European satellite confirms UW numbers: Arctic Ocean is on thin ice
By Hannah Hickey (via university of Washington press release)
The September 2012 record low in Arctic sea-ice extent was big news, but a missing piece of the puzzle was lurking below the ocean’s surface. What volume of ice floats on Arctic waters? And how does that compare to previous summers? These are difficult but important questions, because how much ice actually remains suggests how vulnerable the ice pack will be to more warming.
New satellite observations confirm a University of Washington analysis that for the past three years has produced widely quoted estimates of Arctic sea-ice volume. Findings based on observations from a European Space Agency satellite, published online in Geophysical Research Letters, show that the Arctic has lost more than a third of summer sea-ice volume since a decade ago, when a U.S. satellite collected similar data.
Combining the UW model and the new satellite observations suggests the summer minimum in Arctic sea ice is one-fifth of what it was in 1980, when the model begins.
“Other people had argued that 75 to 80 percent ice volume loss was too aggressive,” said co-author Axel Schweiger, a polar scientist in the UW Applied Physics Laboratory. “What this new paper shows is that our ice loss estimates may have been too conservative, and that the recent decline is possibly more rapid.”
The system developed at the UW provides a 34-year monthly picture of what’s happening to the total volume of Arctic sea ice. The Pan-Arctic Ice Ocean Modeling and Assimilation System, or PIOMAS, combines weather records, sea-surface temperature and satellite pictures of ice coverage to compute ice volume. It then verifies the results with actual thickness measurements from individual moorings or submarines that cruise below the ice.
“Because the ice is so variable, you don’t get a full picture of it from any of those observations,” Schweiger said. “So this model is the only way to reconstruct a time series that spans multiple decades.”
The UW system also checks its results against five years of precise ice thickness measurements collected by a specialized satellite launched by NASA in 2003. The Ice, Cloud, and Land Elevation Satellite, or ICESat, measured ice thickness across the Arctic to within 37 centimeters (15 inches) until spring of 2008.
The U.K.’s CryoSat-2 satellite resumed complete ice thickness measurements in 2010; this is the first scientific paper to share its findings about the recent years of record-low sea ice.
Between 2008 and now, the widely cited UW figures have generated some controversy because of the substantial ice loss they showed.
“The reanalysis relies on a model, so some people have, justifiably, questioned it,” Schweiger said. “These data essentially confirm that in the last few years, for which we haven’t really had data, the observations are very close to what we see in the model. So that increases our confidence for the overall time series from 1979 to the present.”
Arctic sea ice is shrinking and thinning at the same time, Schweiger explained, so it’s normal for the summer ice volume to drop faster than the area covered, which today is about half of what it was in 1980.
Schweiger cautioned that past trends may not necessarily continue at the same rate, and predicting when the Arctic might be largely ice-free in summer is a different question. But creating a reliable record of the past helps to understand changes in the Arctic and ultimately helps to better predict the future.
“One question we now need to ask, and can ask, is what are the processes that are driving these changes in the ice? To what degree is it ocean processes, to what degree is this in the atmosphere?” Schweiger said. “I don’t think we have a good handle on that yet.”
The UW system was created by co-author Jinlun Zhang, an oceanographer at the Applied Physics Laboratory. The UW portion of the research was funded by NASA and the Office of Naval Research.
Other co-authors are first author Seymour Laxon, Katharine Giles, Andy Ridout, Duncan Wingham and Rosemary Willatt at University College London; Robert Cullen and Malcolm Davidson at the European Space Agency; Ron Kwok at NASA’s Jet Propulsion Laboratory; Christian Haas at York University in Canada; Stefan Hendricks at the Alfred Wegener Institute for Polar and Marine Research in Germany; Richard Krishfield at Woods Hole Oceanographic Institution; Sinead Farrell at the University of Maryland; and Nathan Kurtz at Morgan State University in Baltimore.
