10/31 NEWS: See updated graphs here
UPDATED: 10/22/08 The new images below are even closer
Watching arctic sea ice rebound this year has been exciting, more so since a few predictions and expeditions predicated on a record low sea ice this past summer failed miserably. I’ve spent a lot of time this month looking at the graph of sea ice extent from the IARC-JAXA website, which plots satellite derived sea-ice extent. However, there is another website that also plots the same satellite derived data, the Nansen Environmental and Remote Sensing Center of Bergen Norway, and they have an added bonus: a standard deviation shaded area. For those that don’t know what standard deviation is, here is a brief explanation from Wiki
…standard deviation remains the most common measure of statistical dispersion, measuring how widely spread the values in a data set are. If many data points are close to the mean, then the standard deviation is small; if many data points are far from the mean, then the standard deviation is large. If all data values are equal, then the standard deviation is zero.
In a nutshell, you could say that any data point that falls within the standard deviation area would be considered “within normal variances” for the data set. That said, current sea ice extent and area data endpoints (red line) are both approaching the edge of the standard deviation (gray shading) for both data sets. Here is sea ice area:
Click for a larger image
And here is sea ice extent:
Click for a larger image
Extent has a bit further to go than area, and of course it is possible that the slope will flatten and it may not reach the SD gray area. It’s also possible it may continue on the current trend line. Only nature knows for certain. A complete presentation from Nansen is on this page which is well worth bookmarking.
What I find particularly interesting is the graph comparing the 2008, 2007, and 2006 sea ice extent. It appears 2008 extent has already bested 2006 extent:
with a hat tip to commenter Patrick Henry
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“Which leads me to wonder what the lower threshold of CO2 might be, beneath which life of any complexity on the surface of the earth would be impossible.”
“Actually it’s old CO2 being brought back into the system. Fossil fuels are all natural.”
“I understand that plant life would struggle severely at below 200ppm, and probably become extinct at levels at or below around half of present levels.”
In addition to fossil fuels (oil, natural gas and widespread beds of coal and peat) there are hundreds of metres of carbonate rock deposits covering vast areas of our planet – presumably all derived from naturally sequestered CO2. This natural sequestration continues in coral reefs today. Ultimately, is it correct to say that complex life on Earth will end when atmospheric CO2 falls below a certain level, due to natural CO2 sequestration? If yes, then is it not possible that the nasty, evil combustion of fossil fuels, as practiced by nasty evil industry, is the only significant factor that might help counteract this slow steady trend toward human oblivion?
Arctic Sea Ice melting in winter (getting thinner – so melting fom the bottom up due to water temperatures)
http://www.timesonline.co.uk/tol/news/environment/article5014744.ece
UK media still reporting Artic ice shrinking!
This whole article is reporting the state of Artic ice in 2007 and doesn’t mention the 2008 situation.
Times – London 26 Oct 2008 !
http://www.timesonline.co.uk/tol/news/environment/article5014744.ece
– Arctic is melting even in winter –
– The polar icecap is retreating and thinning at a record rate –
The Arctic icecap is now shrinking at record rates in the winter as well as summer, adding to evidence of disastrous melting near the North Pole, according to research by British scientists.
They have found that the widely reported summer shrinkage, which this year resulted in the opening of the Northwest Passage, is continuing in the winter months with the thickness of sea ice decreasing by a record 19% last winter.
Usually the Arctic icecap recedes in summer and then grows back in winter. These findings suggest the period in which the ice renews itself has become much shorter.
Dr Katharine Giles, who led the study and is based at the Centre for Polar Observation and Modelling at University College London (UCL), said the thickness of Arctic sea ice had shown a slow downward trend during the previous five winters but then accelerated.
She said: “After the summer 2007 record melting, the thickness of the winter ice also nose-dived. What is concerning is that sea ice is not just receding but it is also thinning.”
The cause of the thinning is, however, potentially even more alarming. Giles found that the winter air temperatures in 2007 were cold enough that they could not have been the cause.
This suggests some other, longer-term change, such as a rise in water temperature or a change in ocean circulation that has brought warmer water under the ice.
If confirmed, this could mean that the Arctic is likely to melt much faster than had been thought. Some researchers say that the summer icecap could vanish within a decade.
