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 .
========================
h/t to Dr. Leif Svalgaard
Rocky Road said: “There is no comparison. Warm is good; cold is bad!”
I would think that such blanket statements need to be put into boundaries. I am thankful there is a greenhouse effect going on right now on this planet. The water vapor, CO2, methane, and the other trace GH gases keep us at a nice moderately warm average global temperature. I wouldn’t want to be a whole lot warmer and I wouldn’t want to be a whole lot colder. The whole AGW issue comes down to this: Can human activity make this nice GH blanket we enjoy too thick, so that we do become a whole lot warmer too fast, like putting too many blankets on top of yourself on a cold winter night and waking up sweating. So fast that food crops, fresh water supplies, ocean fisheries, and the whole web of life can’t keep up and we see some mass species die-off.
But I digress…let’s get back to the issue of what “caused” the extreme summer ice melt of 2007. Was is just wind blowing ice out of the arctic through opened straits free from ice dams? Nope, nothing so simple of course. It was a combination of factors including warm water flowing into the region, high temperatures, high-pressure that lingered months at time, and older thicker ice being calved off and blown or drifting further south to melt. See this chart:
http://nsidc.org/news/press/2007_seaiceminimum/images/20070910_temperature.png
To see the very warm temps in the region during the summer. Now of course the question is, were these high-temps caused by AGW, or, were they part of some natural variation? I think the central issue for many seems to be a reluctance to believe that humans can impact the climate system in any meaningful way. And if the answer is yes, and second issue becomes this: We know that another glacial period would naturally be in the future and due any time for earth I(we are technically still in an “ice age”). So can human activity somehow mitigate these natural cooling that we’re due for? Skeptics remained unconvinced, and the so-called “warmists” say yes. I for one, knowing that the next advance of the glaciers is due any time, hope that we can warm the earth (by putting on that extra blanket) to mitigate or forestall the next advance of the glaciers….and wouldn’t it be ironic if a sudden and rapid cooling really did begin to appear and we we’re suddenly united in our efforts to figure out how to enhance the GW effect? Time will reveal all…
“R. de Haan (03:21:17) :
Antony, where is John Coleman’s latest film?
Have you already seen it?”
Go directly to kusi:
http://www.kusi.com/weather/colemanscorner/84515637.html
Oh, and by the way, global tropospheric surface temps are a full one degree warmer right now than this time last year:
http://discover.itsc.uah.edu/amsutemps/
There is already a huge amount of information and research done on the formation of ice jams in rivers. Their “ice arches” are simply a new name for an ice jam. The difference being it is in an open sea environment rather than a river. That would imply that they need to look at mechanics which are unique to the ocean (such at tides) and the fact it does not necessarily have a uniform current flow like a river does. Other than those considerations the mechanical process of ice jam formation should be very similar in the Nares Strait to what you would expect in a large river.
Critical elements involved in ice jam formation is the bulk quantity of ice flows at any given time, and the profile of the cross section where the jam tends to form. Ice jams form in areas where the river channel narrows (tending to push the ice together at the constriction point). Once the blocks of ice make contact a natural arch will form if the blocks do not yield to the upstream flow pressure.
I would suggest that the researchers that are investigating this, invite a few hundred folks that work with ice jams every year to take a look at the problem. There is already a great deal of experience and research in existance about how ice behaves under these narrowing channel conditions. No need to re-invent the wheel here.
They might start by talking to the folks at the Corps of Engineers and similar agencies that have been dealing with this sort of problem for the better part of a century in every nation in the world that has navigable waterways in subarctic climates.
There are several hydraulic issues unique to ice jam formation that an experienced ice jam engineer might bring to the investigation.
At the early stages of freeze up, the water begins to develop large quantities of frazil ice (slush) that gradually turns the water into a thick sludge. Combine this with slabs of surface ice floes and anchor ice buildups on the bottom of the channel.
(anchor ice freeze out of ice on the bottom of the channel as super cooled water is mixed down to the bottom of the channel by flow turbulence. Freezing on contact to surfaces. Gradually building up ice from the bottom of the channel)
Once these conditions combine the flow of ice slows and then jams together locking the ice into a solid barrier. The only stable form of that barrier would be in the shape of an arch.
http://www.hydrol-earth-syst-sci.net/12/1249/2008/hess-12-1249-2008.pdf
http://www.springerlink.com/content/wh0mg124pg05v257/
http://www.hydrol-earth-syst-sci-discuss.net/5/1021/2008/hessd-5-1021-2008-print.pdf
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V86-489448G-1&_user=10&_coverDate=07%2F31%2F2003&_rdoc=1&_fmt=high&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1214705449&_rerunOrigin=google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=660f4e54e9cfef968dff7a86f218a638
Larry
R. Gates (09:13:25) :
Rocky Road said: “There is no comparison. Warm is good; cold is bad!”