###
OK, so the question now they say is:
“One question we now need to ask, and can ask, is what are the processes that are driving these changes in the ice? To what degree is it ocean processes, to what degree is this in the atmosphere?” Schweiger said. “I don’t think we have a good handle on that yet.”
Those are good questions. Soot, in addition to cyclical ocean and atmospheric processes should also be investigated, since it has a strong ability to absorb sunlight and be a forcing of its own.
I also wonder if this isn’t some sort of natural cyclic occurance that we are just now becoming aware of due to our space based remote sensing capabilities. We really don’t have any good data beyond the satellite era, but we do have some older interesting anecdotal evidence such as this story: You ask, I provide. November 2nd, 1922. Arctic Ocean Getting Warm; Seals Vanish and Icebergs Melt.
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From KR’s link:
This ice loss appears to be unmatched over at least the last few thousand years and unexplainable by any of the known natural variabilities.
That is the old Argumentum ad Ignorantium fallacy: ‘Since I don’t have the answers, I am guessing that natural variability must be ruled out’.
There is entirely too much of this sort of pseudo-scientific nonsense in climate ‘science’. The guy just doesn’t know, so he is winging it. Tap dancing, in place of testable, empirical evidence.
KR’s previous link is even worse:
…both the duration and magnitude of the current decline in sea ice seem to be unprecedented for the past 1,450 years.
That means, of course, that the parameters were exceeded 1,450 years ago — when CO2 was very low… which makes a mockery of his assertion that current sea ice levels are “consistent” with AGW. We can’t even measure AGW, yet this rent-seeker is making assertions about it. Zero credibility, there. Try to at least find someone who uses logical consistency.
David Hughes says: February 13, 2013 at 4:13 pm
I remember seeing pictures of one of our nuclear subs surfaced in open water at the North Pole in ~1958. Sounds like with only 32 yrs of satellite data, this is a lot about absolutely nothing….
David, while I agree that anecdotal evidence indicates modern arctic ice summer decline is not unprecedented, I’m not sure we can in any way trust cold war era propaganda photographs and their accompanying text in the newspaper. I’d love to see an officer or navigator who was on those subs at the time come forward and confirm the position where those photos were taken. If it was really at or near the pole, that would be convincing.
“One question we now need to ask, and can ask, is what are the processes that are driving these changes in the ice? To what degree is it ocean processes, to what degree is this in the atmosphere?” Schweiger said. “I don’t think we have a good handle on that yet.”
Jaw drops to table, to floor, and bounces off the wall!!!!
Schweiger speaks the words of a genuine scientist!!!! WUWT’s influence is spreading. Hope he doesn’t get fired. Schweiger will never be invited to a Hansen sit-in.
Steven Mosher says: February 13, 2013 at 3:58 pm
“We already know that arctic ice has been low in the past. This obsession is beyond ridiculous.”
really? is that settled science? do we really KNOW this? tsk tsk skepticism out the door
hmm, lets see some data on area, extent and volume….
While I agree (partially, and for once) with Mosh, that ‘anecdotal evidence’ is not settled science, it cannot be denied that such anecdotal evidence does exist, and that perhaps the CAGW crowd are more in the wrong in their continued implications that these events are unprecedented. The historical data he demands is in short supply.
D.B. Stealey says: (to Steve Mosher says:“your first paper cited was a total FAIL.”)
“I suggest you take it up with the NGU. It’s their peer reviewed paper.”
And: (to Steve Mosher says:“Second paper was also a fail… where is your skepticism”)
“I suggest you take it up with the journal Science. It is their published, peer reviewed paper.”
Umm, Mosher is not saying the papers are bad; he is saying they are irrelevant for your point that there was less ice then. Same for the third paper.
And as for nuc subs in the open water in the 50s or 60s (of course there was some open water in the summer, even then), I remember the sub people saying they have to look for places to surface because the ice was too thick/old to break through in many places…and the same people commenting that they dont need to do that nowadays, even in the winter.