The research, reported in Geophysical Research Letters, showed that last winter the average thickness of sea ice over the whole Arctic was 26cm (10%) less than the average thickness of the previous five winters.
However, sea ice in the western Arctic lost about 49cm of thickness. This region saw the Northwest Passage become ice-free and open to shipping for the first time in 30 years during the summer of 2007.
The UCL researchers used satellites to measure sea-ice thickness from 2002 to 2008. Winter sea ice in the Arctic is about 8ft thick on average.
The team is the first to measure ice thickness throughout the winter, from October to March, over more than half of the Arctic, using the European Space Agency’s Envisat satellite.
Giles’s findings confirm the more detailed work of Peter Wadhams, professor of ocean physics at Cambridge University, who has undertaken six voyages under the icecap in Royal Navy nuclear submarines since 1976 and has gathered data from six more voyages.
The vessels use an upward-looking echo-sounder to measure the thickness of sea ice above the vessel. The data gathered can then be compared with previous years to find changes in thickness.
Wadhams published his first paper in 1990, showing that the Arctic ice had grown 15% thinner between 1976 and 1987.
In March 2007 he went under the Arctic again in HMS Tireless and found that the winter ice had been thinning even more quickly; it was now 50% of the 1976 thickness.
“This enormous ice retreat in the last two summers is the culmination of a thinning process that has been going on for decades, and now the ice is just collapsing,” Wadhams said.
The scale of the ice loss has also been shown by other satellite-based observations that are used to measure the area of the Arctic icecap as it grows and shrinks with the seasons.
In winter it normally reaches about 5.8m square miles before receding to about 2.7m square miles in summer.
In 2007, however, the sun shone for many more days than normal, raising water temperatures to 4.3C above the average. By September the Arctic icecap had lost an extra 1.1m square miles, equivalent to more than 12 times the area of Britain.
That reduced the area of summer ice to 1.6m square miles, 43% smaller than it was in 1979, when satellite observations began.
At the heart of the melting in the Arctic is a simple piece of science. Ice is white, so most of the sunlight hitting it is reflected back into space. When it melts, however, it leaves open ocean, which, being darker, absorbs light and so gets warmer. This helps to melt more ice. It also makes it harder for ice to form again in winter. The process accelerates until there is no more ice to melt.
Wadhams said: “This is one of the most serious problems the world has ever faced.”
If you thought that article was bad, the times also reports on more WWF hysterical gloom today……..
– Humans ‘drive biggest mass extinction since dinosaurs’ –
….Tony Juniper, environmental campaigner and former director of Friends of the Earth, said: “We are entering a mass extinction that is without precedent for a million years. ….
http://www.timesonline.co.uk/tol/news/environment/article5014714.ece
To be fair, the article doesn’t blame AGW.
Must be an oversight on their part.
Abortion is abortion guy. You can label it ‘forced’ or ‘choice’ but either way, it doesn’t matter because the end result is the same. It is authorization which is used in part to slow the growing size of the population. Simple enough?
Nice try, Rich. Saying that legal abortion, a right conferred by Roe V Wade is used to “slow the growing size of the population” here in the U.S. is absurd, and smacks of extremist right-wing paranoia.
If you remove authorized abortion, how much larger would our population be by 2070? How much faster would our resources dwindle without this mechanism?
First of all, making something which is now legal illegal would have disasterous consequences, most especially for poor and even middle class women (those who could afford to would simply go to Canada). It would be forced underground, and in situations where the health and life of the woman would be jeopardized. You, with your anti-abortion agenda obviously don’t care about that, though. The idea that our population would be larger without legalized abortion is a red herring, since it would still take place. Simple enough?
Warning: We are getting seriously off topic here. Let it go, please. – Dee Norris
Mary Hinge: “It was not a reference as such but just a pointer to look at the subject through more recent enlightened eyes rather than the older cataract ridden ones that still think that the MWP was a long lasting global event.”
You were there, then?
Mary Hinge (13:52:06) The problem isn’t in how you characterize your reference to Wikipedia, the problem is William Connolley, who makes a mockery of ‘distributed intelligence’ by his substitution of the ‘party line’ for the actual state of climate science. And your ‘more recent enlightened eyes’ provoked gales of ironic laughter and tears from my suddenly short-sighted eyes.
