This fits right in to what I’ve been blogging about for two years. the 2007 record minimum ice extent was wind driven not melt driven. A significant portion of the ice did not melt in place. It was pushed south by the wind where it melted.
Here’s where the wind is a factor in pushing past the ice arches:
NASA Sees Arctic Ocean Circulation Do an About-Face
Arctic Sea ice loss – “it’s the wind” says NASA
Here’s where ice arches help: Update on Arctic sea ice melt – “Ice pockets choking Northern Passage”
Watch how ice flows in the Arctic: Arctic Sea Ice Time Lapse from 1978 to 2009 using NSIDC data
Today’s Press Release From JPL:
Missing ‘Ice Arches’ Contributed to 2007 Arctic Ice Loss
Animation: View animation (GIF 52 Mb) | View animation (GIF 13 Mb)
PASADENA, Calif. – In 2007, the Arctic lost a massive amount of thick, multiyear sea ice, contributing to that year’s record-low extent of Arctic sea ice. A new NASA-led study has found that the record loss that year was due in part to the absence of “ice arches,” naturally-forming, curved ice structures that span the openings between two land points. These arches block sea ice from being pushed by winds or currents through narrow passages and out of the Arctic basin.
Beginning each fall, sea ice spreads across the surface of the Arctic Ocean until it becomes confined by surrounding continents. Only a few passages — including the Fram Strait and Nares Strait — allow sea ice to escape.
“There are a couple of ways to lose Arctic ice: when it flows out and when it melts,” said lead study researcher Ron Kwok of NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “We are trying to quantify how much we’re losing by outflow versus melt.”
Kwok and colleagues found that ice arches were missing in 2007 from the Nares Strait, a relatively narrow 30- to 40-kilometer-wide (19- to 25-mile-wide) passage west of Greenland. Without the arches, ice exited freely from the Arctic. The Fram Strait, east of Greenland, is about 400 kilometers (249 miles) wide and is the passage through which most sea ice usually exits the Arctic.
Despite Nares’ narrow width, the team reports that in 2007, ice loss through Nares equaled more than 10 percent of the amount emptied on average each year through the wider Fram Strait.
“Until recently, we didn’t think the small straits were important for ice loss,” Kwok said. The findings were published this month in Geophysical Research Letters.
“One of our most important goals is developing predictive models of Arctic sea ice cover,” said Tom Wagner, cryosphere program manager at NASA Headquarters in Washington. “Such models are important not only to understanding changes in the Arctic, but also changes in global and North American climate. Figuring out how ice is lost through the Fram and Nares straits is critical to developing those models.”
To find out more about the ice motion in Nares Strait, the scientists examined a 13-year record of high-resolution radar images from the Canadian RADARSAT and European Envisat satellites. They found that 2007 was a unique year – the only one on record when arches failed to form, allowing ice to flow unobstructed through winter and spring.
The arches usually form at southern and northern points within Nares Strait when big blocks of sea ice try to flow through the strait’s restricted confines, become stuck and are compressed by other ice. This grinds the flow of sea ice to a halt.
“We don’t completely understand the conditions conducive to the formation of these arches,” Kwok said. “We do know that they are temperature-dependent because they only form in winter. So there’s concern that if climate warms, the arches could stop forming.”
To quantify the impact of ice arches on Arctic Ocean ice cover, the team tracked ice motion evident in the 13-year span of satellite radar images. They calculated the area of ice passing through an imaginary line, or “gate,” at the entrance to Nares Strait. Then they incorporated ice thickness data from NASA’s ICESat to estimate the volume lost through Nares.
They found that in 2007, Nares Strait drained the Arctic Ocean of 88,060 square kilometers (34,000 square miles) of sea ice, or a volume of 60 cubic miles. The amount was more than twice the average amount lost through Nares each year between 1997 and 2009.
The ice lost through Nares Strait was some of the thickest and oldest in the Arctic Ocean.
“If indeed these arches are less likely to form in the future, we have to account for the annual ice loss through this narrow passage. Potentially, this could lead to an even more rapid decline in the summer ice extent of the Arctic Ocean,” Kwok said.
For more information about NASA and agency programs, visit: http://www.nasa.gov .
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h/t to Dr. Leif Svalgaard
If the ice in the floe was very old and very thick as stated, and if this is a new circumstance, then perhaps thick old ice doesn’t compact to form arches as does ice normally found there, or perhaps it had sufficient wind driven energy to break up or prevent arches from forming. I don’t see though how ice moving around in subfreezing temperatures can be evidence of global warming. For that to happen you need energy, and at that time of year the lights are out up there.
Perhaps Robert should blame George Bush for this one as warming clearly is not a probability in the dead of arctic winter.
Should these Marc Morano videos appear on the front page of WUWT some time soon?
ClimateDepot’s Morano: Global Warming Already Dead, ClimateGate ‘Withheld Embalming Fluid’
http://www.businessandmedia.org/articles/2010/20100219103457.aspx
Darn it. Amino beat me to the death spiral reference. Has anybody coined Ice Gate-gate yet?