Theo Goodwin says: February 13, 2013 at 6:31 pm
“One question we now need to ask, and can ask, is what are the processes that are driving these changes in the ice? To what degree is it ocean processes, to what degree is this in the atmosphere?” Schweiger said. “I don’t think we have a good handle on that yet.”
…
Schweiger speaks the words of a genuine scientist!!!! WUWT’s influence is spreading…”
Well said Theo. Once, every scientific article on climate and weather seemed to have a paragraph saying something along the lines of; ” … but [….] will get a lot worse in the future due to the effects of CAGW…”
I’d formed the opinion that this had become a standard insertion demanded by reviewers, but maybe the above indicates a return to the normal approach to science.
trafamadore,
Recall that I was helpfully providing information that Steve Mosher requested.
Now, why don’t you try to answer dp’s question: tell us how much Arctic ice is the right amount? Don’t worry about the Antarctic, just tell us how much sea ice the Arctic is supposed to have. A sport like you should have the answer right at your fingertips.
phlogiston says:
February 13, 2013 at 3:43 pm
“If the current switch to La Nina ENSO dominance continues, and the AMO enters its down-swing, then the legacy warm water will run out and the Arctic ice will recover.”
Recover? Why does everyone assume conditions are abnormal? I can as easily proclaim the last 30 years of ice extent, area and volume decline IS the recovery to arctic-normal conditions.
The topic has lost some appeal, because
the main driver is AMO and natural
http://hidethedecline.eu/media/ARUTI/Coast/fig4a.jpg
the second main driver is black carbon
http://judithcurry.com/2013/02/08/open-thread-weekend-8/#comment-293710
there are significant negative feedbacks, such as open sea heat loss and increased northern hemisphere snow cover
and everything else is not really important, except perhaps the sun.
Currently, not much to worry about, just clean up black carbon and keep an eye on the sun.
Steven Mosher says:
February 13, 2013 at 3:58 pm
“We already know that arctic ice has been low in the past. This obsession is beyond ridiculous.”
really? is that settled science? do we really KNOW this? tsk tsk skepticism out the door
hmm, lets see some data on area, extent and volume.
Reading this and your subsequent responses, it comes across that your request for “proof” of what happened in the past (i.e., before the satellite record began) cannot be ever be satisfied, because the only evidence that exists is anecdotal. Kindly clarify if you are suggesting the null hypothesis is that arctic ice has never been as low as it currently is in the past and if you’re implying there is no acceptable data that could be used to falsify your hypothesis.
Regarding Mosher:
For those of you who are trying to convince Mosher that there was less Arctic ice in the past, I think you are overlooking something. The topic in this forum is sea ice volume, not sea ice extent. The only data about Arctic sea ice volume is from satellites and dates only to 2003. Mosher has you on a technicality, so to speak. No matter what anecdotal evidence you cite, it is not evidence of volume.
On the other side of the coin, ten years of satellite records is not something to get excited about. Read about the satellites, click in the article above, and learn about their techniques. They estimate volume from surface features of the ice.
As scientist Schweiger said, this data gives scientists some wonderful questions to answer. It does not answer even one question about causality.
A pretty good discussion of the satellites is:
http://www.jpl.nasa.gov/news/news.php?release=2013-057
From the dastardly (but easy to reference) wikipedia:
http://en.wikipedia.org/wiki/Properties_of_water
As the surface of salt water begins to freeze (at −1.9 °C for normal salinity seawater, 3.5%) the ice that forms is essentially salt free with a density approximately equal to that of freshwater ice. This ice floats on the surface and the salt that is “frozen out” adds to the salinity and density of the seawater just below it, in a process known as brine rejection. This denser saltwater sinks by convection and the replacing seawater is subject to the same process. This provides essentially freshwater ice at −1.9 °C on the surface. The increased density of the seawater beneath the forming ice causes it to sink towards the bottom.