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Hmmm.
Dropped in at NSIDC for my Ice Extent fix.
Today is Oct. 26.
They’ve still got the Oct. 23 graph up.
Hey! What’s Up With That?
;0)
Peter (06:12:05) :
“You were there, then?”
You should forget about a career in sarcasm, you’ve got a long way to go before reaching the standard of adequacy!
Mary (08:03:12) So please reveal to our marvelling eyes the new enlightenment ‘getting rid of the MWP’. Surely you don’t mean Mann ’08, do you? If you do, see climateaudit.org for ritual auditing and ridicule of the paper.
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Agh! I choked on my toast!
From The Sunday TimesOctober 26, 2008
“Arctic is melting even in winter
The polar icecap is retreating and thinning at a record rate”
http://www.timesonline.co.uk/tol/news/environment/article5014744.ece
Mary
Still on about deconstructing the MWP I see.
Marks for persistence at least.
kim (11:54:04) :
http://www.agu.org/pubs/crossref/2002/2001GL014580.shtml
This is a study of New Zealand tree rings. I would urge you to download the whole article as the abstract shows pro MWP bias. The graph shows clearly two warm periods interrupted by a particularly cold period (the coldest period in the study) and other periods of near average temperatures. They also don’t mention the prolonged warm spell during the so called LIA. They also mention that that glaciers on Mount Cook underwant major expansion at the same time the vikings we colonising a small coastal strip of Greenland.
http://www-bprc.mps.ohio-state.edu/Icecore/Abstracts/Thompsonetal-climatic-change-2003.pdf
This is also very strong evidence and interestingly the data uses the same South American graphs that skepticsuse to ‘prove’ that the MWP was global. The 6 graphs (3 from south america, 3 from the Himalayas), when combined how a very similar profile o the Hockey Stick.
This strongly suggests that the MWP, rather than being a significant global event was much more likely to be an asynchronous series of anomolies.
Violently pulling this errant thread back on topic 🙂
Any further updates to the graph?
Cryosphere shows a visually remarkable gain in ice extent.
Mary Hinge (10:13:07) It seems apparent from discussion at Climateaudit.org that the science of paleoclimatology as interpreted through tree rings is inadequate. Those involved don’t know how to separate out the effects of temperature, moisture, injury, and nutrients. For instance, search through climateaudit.org for reports about Linah Ababneh’s thesis which contradicts Mann’s work desperately, and has been suppressed.
Please don’t refer us to Thompson’s work. He does not archive his data such that his work can be checked. Furthermore, when confronted with the fact that Gore misused his data in An Inconvenient Truth, he and his wife stated that they weren’t responsible for correcting it, when he is listed as an adviser on the film.
These people you trust, Mary, have lost credibility in the real world. It is only the echo-chambered insular climate science community that still believes that stuff.
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There’s another example, Mary, on the latest thread where you try to talk about the volume of ice in the Arctic and that the ice was surrounded by water. Look, this year represented an amazing turnaround and may represent the beginning of a freezing trend.
You should consider re-examining assumptions when you have to stretch to make points. If the globe is cooling long-term, as I believe, then your dissonance is only going to slowly increase. Recognize what is going on before you are too committed. Artificially encumbering carbon if the earth is entering a long and deep cooling phase will be a holocaust on the poor, and you should learn that before we get there.
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http://news.bbc.co.uk/1/hi/sci/tech/7692963.stm
/// The thickness of Arctic sea ice “plummeted” last winter, thinning by as much as 49 centimetres (1.6ft) in some regions, satellite data has revealed.
A study by UK researchers showed that the ice thickness had been fairly constant for the previous five winters.
The team from University College London added that the results provided the first definitive proof that the overall volume of Arctic ice was decreasing.
The findings have been published in the journal Geophysical Research Letters.
“The ice thickness was fairly constant for the five winters before this, but it plummeted in the winter after the 2007 minimum,” lead author Katherine Giles told BBC News. ///
back on topic, lol
we need an up date or better still add a new chart
dee or anthony
thank you for your efforts
kim (15:30:09) :
The writers of the article I cited were actually trying to show the MWP and LIA were global, they tried to word their abstract and conclusion to show this. If you read the paper you will see what I mean.
kim (17:37:29) :
“There’s another example, Mary, on the latest thread where you try to talk about the volume of ice in the Arctic and that the ice was surrounded by water. Look, this year represented an amazing turnaround and may represent the beginning of a freezing trend.”
