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
Poptech (05:25:56) :
Why is anybody using Real Player?
I perfectly agree. Took me ten minutes just to get it to play. But, It’s Femilab and gov’t up-to-date computer systems is not usually there. But the words are great. Just ignore the hangs in the video (don’t try, those pauses in the video portion ill not go away, I tried)!
Robert (10:39:35) :
@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.
…
I would say that meets the definition of “bad.”
————–
Reply:
You’re grasping at straws, Robert. Truly grasping.
Of all the reasons for the P/T extinction event, I’d say the least tenable is global warming because, as they project in your refrences, it “caused changes in oceanic currents.”
How about considering the splitting of the supercontinent (Pangaea) to FORM the Atlantic at that time as a much bigger driver of changes in oceanic currents? Heck, before the Atlantic existed there weren’t even any ocean currents IN the Atlantic! Certainly that would be a bigger factor than whether sea water was another degree or two warmer.
There are much better mechanisms for driving extinction events (large and small) and much better geologic evidence such as impact events (the Gulf of Mexico astroblem for this extinction, among other astroblems), volcanism (plate tectonics was going stronger back then than it is now), and even methane hydrate gassification, kicked off by a very large lava flow into the ocean.
But “global warming”? Each of the above more plausible explanations would have warmed things up and it was perhaps a component, but it wasn’t the heat that brough down the asteroids from heaven nor did it speed up separation of the plates. And it certainly didn’t melt the lava flow that warmed up the methane hydrates to volatility.
It could likely have been a combination of all three events (it apparently didn’t happen overnight), although the Big-5 Extinctions are just about as bad as this one.
No, it is doubtful “global warming” was the causitive factor, and didn’t trigger the tipping point for the P/T extinction event. If by “proximate cause” you mean the earth warmed up from volcanism/impact/lava flows that is indeed a likely outcome, but it wasn’t the predominant reason by any means in my humble professional opinion. Just like CO2 now being a “proximate cause” of current warming with a contribution of perhaps 3-5% of the total.
Of course, “global warming” is being blamed for everything now:
http://www.spiked-online.com/index.php?/site/article/2045/
http://blog.heritage.org/2008/10/07/blame-global-warming/
http://www.akdart.com/warming14.html
http://newsbusters.org/blogs/noel-sheppard/2008/08/04/wapo-stop-blaming-everything-global-warming
http://www.alphecca.com/?p=492
http://disinter.wordpress.com/2010/02/17/global-warming-to-blame-for-everything/
http://www.philvalentine.com/GlobalWarming.htm
(There are ~1,160,000 more references but I’ll let you find and digest them all)
D. King (11:38:37) :
D. King (11:59:33) :
Thanks. On first view I didn’t realize the ice being addressed was the medium grey and smooth portion in the photos, not the white. Your addition makes it perfect clear, basically a river of ice.
Well the Nares straight arches or bridges really collapsed in 2009, so much so that it was noted in MODIS images by the Canadian ice service. Yet 2009 summer minimum was higher than 2007. This shows ice flow out of the Nares straight has minimum amount of impact on the amount of melt on the Siberian side, where most of this is happening.
The massive melt in 2007 was down to wind patterns, but it was warm winds from Siberia melting it in situe and pushing it together, as well as clear sunny warm days.
Andy
Don Shaw, I agree with your last point. I have been stranded in the arctic while on a canoe trip waiting for the ice in a large lake to clear (days 20 to 23 of 60). Despite 80+ degree days we had to wait three days until a strong NW wind cleared the ice by pushing it onto the shore of the island we were marooned on (amazing to watch the slow but steady push of slabs, some 3 feet thick, sliding onto the beach). Below the treeline, the warm temps had sped up the melting—all the lakes we had traversed up to that point in the trees were clear of ice—but with no trees on the shore to trap and hold the warmer air, it’s wind alone that clears the lakes north of 60.
Leo G (23:36:10) :
Why not? Search the NYT years 1938/39.
The Soviet icebreaker Syedoff wasn’t frozen in @ur momisugly 85ºN until Dec 18th 1938 & was free again in Feb of ’39. Reporter Harold Denny.
Sorry, can’t remember the day in Feb ’39 it was freed but recall it as mid Feb.
Some alarmists questioned the article & made pointed comments about the reporters name being a thinly veiled bastardisation of denier. Many people corrected them.
