice sheet is a vast area with a varied history of change. This event, combined with other natural but uncommon phenomena, such as the large calving event last week on Petermann Glacier, are part of a complex story,” said Tom Wagner, NASA’s cryosphere program manager in Washington. “Satellite observations are helping us understand how events like these may relate to one another as well as to the broader climate system.”
Son Nghiem of NASA’s Jet Propulsion Laboratory in Pasadena, Calif., was analyzing radar data from the Indian Space Research Organisation’s (ISRO) Oceansat-2 satellite last week when he noticed that most of Greenland appeared to have undergone surface melting on July 12. Nghiem said, “This was so extraordinary that at first I questioned the result: was this real or was it due to a data error?”
Nghiem consulted with Dorothy Hall at NASA’s Goddard Space Flight Center in Greenbelt, Md. Hall studies the surface temperature of Greenland using the Moderate-resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra and Aqua satellites. She confirmed that MODIS showed unusually high temperatures and that melt was extensive over the ice sheet surface.
Thomas Mote, a climatologist at the University of Georgia, Athens, Ga; and Marco Tedesco of City University of New York also confirmed the melt seen by Oceansat-2 and MODIS with passive-microwave satellite data from the Special Sensor Microwave Imager/Sounder on a U.S. Air Force meteorological satellite.
The melting spread quickly. Melt maps derived from the three satellites showed that on July 8, about 40 percent of the ice sheet’s surface had melted. By July 12, 97 percent had melted.
This extreme melt event coincided with an unusually strong ridge of warm air, or a heat dome, over Greenland. The ridge was one of a series that has dominated Greenland’s weather since the end of May. “Each successive ridge has been stronger than the previous one,” said Mote. This latest heat dome started to move over Greenland on July 8, and then parked itself over the ice sheet about three days later. By July 16, it had begun to dissipate.
Even the area around Summit Station in central Greenland, which at 2 miles above sea level is near the highest point of the ice sheet, showed signs of melting. Such pronounced melting at Summit and across the ice sheet has not occurred since 1889, according to ice cores analyzed by Kaitlin Keegan at Dartmouth College in Hanover, N.H. A National Oceanic and Atmospheric Administration weather station at Summit confirmed air temperatures hovered above or within a degree of freezing for several hours July 11-12.
“Ice cores from Summit show that melting events of this type occur about once every 150 years on average. With the last one happening in 1889, this event is right on time,” says Lora Koenig, a Goddard glaciologist and a member of the research team analyzing the satellite data. “But if we continue to observe melting events like this in upcoming years, it will be worrisome.”
Nghiem’s finding while analyzing Oceansat-2 data was the kind of benefit that NASA and ISRO had hoped to stimulate when they signed an agreement in March 2012 to cooperate on Oceansat-2 by sharing data.
============================================
h/t to WUWT reader Ole Heinrich
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As for your table problem, I have the same problem. Perhaps one of our commenters can offer a solution. -REP]
Use the “code” HTML tag, which sets all characters at the same width. Space out entries with underscores as needed instead of multiple spaces as multiple spaces are auto-collapsed into one space. Due to quirks displaying, it works best with start tag on same line as beginning of content, with a return between end of content and close tag. From Entropic Mann comment, replace brackets with left/right arrows:
(start)
[code]Date Temp. anomaly Change to 2011
1996 +0.29 0.51 – 0.29 = +0.20
1997 +0.41 0.51 – 0.41 = +0.10
1998 +0.58 0.51 – 0.58 = -0.07
1999 +0.33 0.51 – 0.33 = +0.18
2000 +0.35 0.51 – 0.35 = +0.16
2010 +0.62
2011 0.51
[/code]
(end)
Result:
(start)
Date Temp. anomaly Change to 2011
1996 +0.29 0.51 – 0.29 = +0.20
1997 +0.41 0.51 – 0.41 = +0.10
1998 +0.58 0.51 – 0.58 = -0.07
1999 +0.33 0.51 – 0.33 = +0.18
2000 +0.35 0.51 – 0.35 = +0.16
2010 +0.62
2011 0.51
(end)
Although I think it should have been:
Year__Anomaly °C__Difference from 2011
1996__+0.29_______+0.22
1997__+0.41_______+0.10
1998__+0.58_______-0.07
1999__+0.33_______+0.18
2000__+0.35_______+0.16
2010__+0.62_______-0.11
2011__+0.51_______+0.00
…or whatever the heck it was he was trying to show.