RE: mikelorrey (22:36:11) : “Please cite a peer reviewed, data transparent study not published by the Hockey Team, an advocacy group, or funded by an advocacy group (and I regard the UNIPCC and US and British government agencies to be advocacy groups) which actually makes these predictions….”
My statement was an observation of what I believe others may be thinking based on my general impression of comments I have seen elsewhere…
In any case, invading Canada has been bad luck for the US. ~ Evan>
I have decided to call off the pre-emptive strike against Russia. They have almost 800,000 people in uniform, and we have only 30,000. For starters, we barely have enough barracks for our own soldiers, what are we going to do with 800,000 prisoners of war? Second, I’d need to dedicate 29,996 to gaurd duty which would leave only 4 to deal with the whole Denmark thing.
[Reply – Probably prudent not to get involved in a two-front war. ~ Evan]
These arches form in winter. The winter of 2006-2007 saw more ice than the winter of 2005-2006 did. Spring and Summer 2007 air temperatures were below average. There is nothing to indicate that the lack of ice arch formation was temperature related. It has not happened since and arctic ice is recovering. The 2007 ablation season started with more ice than the 2006 ablation season did. Old ice has been accumulating since 2007.
So far it would seem that 2007 was some sort of fluke and it probably happens from time to time.
My guess is that 2010 will be close to 2006 at minimum.
George E Smith:
Since salt water of more than 2.47% salinity has a positive temperature coefficient of expansion down to the freezing point, then the sea water must shrink, so the level goes down. If the temperature coefficient was constant with temperature (it isn’t), then the sea level fall, is independent of how much water cools how much>
Not certain I followed that. The amount of water a floating block of ice displaces is equal to the mass of the ice. As the ice melts it becomes water of the same temperature as that it was floating in, so the amount of water displaced by the “melted ice” should equal the amount of water displaced by the actual ice?
Spector (22:29:39) :
Another issue is predicted rise of sea-level if all the Greenland ice melts and the even more catastrophic rise if some or all of the ground supported Antarctic ice also melts.
Given that the mass balance relationship between increased melting and increased precipitation in Greenland is so little understood, I’d say it’s even money whether the Greenland ice sheet would grow or shrink with all that open water available to fuel snowfall. Check out the lake effects snow records for Buffalo.
rbateman, are you sure that you have the date for the ice free sub picture right? March 17th?????????
Speaking of sea level, anyone have any idea of how often ucolorado updates this:
http://sealevel.colorado.edu/results.php
It hasn’t been updated since some time in 2009.
Like just about everything to do about climate change , it is nearly all about natural cycles and/or events over which we have absolutely no control.
This is just another case of point in that we do not yet really understand more than a very few of the many factors which affect climate. We are fundamentally ignorant about a hugely complex problem, parts of which can be described as ‘chaos theory’.
Rising carbon dioxide levels may or may not play a minor role in the recent small increase in the Earth’s temperature, but this temperature increase is no different from what has been experienced thousands of times previously in the geological past.
For the alarmists, the Arctic ice melt in 2007 was incontrovertible ‘proof’ of AGW. Now that the Arctic ice extent is back to more normal levels – and in a El Nino year! – the alarmists say nothing.
One thing is 100% guaranteed: you will not be reading about these findings in Real Climate or Al Gore’s website.
Tom P (17:50:56) :
“If indeed these arches are less likely to form in the future, we have to account for the annual ice loss through this narrow passage. Potentially, this could lead to an even more rapid decline in the summer ice extent of the Arctic Ocean,”
Tipping point?
As my mother used to say If Ifs and ands were pots and pans there’d be no need for tinkers.
sagi (19:10:20) :
Any evidence that suggests that ice breaker activity should, by the precautionary principle, be prohibited in the sensitive area north of the Nares Strait?
Makes sense, it’s the Artic equivalent of burning rainforest.
mikelorrey (22:36:11) :
“Please cite a peer reviewed, data transparent study not published by the Hockey Team, an advocacy group, or funded by an advocacy group (and I regard the UNIPCC and US and British government agencies to be advocacy groups) which actually makes these predictions….”
I wouldn’t trust the a study from the CSIRO (Australia), either. It seems they have received instructions from Ms Wrong (mis-spelling intentional)
we need to geoengineer ice arches, obviously
George E. Smith (22:46:09) :
“Since salt water of more than 2.47% salinity has a positive temperature coefficient of expansion down to the freezing point, then the sea water must shrink, so the level goes down.”
Even small changes in the sea water density have an effect on the ocean currents, effect of which can be much larger than expected in the critical areas such as the Labrador Sea.