The report here was on Dec 12th in an on this day story.
DaveE.
davidmhoffer to Robert: Oh SNAP! Nice one. Mind if I borrow it?
“You’re grasping at straws, Robert. Truly grasping.”
Yeah, I think not. In fact you posit warming as a likely cause of the extinctions, but attribute it to “lava flows/volcanism/impact” (talk about grasping at straws!)
I can only suggest you read what the paleoclimatologists have to say on the subject. The real scientists paint a very different picture of the Permian–Triassic extinction event than your wishful thinking here.
[snip – I’m tired of these baseless claims that somehow all skeptics are in the employ of oil companies, I’m certainly not. Nobody with skeptical views that I know is. Since you have nothing to offer but innuendo from the comfort of relative anonymity, while I and other skeptics put our names to our words, I kindly suggest you shut the hell up. – Anthony]
@ur momisugly DirkH (13:58:27) :
It’s a complaint about terminology. People know what an ice age is, and know we are not in one. We freely talk here about how we are overdue and will eventually enter a new one. Yes, we are in an ice age epoch, but that is freely understood as a long period of ice ages. So what point is there in saying we are technically still in an “ice age”, other than to attempt to convey a sense of some sort of “smarter-than-thou” smug scientific superiority?
Robert (13:51:42) :
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.
You may may finally have arrived at something we can both agree on. I have been digging through the pile of sludge that is “climate science” trying to find nuggets of truth since long before this or any other blog existed. I began as a skeptic and remain so because throughout that search the uncertainties have been mostly ignored, and even when credited they’ve been vastly underestimated. This is present on both sides, but I’ve ended up spending more time than I can really afford on this site because people like Anthony, Lindzen, Spencer, Christy, MacIntyre, et al, have all at least demonstrated the humility to admit what they do not know.
In the end this quandary is essentially a problem of epistemology. How does a rational person choose to believe what he chooses to believe, know what he thinks he knows? Way back in my formative years I was exposed to the works of Michael Polanyi. Until I recently spent some time thinking about these questions, I hadn’t really credited what a profound effect that exposure had on my mental outlook. I still think his books “Personal Knowledge” and “Meaning” are the best explorations of the topic I’ve ever encountered and would recommend them highly to anyone looking to learn how their own mind really works.
Ice jams would form (and yes I have seen them) at different part of the narrow depending on the current and wind present at the time of the formation. Therefore it would still be unique in that some areas would lead to a more robust jam (IE longer lasting) than at other times. I stand by my statement. It should be rather highly variable each time it forms. Which is different from a flat shelf bridge.
Don Shaw (14:38:02) :
Good points. Keep in mind that the DMI temperature chart covers only the area above 80 degrees North, but the ice can extend as far south as the 60th parallel, so I probably spoke up too quickly earlier: the air temperatures at the edge of the ice might well be different. In a sensem you are asking if the DMI product might not be a good “proxy” for the entire ice area. I’d suggest that the increase and decrease in ice extent are the results of “local” conditions that have little if any effect above the 80th. It might be more to the point to determine where the changes in extent are occuring and check the temperature, wind and current conditions for that area…. and ice-breaker activity, as well, if Mike Odin’s suggestion earlier is really valid.
Now, having climbed out on this branch, some one with more familiarity with this might want to chime in… but don’t hand me a chain-saw please!
[snip – I’m tired of these baseless claims that somehow all skeptics are in the employ of oil companies, I’m certainly not. >
Mods permitting….
Some time ago I posted my artificial intelligence simulation of the information exchange between a physicist and an IPCC climatologist. Despite repeated end state corruption in the simulation, it was well recieved. I’ve now taken the extra step and simulated an information exchange between an IPCC Climatologist and Big Oil. Big Oil turned out to be hard to simulate as an average, and I had to break it up into several simulations by geographical range. A bit long to post here (but happy to if asked) so here’s the link. Sorry, but that end state corruption loop showed up again. Don’t get mad…. just laugh
http://knowledgedrift.wordpress.com/2010/02/09/the-oil-tycoons-and-the-climatologist-follow-the-money/
Robert,
Thanks for you comments, they have given some insight into the factors contributing to ice extent growth and melting.
I guess I look at the extent plot too much, it is like watching paint dry.
Daniel H (05:56:06) :
I am aware of realplayer alternative that is not the point. I haven’t had to use anything but Flash in years and have no plans on changing that.