Re my last comment:
My example using brackets is appearing on my end like code on line printer greenbar paper. (Ah, how I miss having yards of continuous code with plenty of space for scribbled corrections and notes…) Must be a new wordpress thing, it shows up as a page element with clickable options on mouseover.
So here is the example using braces:
(start)
{code}Date Temp. anomaly Change to 2011
1996 +0.29 0.51 – 0.29 = +0.20
1997 +0.41 0.51 – 0.41 = +0.10
1998 +0.58 0.51 – 0.58 = -0.07
1999 +0.33 0.51 – 0.33 = +0.18
2000 +0.35 0.51 – 0.35 = +0.16
2010 +0.62
2011 0.51
{/code}
(end)
kadaka (KD Knoebel)
Thank you for the table idea. I’m afraid I gave up programming in the 1980’s when it became obvious that I could be a science teacher or a programmer, but did not have time to be both.
As for my purpose, Smokey claimed that the apparant cooling observed by comparing the global temperatures for 1998 and 2011 showed that global warming had stopped.
My table, before it got squashed, demonstrated that if he had taken any of the two years before or after he would have seen continued warming. Whoever chose 1998 was cherrypicking a date which gave the desired anti-warming result.
Date_ Temp. anomaly_Change to 2011
1996 ____+0.29____ 0.51 – 0.29 = +0.20
1997 ____+0.41____ 0.51 – 0.41 = +0.10
1998 ____+0.58____ 0.51 – 0.58 = -0.07
1999 ____+0.33____ 0.51 – 0.33 = +0.18
2000 ____+0.35____ 0.51 – 0.35 = +0.16
2010 ____+0.62
2011____+0.51
Incidentally, if you end on 2010 instead of 2011, all the changes show warming.
Since you can show the 21st century as warming, cooling or static by picking the combination of dates that suits your desire, this technique is useless as a serious analytical tool. Something more sophisticated, and independant of observer bias, would be needed. Statisticians to the fore, please.
Wrong!
There are 13 series in this graph, only one ends in 2011 and it is you that is cherry picking it so you can throw out nonsense about positive, negative, positive PDO phases and step changes. Nine of those series terminate before 1998 (so the step change is not a factor), the end dates are evenly spaced between 1951 and 1996 (so they can’t all benefit from positive, negative, positive PDO phases) and each series shows a greater rate of warming than those prior to it. You can hide behind the noise and cherry pick all you want, but the fact remains: the rate of warming is accelerating.
From Entropic man on July 26, 2012 at 3:35 pm:
Umm… No. No he didn’t.
From Smokey on July 24, 2012 at 3:49 pm:
He linked to a graph showing the WoodForTrees Temperature Index from 1997.5 to current end of records. If you would have clicked his link then clicked on “Raw data” you would have seen this:
It’s a composite index.
And from that, you’ve dreamed up that Smokey compared the 1998 annual number to 2011’s, and proceeded to “disprove” your imaginary situation by manipulating individual annual figures, during which you claimed Smokey used GISTEMP then drew your “proof” from those numbers.
(And twice now you’ve claimed 0.51-0.29 = 0.20, not 0.22. I corrected that once for my “should be” example. Don’t you check your math?)
So you set up a falsehood, disproved the falsehood, gave that as “proof” Smokey was cherrypicking.
There must be very low standards for evidence against skeptics at ReallyRealClimate if you think “proof” like that is acceptable.
Or… You could simply look at the trends.
Entropic man says:
July 26, 2012 at 3:35 pm
kadaka (KD Knoebel)
…
As for my purpose, Smokey claimed that the apparant cooling observed by comparing the global temperatures for 1998 and 2011 showed that global warming had stopped.
If we were talking about the period 1975-2000, rather than 2000 onwards, there would not be a discussion of trend or no trend based on including or excluding a year or two at either end. The warming at the end of the 20th century was steep and uncontroversial. But since 2000 it has levelled off so that now we can have these arcane arguments about cherrypicking years.