Global warming models predict increased salinity in equatorial waters and decreased salinity in waters of higher latitudes. The decreases salinity means that water freezes at higher temperatures, this, coupled with the large melt means that a rapid initial refreeze was inevitable. You will notice now that the freeze is within ‘normal’ levels.
I wouldn’t take to much notice of Climateaudit. Steve McIntyre has more chips on his shoulder than a casino balance artist and his jeolosy of Mr Mann just oozes through his every pore!
REPLY: Mary I’m going to assume that you haven’t met Steve McIntyre in person. I have. Thus I’m going to tell you that your assessment is so far off base, the playing field you frequent is in another town. If McIntyre’s work was as you describe, it would be a simple matter for Mann to prove him wrong. Yet Mann has not been able to, taking the elitist tact of dismissing McIntyre’s work with a wave of the hand. If you’ve ever watched Mann speak, or read some of his writings, and then listen to McIntyre make a lecture or talk to him in person, you’d realize your mistake in categorization of personality. – Anthony
I previously commented on the vague/misleading definitions for ice extent/area on 23 Oct, Leon Brozyna (08:27:36) . It seems that those definitions at Nansen have now been expanded to avoid confusion:
Ice extent is the cumulative area of all polar grid cells of the Northern Hemisphere that have at least 15% sea ice concentration, using the NORSEX algorithm. Ice area is the sum of the grid cell areas multiplied by the ice concentration for all cells with ice concentrations of at least 15%. Ice extent and ice area are calculated for a grid resolution of 25 km. The difference between area and extent for our data is always positive. This difference represent the area of the open water in the pixels partly covered by ice (i.e. ice concentration less than 100%). In other words, ice area takes into account that there is a fraction of open water in pixels with ice concentration above 15 % and below 100 %”. Ice extent does not include this effect and gives therefore a higher number of square km than ice area.
Have to applaud their effort at clarification. The only nit I have to pick is in the last two sentences. It would be even clearer to say, instead:
In other words, ice area takes into account that there is a fraction of open water in pixels with ice concentration above 15 % and below 100 %”, and eliminates it. Ice extent does not include this elimination effect and gives therefore a higher number of square km than ice area.
See:
http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic
Mary Hinge (03:26:25) Why ignore my contention that the science of tree-ring paleoclimatology is inadequate for the task assumed? The failure of peer review in the field, and the paucity of effective statistics renders it so easily manipulable as to dismiss it out of hand as an unreliable path to the truth. I might add something about the integrity of some of the researchers but in the interest of civility, I’ll let this insinuation suffice.
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Hmmmm, I wonder why the “daily” graph ain’t???
I see that, as far as ice is concerned, the BBC is still in last winter!
http://news.bbc.co.uk/1/hi/sci/tech/default.stm
And they are still referencing last year’s record melt from their current article.
Well, that’s the BBC’s impartial and balanced reporting, I guess.
According to the BBC the Arctic ice is to thin?
http://news.bbc.co.uk/2/hi/science/nature/7692963.stm
Mike T (08:25:48) :
I see that, as far as ice is concerned, the BBC is still in last winter!
http://news.bbc.co.uk/1/hi/sci/tech/default.stm
And they are still referencing last year’s record melt from their current article.
Well, that’s the BBC’s impartial and balanced reporting, I guess.
Indeed, for them to comment on forthcoming publications they have to wait for them to be published or at least have the embargo lifted! The paper was written and submitted to Geophysical Research Letters and was accepted for publication this month. It’s customary to write papers on events after they happen and the publication process, review & proof-reading takes a while (~6months in GRL)!
KA Giles, SW Laxon and AL Ridout, ‘Circumpolar thinning of Arctic sea ice following the 2007 record ice extent minimum’, Geophysical Research Letters, doi: 10.1029/2008GL035710, in press (accepted 10 October 2008).
So Anthony, Howcum the red line shuts off as of the 22nd of October. Did their satellite crash and burn or has something serious happened.
We want to know the rest of the story.