I would think that such blanket statements need to be put into boundaries. I am thankful there is a greenhouse effect going on right now on this planet. The water vapor, CO2, methane, and the other trace GH gases keep us at a nice moderately warm average global temperature. I wouldn’t want to be a whole lot warmer and I wouldn’t want to be a whole lot colder.
—————-
Reply:
What you want is irrelevant and unobtainable (with due respects).
First, I didn’t make a blanket statement such as “It will be warm forever”. As a geologist I can tell you earth’s climate change is far more intense than the vast majority of AGWers would have us believe (otherwise it quickly shoots down their hypothesis and renders their hysteria meaningless).
Simply look at the geological record to see what Mother Nature has provided; I’m absolutely convinced that what man can do TO the climate and what man can do to REGULATE the climate is 4 to 5 orders of magnitude LESS than the natural forces than control the climate. In other words, essentially meaningless in the grand scheme of things.
You or your kids or your kid’s kids (i.e., somewhere down the line) ARE going to see the next Ice Age. It’s a given and it ain’t gonna be pretty. It’s not as predictable as clockwork on our timescale, say within one generation or one lifetime, but it is inevitable. I’m too much of a believer in “the past predicts the future” and catastrophic uniformitarianism (or is it “uniform catastrophism”) to ever be convinced otherwise.
But like you say, time will reveal all.
It’s just not going to be a smooth ride forever. It only could be if man could control the earth’s thermometer, and that supposition is simply laughable.
I’m just glad we are (or is it were?) in a warming trend. If man’s contribution to CO2, which adds abundantly and beneficially to the biosphere, is in some small way helping that out, I’m all for it.
Bill Illis (06:15:16) :
It’s good to see you back. It’s been a while.
I always like your comments, animations, illustrations. Always interesting.
Mike Odin (04:17:53) :
Interesting idea. Do you have documentation other than the chart? There would have to a ton of documentation on the ships, their current locations and missions, metrics (miles of sea-lane opened, distance traveled, etc.) position papers, policies… (e.g. we are committed to keeping the Passage open 10 months of the year…) I did a quick check and was a bit surprised at how many icebreakers Arctic nations had and that there were a goodly number in private hands…. including Greenpeace (anyone know where the Arctic Sunrise is now? Inquiring minds and all that…)
Lopping a half-million square kilometers off the pack would rather bugger the metrics, don’t you think?
As a geologist, the main thing that bothers me with this whole AGW mantra is how counterintuitive it is. And the reason is because climate change is the modus operandi of the earth. The only constant about climate change is change. It gets warmer, and it gets colder; it is cyclical. And there are temperature cycles as short as a day and as long as 100 million years or more. There are cycles opon cycles upon cycles upon cycles.
To believe that somehow what man is contributing to GHGs will tip us over the edge is hardly convincing considering we’re seeing a small blip at the bottom of the CO2 curve, which has been 10 times higher in the past; certainly we’re not on a CO2 peak.
So we’re told we are facing hysterical warming yet the thumbscrews they want to apply destroy our ability to survive.
The recommended approach is to shut down any device, large or small, that puts CO2 into the atmosphere. There goes our ability to keep ourselves warm, fed, housed, clothed, transported, entertained, educated, proliferating, propagating and capitalized.
For some reason, they abandon proven alternatives like nuclear, hydro, and geothermal. Reliance on wind and solar is folly; they are unreliable. Don’t you dare say “drill, baby, drill”–you’ll be a candidate for the insane asylum.
It flat out doesn’t make sense; it does not compute; it is completely illogical.
Unless… Unless you consider some very scary alternative motives…
And stupidity is not a motive.
“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.”
But it isn’t back to normal. Not even close. Right now it’s down 700,000 km^2 from the 1979-2008 mean (http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png). Look at the trend. Arctic sea ice is disappearing much more rapidly than the models predicted.
Larry,
Thanks for the explanation!
I was curious at to any studies regarding causes for the arch to fail? Obviously sufficient warming would weaken it. But arches are notorious for being very strong one way, very weak the other. Would strong wave action for example, pushing against the inside of the arch fracture it and collapse it? Or strong wind for that matter? Neither seems likely with the amount of ice jammed up against the outside of the arch which would tend to stabilize it against anything but a really big force.