Can you help us by explaining why the above is clear evidence for the acceleration of global warming, since the AGW camp, not satisfied with arguing the uncontroversial and trivial fact that climate has warmed in the last 40 years, now need it to be accelerating to further their alarmist goals.
The indication from the Greenland ice core of a periodic 115 year interval sharp melting on Greenland, is incredibly interesting. What mechanism can cause this? Does it point to astrophysical or orbital alignments, in which case it opens the possibility of other decadal and century scale climate oscillations being astrophysically forced. This has huge implications for climate science. Or is there some other explanation? How good is the evidence for the 115 year periodicity? Is it by chance over the last few centuries or is it a real phenomenon?
The retro-temporal causal consequences of that CO2 stuff is trooly confounding!
Kevin MacDonald says:
“…the fact remains: the rate of warming is accelerating.”
That is not a “fact” at all. That is an artifact of a zero baseline chart.
That is not science, that is pseudo-science. Big difference.
kadaka (KD Knoebel) says:
July 26, 2012 at 10:32 pm
“Or… You could simply look at the trends”
No, that’s not enough!
A couple of days posting here has shown me why the sceptics have made so little progress against the climate change consensus.
You can’t just look at the trends. You have to show that the trend you claim to see is there to the standards demanded by peer review. That means well designed experiments, valid statistics and significances as good as your data will allow.
Advice from a decrepit old scientist; put aside the conspiracy theories, snide remarks and junk science which permeate these pages. If you are correct, you should be able to show it because your science fits the data better than theirs.
Take this claim that there has been no warming for 15 years. Show me a proper peer reviwed statistical analysis giving a better than 50% probability that this null hypotheses is correct. That would do more to convince me than any amount of arm waving.
This is not a debate to be won by the man with the best soundbites. It is a scientific study won by the hypotheses best shown to fit reality.
Decrepit, indeed. Trying the Trenberth Twist, are we? News Flash: the Null is assumed until disproven. There is no onus on anyone, skeptics or other, to “prove” the Null.
Entropic man says:
July 24, 2012 at 12:23 pm
The hot high pressure air which moved over Greenland in the second week in July coincided with the close of the US East Coast heat wave, which may be where the hot air came from.
If this is normally a very rare weather pattern, we probably wont see its like again for some time. If we start seeing repeats every few years, then it may signify a genuine change in North American climate. It does provide an explanation for that sudden drop in albedo.
* * *
You correctly point out; “sudden drop in albedo”.
If a marginally snow-covered area warms, snow tends to melt, lowering the albedo, and hence leading to more snow melt. (the ice-albedo positive feedback).
Cryoconite, powdery windblown dust containing soot, sometimes reduces albedo on glaciers and ice sheets.
http://ngm.nationalgeographic.com/2010/06/melt-zone/balog-photography
http://wattsupwiththat.com/2012/07/21/greenland-ice-sheet-albedo-drops-off-the-bottom-of-the-chart-but-look-closer-as-to-why/
kadaka (KD Knoebel) says:
July 25, 2012 at 11:58 am
….if you miss a doublequote in the “href=” link, defaults to the page the link is posted on. I’ve noticed you’ve been doing that a lot lately, when your links show up with the “recently viewed” coloration and I check them.
You’re good, you can do better. Please doublecheck before posting. Thank you.
_________________________
We found the internet connection has been dropping “packets” recently so what I write and send are sometimes two different things. But yes I will try double checking more.
I am mentioning this because I am sure we are not the only people with the problem.
(My computer is a real dinosaur and I can not run a word processor and look at the internet at the same time which makes editing a real bear.)
Gail;
Re editing, etc.: acquire (~$35) ClipMate. Its main function is to save copied material for re-use for as long as you want (I’ve set mine for about 8 yrs!), but it also permits direct creation of a new “Clip” which can be edited and then pasted by the usual keystrokes wherever you want.
It is without exception the most used and useful internet and word processing tool I have ever come across.
clipmate.com, 30 day free trial.
94% of the ice has melted? This statement does not mean that 94% of the ice is gone. No, 94% of the surface is seeing melt.