“Labrador Sea currents tightly govern the strength of the Subpolar gyre’s circulation, which is the engine of the heat transport across the North Atlantic Ocean.”
http://hal.archives-ouvertes.fr/docs/00/41/83/04/PDF/NATA.pdf
George E. Smith (22:46:09) :
“Since salt water of more than 2.47% salinity has a positive temperature coefficient of expansion down to the freezing point, then the sea water must shrink, so the level goes down.”
Even small changes in the sea water density have an effect on the ocean currents, effect of which can be much larger than expected in the critical areas such as Labrador Sea.
“Labrador Sea currents tightly govern the strength of the Subpolar gyre’s circulation, which is the engine of the heat transport across the North Atlantic Ocean.”
http://hal.archives-ouvertes.fr/docs/00/41/83/04/PDF/NATA.pdf
“Kwok and colleagues….”
hmmmmm …. kwik ,kwok and colleagues ?
Historically ice loss in the Arctic is nothing new,
Less Ice In Arctic Ocean 6000-7000 Years Ago (Geological Survey of Norway)
If you have an hour or so, this is well worth it:
Colloquium on The Peculiar Issue of Global Warming
Spreaker: Dr. Richard Lindzen
Hosted at Fermilab:
http://vmsstreamer1.fnal.gov/VMS_Site_03/Lectures/Colloquium/100210Lindzen/index.htm#
davidmhoffer (23:18:27) :
“‘the “melted ice” should equal the amount of water displaced by the actual ice?”
I am not sure about that.
Since the ice contains significantly less salt then the water it is in the ice actually displaces slightly less volume of salt water then the mass equivalent of the fresh water (which is the ice). When it melts, the fresh water combined with the existing salt water, would occupy less volume overall once the salt levels were equalized, since the volume or water has not changed but the density of the salt has diminished.
If you pour a less dense liquid into a more dense liquid the combined volume is less the sum of the two original volumes.
Would this mean that the sea level would actually drop slightly if all the ice melts in the Arctic Ocean?
If so the addition melt water from Greenland could possibly bring it back up to the original level.
Or have I missed something?
We have known for many hundreds of years of the effect that warm currents and winds have on arctic ice. Each generation seems keen on reinventing the wheel, or in the warmists case trying to pretend there was never a wheel in the first place.
All the following references come from my article carried here last year. It demonstates the innumerable records and wealth of documentation collected from the time of the Huidson Bay co in the 1600’s, whalers, sealers, through to scientific expeditions held in the 1820’s to determine the reasons for the arctic ice melting at that time.
http://wattsupwiththat.com/2009/06/20/historic-variation-in-arctic-ice/#more-8688
“The uncharted coastline of east Greenland became clear of ice around 1820, and in 1822 Scoresby, in the midst of an arduous whaling voyage, sailed along some 400 miles of this inhospitable landscape, charting it, and naming point as he went in honour of scientific and other friends, chief of which was Scoresby Sound, named for his father. Almost all his place names survive today.”
That Scoresby junior was a man to be believed when he claimed that the arctic was melting can be further seen here in this extract;
“Carrying on with great success the most demanding and arduous of all maritime activities -the hunting and capture of whales – he yet collected over a period of some 15 years data on sea currents and temperatures, ice formation and movement, wind directions and velocities, magnetic variations, marine organisms, biology of whales, structure of snow crystals and much besides, gathering all this original work in the historic-volume classic Account of the Arctic Regions. The publication of this work in 1820 marks the beginning of the scientific study of the polar regions.”
There are various interesting observations made by whalers in this book concerning the Arctic conditions;
http://books.google.co.uk/books?id=6dWY-gZTGLgC&pg=RA1-PA284&lpg=RA1-PA284&dq=ice+islands+1810+newfoundland+seal+fisheries&source=bl&ots=0CxEu02Mpq&sig=67q3SluOy-OIv4-3cO5vpgTmHag&hl=en&ei=R-UuSvrqLszLjAff4cmVCw&sa=X&oi=book_result&ct=result&resnum=6#PRA1-PA291,M1
“ice could whirl about as if in a whirlpool”: ‘soft ice’ in February
‘the large fields of ice which drift southwards in March and April from the polar sea’: ‘Great stretches of open water.’
Nansens detailed records on currents/wind
http://nsidc.org/data/docs/noaa/g02120_fram_hydro/
Within the article are further numerous measurements carried out by brave men who risked their lives to gatrher information that could be used as a direct record of the conditions at the time. They recorded wind directions/velocity, current strength and warmth at the surface and below, disappearing glaciers, and a whole host of other data. They may as well not have bothered.
Do ANY of our modern high profile climate researchers bother to read any history of the subject or do they want to rely on computer models?
Tonyb
http://nsidc.org/images/arcticseaicenews/20100203_Figure3.png
Seems the pole is a very windy place this past thirty years.
looks like one big centrifuge to me!
@crosspatch, look to http://www.climate4you.com/, section Oceans and scroll to the bottom.
Actually, 2007 was a peak of OHC and SST In the Arctic, so no wonder that those blocking ice formations were not there.