@Stefan: “The thing I get is, looking at longer periods, it is really hard to see how global warming could be bad”
Oh, I don’t know. Global warming is now thought to be the proximate cause of the Permian–Triassic extinction event, which wiped out 96% of marine species, 70% percent of terrestrial vertebrates, and was the only known mass extinction of insects. Fifty-seven percent of all families and 83% of all genera were killed.
http://en.wikipedia.org/wiki/Permian-Triassic_extinction_event
http://www.sciencedaily.com/releases/2009/12/091202205621.htm
http://www.sciencedaily.com/releases/2006/10/061021115722.htm
I would say that meets the definition of “bad.”
R. Gates (09:20:51) :
Oh, and by the way, global tropospheric surface temps are a full one degree warmer right now than this time last year:>
LOL. One channel, and degrees F and only one day on one year. Channel 10 is only 0.05 F and is no more meaningfull than just channel 5. Lets turn on all the channels for all the years:
13 – lower 1/3 of all years
12 – lower 1/3 of all years
11 – no data
10 – bottom of of all years
09 – lower 1/3 of all years
08 – top 1/3 of all years
07 – top 1/3 of all years
06 – middle of pack of all years
05 – top of pack of all years
04 – top of pack of all years
what to conclude from this? fluctuations exist and some things are getting warmer and some cooler.
Here is what they are talking about.
Here is the NASA GIF.
http://www.nasa.gov/images/content/427983main_earth20100218.gif
@ur momisugly R. Gates (09:13:25) :
Wait, now you are being confusing.
We know that another glacial period would naturally be in the future and due any time for earth I(we are technically still in an “ice age”).
We are still in an ice age? We have been told recently we have the hottest years “on record” and also often told they are the hottest “ever.” We likewise have the “hottest decade,” etc. It is so hot all the glaciers are melting, the Arctic will be ice free, even the Antarctic will melt, and we may well all drown!
All this heat and we still are not out of the last ice age? So when are we ever going to be out of the current one? Unprecedented high temperatures, all the fault of mankind, and still it is not enough to get us out of an ice age? How can this planet have ever gotten out of any ice age if this unprecedented warmth won’t do it?
Truly, this CAGW theory can be most difficult to follow. One may think it makes no sense at all!
Robert 10 24 53
Your link only goes back to sarellite records commencing in 1979. Try some of the books written in 1820 or Hudson Bay Co records going back to the 1600’s. They show enormous fluctuation in ice area to levels greater than and less than today. You can’t look at a 30 year chart and draw any meaningful conclusions.
This links to the first part of my post (TonyB 00:59:50) which leads to the various historic books. :
“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
Tonyb
Poptech (00:33:29, 20/02):
re: Historically ice loss in the Arctic is nothing new” with a link to a report on less ice 6000-7000 years ago. I noticed that report when it came out, which was based (as many of these are) on a press release (Oct. 2008). I have since periodically looked for a peer-reviewed paper describing this study but have not found one. I looked again today, same result. If anyone knows of an actual paper, it would be nice to know. Otherwise, as far as I am concerned, that report remains in the realm of anecdote.
However, this reference suggests no evidence for an ice-free winter (ie. complete loss of perennial ice) within the last 14 million yrs:
“Arctic perennial ice cover over the last 14 million years.” Dennis A. Darby. Paleoceanography, Vol. 23, PA1S07, doi:10.1029/2007PA001479, 2008.
Robert (10:24:53) :
” Arctic sea ice is disappearing much more rapidly than the models predicted.”
You seem to be missing one large and fairly obvious point. Whether the models are in error in a direction that supports or contradicts one’s point of view doesn’t prove anything, except that in almost all cases the models are wrong.
Being wrong in a direction we prefer is just as much a reason to ignore them as the opposite case.
“Being wrong in a direction we prefer is just as much a reason to ignore them as the opposite case.”
Here, here Dave! Why this is not obvious to the scientists involved is beyond me. Wrong is wrong.
Davidmhoffer: REPLY – The US won’t be invading Canada in any case. You’ve beaten us twice, so we’ve learned our lesson the hard way. ~ Evan]
“Wow, what version of history did you read? American history never mentions either incident and Canadian history…”
A funny little snippet from a fur trader’s journal (David Thompson) from 2 August 1812 when he was at Fort William about the taking of Michilimackinac Island:
At 2 pm, the Invincible arrived and passengers in her Messrs McGillis, Rocheblave, Jo Mcdonnel, Guideke, Simpson and Holmes &c. They bring the agreeable news that Mishelamakanac was taken the 17th July by Capt. Roberts, 40 regulars and 2-6 lb guns, aided by 260 Canadians under Messrs Crawford, Dixon and Potier [Porter], aided by about 450 Indians of different tribes. The place surrendered at discretion without firing a shot and the Indians we withheld from blood, but as they could not get the American scalps, they insisted upon having their hats.