Susan C. (12:40:42) :
I will take the Norwegian Geological Survey as more than just “anecdotal”,
Less Ice In Arctic Ocean 6000-7000 Years Ago (Norwegian Geological Survey)
And they have presented a paper,
Driftwood and ice – a sketchy history of Holocene multiyear sea ice in the Arctic Ocean
(Arctic Palaeoclimate and its Extremes (APEX), pp. 27-28, 2009)
– Svend Funder, Kurt H. Kjær, Hans Linderson, Astrid Lyså, Jesper Olsen
To–
Robert E. Phelan (09:58:14) :
I have no doubts that the icebreakers contribute
to the demise of the ice arches–
that is the icebreaker function–
to keep waters navigable–and ice arches impede navigation.
http://www.canadiangeographic.ca/magazine/ma06/indepth/people.asp
“Well, we break through it, yes. In areas like Peel Sound,
where you would find those three types of ice, the ship has been
tasked to go through and break for a variety of different reasons.
In 1999, we were in a really tough area where in about 24-hours
the vessel made about 5.6 kilometres. It took us a couple of days
to get through a ridge that was very hard. We had all five engines
online and we burned about 100 tonnes of fuel. We can’t do
that for an extended period.”
Peel Sound–a couple of days to
get through an ice ridge–
Perhaps Mother Nature would
have taken quite a bit longer to get
through that ridge unassisted and possibly
no ice flushing would have occurred at all
that year or in subsequent years–
the captain of this icebreaker certainly
did not think the ridge would clear
without his assistance.
It certainly indicates that there was less ice in the 1940’s
when easy transits were made with leaky scows
and no navigational satellites mapping ice.
It does not now sound like rotten ice
to me–
but maybe after 10 years of yearly smashing by icebreakers
the ice ridges in Peel Sound and elsewhere
now no longer form very robust ice arches.
Likewise it must be assumed that Canada ice breakers
have been and are tasked with
clearing ice ridges in Nares Strait and elsewhere–
after all, keeping these passages navigable
is the assignment of the icebreakers–
And ice flushing is just an AGW perk.
The icebreakers return South in the Fall
and head north in the spring–
http://www.cbc.ca/canada/north/story/2009/08/27/arctic-icebreakers.html
And the returning icebreakers
bring with them the little red dots
(indicators of sliced ice) which begin
to proliferate from March to May
every year in the Labrador sea and
migrating to Hudson’s Bay–
the red dots form straight lines or smooth
geometric curves(nature abhors smooth or straight lines)
and invariably slice off large
(thousands of square kilometres) hunks
of sea ice.
I have observed this process repeat
in March April and May
over the past 2 years–
http://polar.ncep.noaa.gov/seaice/hires/global.xml
and by making daily observtions of the labrador Sea
Hudson’s Bay area, it soon becomes obvious that no other
factor can account
for straight or curved red dotted lines
repeatedly and almost daily appearing–
which occur nowhere else
(except at some Russian icebreaker areas)
and which result in large sheets of sea ice separating out along
those red dotted lines
and then drifting off into the Gulf Stream remnants.
So you too can observe this process by watching
the above link daily (unless you trust the archives)–
or if you find daily observation of detail boring
you might choose to examine
some of the March -May archives-
Here are a couple of animations that might interest you-
Unfortunately they cannot be slowed or enlarged.
http://polar.ncep.noaa.gov/seaice/analysis/animation/nanim.200903.gif
http://polar.ncep.noaa.gov/seaice/analysis/animation/nanim.200902.gif
http://polar.ncep.noaa.gov/seaice/analysis/animation/nanim.200904.gif
Robert (15:48:13) :
[snip – I’m tired of these baseless claims that somehow all skeptics are in the employ of oil companies, I’m certainly not. Nobody with skeptical views that I know is. Since you have nothing to offer but innuendo from the comfort of relative anonymity, while I and other skeptics put our names to our words, I kindly suggest you shut the hell up. – Anthony]
I was at the gas station the other day and they gave me a coupon for 4 cents off a gallon, does that count?
The Siberian Traps volcanic events (the largest volcanic events known about) likely caused the Permian extinction.