On average the arctic ocean is about 1000 meters deep. Under water currents mess with all this of course, but stop and think about the process. Going from half a degree above freezing to 1/2 degree below freezing at the surface means 1,000 meters of water are giving up a stupendous amount of heat. But we’re all wound up about the ice being 10 cm thick or 20 cm thick? It could be 10 meters thick. The amount of energy change compared to the water column itself is minuscule.
The meme that a submarine surfaced in open water at the North Pole in 1958 has a thousand lives. It’s a zombie lie. http://reallysciency.blogspot.com/2012/01/zombie-lies.html
The USS Skate did surface at the North Pole in 1959 – but it had to break through ice in a frozen lead to do so. In 1960 the Commander of the Skate, James Calvert, wrote Surface At The Pole, Commander James Calvert USN, The Extraordinary Voyages of the USS Skate. In it he details how the Skate didn’t find any open water on their 1959 cruise until several days *after* they surfaced at the North Pole – and when they did it was hundreds of miles from the pole and the ‘open water’ was a hole in the ice about two-feet in diameter!
This stuff is so easy to verify you have to *want* to believe the lies and actively turn a blind eye to the truth. There’s really no other plausible explanation.
Re:davidmhoffer says: Going from half a degree above freezing to 1/2 degree below freezing at the surface means 1,000 meters of water are giving up a stupendous amount of heat.
No, that’s not the way it works. The Arctic Ocean is composed of layers of water with different properties, and at the base of the surface layer there is a big jump in density (known as a pycnocline), so convection only involves the surface layer down to that level (about 100-150 metres).
A complete explanation of how sea ice forms can be found at http://www.arctic.noaa.gov/essay_wadhams.html
Theo Goodwin says:
February 13, 2013 at 7:59 pm
The only data about Arctic sea ice volume is from satellites and dates only to 2003. Mosher has you on a technicality, so to speak. No matter what anecdotal evidence you cite, it is not evidence of volume.
———————–
Wrong.
From 1957:
“Northpole ice has decreased by something as 40% in volume…this has been going on for 30-40 years”
http://i680.photobucket.com/albums/vv161/Radiant_2009/popularmechanics1957-2.jpg
In addition (my prediction is) winter maximum extent will go back to the anomaly (longer term average) in less than 5 years.
Not much of a prediction you might say when Arctic sea ice area was above the anomaly at maximum for both 2010 and 2012. But I posted that before I checked the data, so it sorta counts.
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png
Newspapers were full of stories reporting record Arctic warmth and northerly sea ice extent in the early 1920s, and again in 1939 (http://trove.nla.gov.au/ndp/del/article/94847838):
THE WORLD WARMS UP
Scientists’ Explorations in the Arctic
Extraordinary phenomena have been observed in the Arctic during the last 20 years. The southern boundaries of the icefields have retreated considerably northward, the temperature of the atmosphere has risen, and warmth-loving fish and other creatures have begun to make their way north.
The summer of 1936 was very warm in Eastern Greenland, and from the beginning of July onward the ice-crust along the coast retreated as far north as 72 deg. latitude; farther north than anyone could remember its having shrunk before. June of the same year was exceptionally warm in Leningrad – warmer than any other June of the 20th century.
And in 1932 the small research vessel Knipovich succeeded in sailing all the way round Franz-Josef Land for the first time in the history of Polar navigation. During the same season the steamer Sibiryakov rounded the north of North-East Land, and in 1935 the Sadko achieved a feat which any Polar explorer of the past would have declared impossible – she sailed through open sea from the northern extremity of Novaya Zemblya to the northern extremity of North-East Land, and then reached latitude 82 deg. 84 min. north. Never before in the history of Arctic exploration had a vessel sailed freely on open seas in such northerly latitudes.