“Dave Wendt (12:52:12) :
You seem to be missing one large and fairly obvious point. Whether the models are in error in a direction that supports or contradicts one’s point of view doesn’t prove anything, except that in almost all cases the models are wrong.
Being wrong in a direction we prefer is just as much a reason to ignore them as the opposite case.”
Scientific predictions are not like Biblical prophecy — absolute truth, or the lies of the devil. They are estimates, based on physics and math, and every input has an error bar, and every model — from climate science to Newtonian mechanics — has a limited ability to predict the real world, because the real world is always more complicated than the model.
Should we ignore the model because it doesn’t tell us everything and is sometimes off? I don’t know. Should we ignore a doctor who tells us our child’s fever is likely to go up to 103-104, and it goes to 106 instead? Should we refuse antibiotics because the doctor clearly doesn’t know what’s going to happen?
“kadaka (12:06:27) :
@ur momisugly R. Gates (09:13:25) :
Wait, now you are being confusing.
We know that another glacial period would naturally be in the future and due any time for earth I(we are technically still in an “ice age”).
We are still in an ice age? […]”
kadaka, you have to admit that in this case, R. Gates makes a lot of sense. We are in an interglacial period in an ice age epoche. It should also be pointed out that R. Gates has repeatedly stated that his objective is to “not believe propaganda from either side”, i paraphrase that from memory…
Should we ignore a doctor who tells us our child’s fever is likely to go up to 103-104, and it goes to 106 instead? Should we refuse antibiotics because the doctor clearly doesn’t know what’s going to happen?>
When the doctor tells me the kid’s fever is going up, I listen. When he starts telling me that the only cure is to buy antiobiotics from a drugstore that he owns, I start to get suspicious. When the kid’s fever starts to go down on its own before I even buy the antibiotics, I start to get even more suspicious. When he insists that HIS thermometer shows that the kids fever is still going up even though mine says it is going down, and then he refuses to even show me his thermometer to see for myself, and then one of his colleagues pipes up and tells me the doctor doesn’t even HAVE a thermometer, I get very very very suspicious. When he starts to tell me that the fever will cause my kid to spontaneously combust while the kid is running around healthy as a horse and has no fever at all…. and the doctor STILL wants me to spend huge amounts of money at HIS drugstore….
Yeah, I’m not listening to that doctor anymore.
Robert (10:24:53) :
” Arctic sea ice is disappearing much more rapidly than the models predicted.”
I doubt very much that models are modelling what happens to sea ice.That they breaks off, drifts, and then melts in warmer waters.
Robert E. Phelan (08:47:57) :
Don Shaw (04:54:27) :
“…It seems to me that the DMI temperatures that jog above and below the 42 year daily mean plot predict the jogs in the slope slope of the extent curve. This might make sense especially in the winter when wind and currents may have less impact…”
Good attempt, Don, but that little blue line near the top of the DMI chart represents the freezing point of water. The Jigs, Jags and jogs you currently see are at least 30 degrees Kelvin below that. At this time of year wind, currents and water temperature are the only explanations for sea ice extent. Air temperature, I’m afraid, has nothing to add.
Robert, appreciate your comments. Upon further reflection some questions/observations come to mind as follows
1) The DMI temperature plot shows the mean temperature above 80 degrees north parallel.
2) Most likely there is a temperature gradient between the 80th parallel and the north pole that on average the temperature is reduced as the measurement point is located further north.
3) I suspect that the temperature at the edge of the reported ice extent is above the currently reported mean of 245 K and is much closer to freezing which is 273.1 K than 245K.
4) What is the typical temperature at the edge of the extent?
5) The recent jogs around the mean temperature approach 13 degrees. I would be surprised if such a large temperature change would not affect the ice extent, but that is the essence of my question.
6) Surely other factors affect the freezing of the sea such as wind.
7) My observations from watching lagoons freeze over in the winter is that during a strong wind, the waves that form cause a mixing of the surface water with warmer water below the surface and prevent freezing. My experience is with mini waves and I expect the waves in the arctic could be huge and more dramatic. It seems to me that the freezing of the surface water in the lagoon starts overnight when the wind is less.
Additional comments considering the above appreciated.