The latest paper (by all the experts on the event) resolving the timelines and the extent of the volcanism place it starting just before the Permian extinction with enough impact to cause the extinction (over 5 million km2 (65% of the size of the continental US) were covered by magma up to 3.5 kms deep).
http://www.le.ac.uk/gl/ads/SiberianTraps/PDF%20Files/Reichow%20et%20al.%202009.pdf
The isotope data covering the timeline has high enough resolution to indicate there was a sharp down-spike in temperatures at the time, 5C or so, versus a global warming event as asserted by the pro-AGW set.
Poptech (17:13:36)
Thanks for that reference, I hadn’t seen it.
But a conference presentation is not a peer-reviewed paper, where one can assess the data and methods to determine if the results are plausible. I would need to see that level of detail before I was convinced. A printed abstract is not the same thing at all.
I’ll continue to look because I would like to know what they did.
Don Shaw (17:07:19) :
Yeah, I look at the DMI, IJIS and Arctic Roos charts everyday, too and often wonder just what it all means. It’s been a bit snowier here in Southern New England but the temperatures haven’t really been that much to complain about and Long Island Sound has yet to freeze over.
Mike Odin (17:18:05) :
Interesting stuff. It looks like you’ve been doing your homework. It would be fascinating to see hard figures for how much of the ice is actually broken each year and how it affects the charts published by IJIS and the others…. a kind of “…this is what the extent would be like without our efforts…” using arctic sea-ice coverage as a measure of the effects of global warming would be, as you’ve been pointing out, rendered invalid and useless by our efforts to eliminate that ice. Since it is the job of the CCGS to eliminate ice, I’m sure there must be a nice series of reports somewhere detailing just how successful they are in doing their jobs.
Susan C. (19:29:31) :
There have been other papers on this,
Holocene sea-ice variations in Greenland: onshore evidence
(The Holocene, Volume 14, Number 4, pp. 607-613, 2004)
– Ole Bennike
Just because a paper is peer-reviewed does not mean the data and full methodology is available. All peer-reviewed means is an journal editor’s hand picked reviewers signed off on the paper.
“Robert (22:32:54) :
Arctic ice area (summer, 1979-2000 average): about 7 million sq km (1.4% of the earth’s area)”
And another thing, what you describe is sea ice extent ie defined “as the areal sum of sea ice covering the ocean (sea ice + open ocean)” where sea ice is over 15% by area.
see http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
So area of actual ice is going to be well below 7 million sq km. Who knows they may use extent as the measure because it creates bigger numbers to frighten people with.
There is some good stuff here about ice movement, relating back to claims of massive losses from submarine data:
http://ipo.npolar.no/newsletters/archive/ice_climate_2001_09_no_01.pdf
Is Arctic Sea Ice Rapidly Thinning? Greg Holloway and Tessa Sou. Institute of Ocean Sciences, Sidney BC, Canada
Also in the same edition: Fram Strait Ice Fluxes and Atmospheric Circulation
1950-2000 Torgny Vinje, Norwegian Polar Institute
Mike Odin (04:17:53) :
“I believe they do this to reduce the sea ice area
(to promote Canada’s AGW agenda) and also to enhance
the flushing effects of currents to clear the
northwest passage earlier and more easily and
thereby to continue to trumpet that canard.
Although this sea ice is probably less than 0.5 meter
in thickness, the continuous repetition of
the icebreakers deliberately slicing it will probably result in
the overall removal of at least 500 thousand
square kilometers of ice over the next few months–
thereby skewing ice measurements and
NW passage opening possibilities–
and has done so for at least the past 2 years–”
Thanks, Mike, for a useful and interesting post. There are massive benefits to USA, Canada, Russia and other countries bordering the Arctic if it became ice free. I’ve seen estimates that 25% of the worlds oil lies under the Arctic, so all these countries have a vested interest in ‘encouraging’ the ice to leave. The following article is interesting, as it indicates a rapid growth of ice-breakers.
Polar Icebreakers in a Changing World
“Commercial vessel transits typically encompass cargo vessels transiting either the Northern Sea Route (above Russia) or the Northwest Passage (above Canada) or the delivery of supplies to Arctic destinations along either of those routes. In 2004, $4.5 billion dollars worth of orders were placed for the construction of ice class tankers. Additionally, the ice class tanker fleet will grow by 18 million deadweight tons (dwt) by 2008; 262 ice class ships are presently in service and another 234 are on order (ABS, 2005).”
Full document on this site:-
http://www.nap.edu/openbook.php?record_id=11753&page=31