Arctic Warmth Increasing
Soviet scientists were the first to draw attention to the increasing warmth of the Arctic. In 1921 Professor N. M. Knipovich pointed out that the waters of the Barents Sea had grown perceptibly warmer since the investigations he had made in that area at the beginning of the present century. Indeed, of recent years, this rise in the atmospheric temperature of the Arctic regions had been considerable. In March 1920 the thermometer rose 10 degrees above normal in Novaya Zemblya and in Leningrad the same March achieved a record temperature for middle of the last century.
Even the average winter during the last 20 years has been much milder. Icebound rivers on the northern areas of Soviet Russia, for instance, are opening earlier on the average, and freezing over later.
Birds are arriving and vegetation blossoming earlier in the spring. In the Leningrad district in 1934 the bird-cherry was in flower by May 7 – half a month earlier than the normal time. And the cuckoo’s call is to be heard some 10 days earlier than it was in the middle of the last century. It seems, too, that the bounds of everlasting frost are retreating northward.
About a century ago the famous traveller Shrenk discovered that in the town of Mezen wells had to be dug through ground frozen all the year round. But an expedition sent out by the Soviet Academy of Sciences in 1933 found no frozen ground at all in Mezen; the limit of everlasting frost had retreated some 25 miles north of the town. Obviously the climate must have grown very much milder to thaw out the frosts of Mezen.
Of recent years, also, quite a number of warmth-loving fish and other organisms have made their way far to the north, along the coasts of Greenland, and eastwards into the Kara Sea. Formerly the salmon was not known at all east of the Barents Sea, but recently salmon, and also cod and herring, have been found in the Kara Sea. The mackerel, too, used never to be met with north of North Cape, but in 1937 I was sent a specimen caught off Novaya Zemblya, close to the entrance to the Strait of Matochkin Shar; while in 1933 the porpoise, which is not normally seen further east than the Kanm peninsula, was actually observed east of Taimir.
Earth’s Temperature Rises
This rise in temperature has also been going on all over the world. The average atmospheric temperature has risen not only in Europe and North America, but, most remarkable of all, in the Southern Hemisphere also – in Santiago de Chile, in Cape Town, and even in the tropics at Bombay and Batavia.
Nor has it grown warmer only in the plains; the rise has extended even to areas of high mountains. What, then, are the causes of this rise in the earth’s temperature? Not long ago it was thought that the growing warmth of the Arctic must be due in some ways to an increase in the influence of the Gulf Stream, But, apart from the fact that the Gulf Stream is only one of the factors influencing climate and weather in the north, the rise in temperature, as we have seen, is also noticeable in the tropics and in the Southern Hemisphere.
Obviously, that cannot be blamed on the Gulf Stream. We are witnessing, in fact, a change in climate which has affected almost the whole world – and naturally the Gulf Stream itself is being warmed by this general rise in temperature. The rise is being accompanied by a general intensification in the rate of circulation of our atmosphere, which in turn can only be caused by changes in physical conditions elsewhere than on the earth itself, such as an increase in the quantity of the solar heat received by the earth’s surface.
The quantity of solar energy received by the earth can be increased by two causes – a greater irradiation of heat on the part of the sun – or because cosmic space or the terrestrial atmosphere is becoming more absorptive of solar energy.
In the present state of scientific knowledge it is impossible to say which of these two alternatives more closely corresponds to the facts. It is equally impossible to say anything definite on the question of how long this rise in temperature will continue, whether it will continue at all, or whether the climate will soon return again to its normal condition.
In the post-Ice Age, 3000 to 5000 years ago, there was a period when the summer temperature was even hotter than it is today. But whether we are witnessing the reproach of another such period – or whether it is merely a question of a climatic variation which will only last a few decades – is a question which at present can not be answered.
Kevin O’Neill;
No, that’s not the way it works. The Arctic Ocean is composed of layers of water with different properties, and at the base of the surface layer there is a big jump in density (known as a pycnocline), so convection only involves the surface layer down to that level (about 100-150 metres).
>>>>>>>>>>>>>>>>>>.
I’ll take your word for it.
Which leaves a water column of 100 to 150 meters that still has to change temperature to support a few cm of ice. That water volume and the temperature change of it dwarfs the energy represented by phase change of water to ice in the ice layer.
Does anyone know the ice extent prior to the massive storm that destroyed so much of it 4th Aug-9th Aug last summer? If so it would be an intereesting projection to see where the ice would be now if it was not for that storm.
See Antartica is in good shape….also notice it is never discussed.
“Kevin O’Neill;
No, that’s not the way it works. The Arctic Ocean is composed of layers of water with different properties, and at the base of the surface layer there is a big jump in density (known as a pycnocline), so convection only involves the surface layer down to that level (about 100-150 metres).”
Instead of speaking from a position of authority you should provide a link to the essay from which you have quoted verbatim!
http://www.arctic.noaa.gov/essay_wadhams.html
Manfred says:
February 13, 2013 at 10:08 pm
From 1957:
“Northpole ice has decreased by something as 40% in volume…this has been going on for 30-40 years”
http://i680.photobucket.com/albums/vv161/Radiant_2009/popularmechanics1957-2.jpg
You claim that Theo Goodwin was wrong when he wrote “The only data about Arctic sea ice volume is from satellites and dates only to 2003. Mosher has you on a technicality, so to speak. No matter what anecdotal evidence you cite, it is not evidence of volume.”
Then you proceed to produce your quote. I’m sure popular mechanics was, in 1957 (a good year btw – I was born then!), a fine publication, but I question whether the seeking out of a Professor of Meteorology and getting a staff reporter to ask him loaded questions actually counts as evidence at all, especially since he went on to state “If this continues till (sic) the end of the century there will be very little summer ice in the Arctic, or only small patches of it.” That didn’t work out so well, did it.
Fwiw, I think that it’s way too early to be making any definitive pronunciations on Arctic sea ice volumes since (a) satelite measurements have only recently begun to be taken and (b) I have yet to see any definitive verification of the data. Because of that, anyone who makes any kind of claim about long term trends must, of necessity, be reliant on models and anecdotal evidence. That is as true for sceptics as it is for Mosher. 😉
The only problem with all this concentration on Min and Max is that woefully fails when analysing cyclic phenonema.
Normally, in most (all?) other areas of science when looking at cycles of any form then there are four points, not two, that are of primary interest.
The two other relevant points are the ‘zero or central crossing’ ones. These are the ‘central’ values about which Arctic Sea Ice oscillates. http://i46.tinypic.com/2ezgzk5.png
The precise timing of these ‘zero crossing’ points (as well as the timing of the Min & Max) along with the Min and Max range shows a more complex picture than just simply ‘all year larger’ or ‘all year smaller’ would suggest.
The best way to determine these ‘zero crossing’ points is to find parts of the signal which have the least varience year on year.
Those, for Arctic Sea Ice, appear to be ~21st May and 14th to 21st Dec.
” We really don’t have any good data beyond the satellite era,…”
We don’t know yet if we even have good data from the satellite era. Scientists and explorers of the days past were equally sure that they knew what they knew with their methodology back then. Modern instrumentation can lie every bit as well as ancient instrumentation. Apparently modern scientists can lie even better. So yes, there has been progress in scientific endeavour in the modern age, jut not the right kind.
@davidmhoffer says:
February 13, 2013 at 4:58 pm, February 13, 2013 at 8:34 pm & February 13, 2013 at 10:53 pm
@Kevin O’Neill says:
February 13, 2013 at 9:36 pm
@edcaryl says:
February 13, 2013 at 5:24 pm
So if the run-off from these Russian rivers in the past created a layer of fresh water on top of the Arctic. Wouldn’t that greatly improve ice forming?
And now that this run-off is greatly diminished, wouldn’t you expect thinner ice?