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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“I think knowledge and truth are different concepts.”
, as St Thomas Aquinas saith. “Truth is the conformation of thought to a state-of-affairs.
Whoops! The Latin was apparently wrtten in disappearing pixels.
Veritas est adequatio rei intellectus.
What is usually reported as the standard value for ice extent is the 79-2000 average where the ice extent decreased only quite slowly. Why take the 79-2007 average instead?
Oh, yes, I see! So you can include the 2000-2007 years which are way below the 79-2000 average to make it look like it’s “going to normal again”, while actually it’s going back to the 2000-2007 average.
As a side comment: the models predit a strong melt in the summer, NOT in autumn or winter.
John Philip (01:05:25) :
But I bet the ‘ICE BACK TO NORMAL’ post is already written and waiting on the hard drive 😉
Anthony, in his infinitely patient style, will use the NSIDC newly mandated, politically correct terminology in his title:
“ICE BACK TO MEDIAN VALUE”
Re; PeteM
I think you missed my point.
I have no objection to comment from anyone. It is the comment being in the main bulk of the paper that I object to.
When reporting from an organisation like the WWF the DT made a decision to report it as a major story. There were obvious fallacies in the article about the extent of ice cover; ice free North Pole areas; etc. Yet they were left presented as fact.
These were left as a factual report, when it was obviously not factual.
As for Christopher Booker: he writes as an opinion, not as a news story. He appears on a separate page to news items.
He writes in the Sunday Telegraph not the DT.
What we seem to be seeing is a “tipping point”, tilting toward a new cooling climate regime. The beginning of new multi-year ice, with a vengeance.
Anyone planning on making the Northwest Passage next summer needs to reserve their icebreaker now, before they are all gone.
Patrick Henry: Great find. Thanks.
Flanagan: Oh, yes, I see! So you can include the 2000-2007 years which are way below the 79-2000 average to make it look like it’s “going to normal again”, while actually it’s going back to the 2000-2007 average.
So, by your logic then, the ice is actually heading into way below average territory. Wonder if the MSM will report that? Oh, wait, if it doesn’t support AGW alarmism, it isn’t news. Nevermind.
As recommended, I’ve bookmarked the Nansen page. In reading their explanation of ice area/extent, I can understand why some people may be confused as to the meaning of the two terms:
Ice Area is defined as the area covered by ice, excluding regions with 15% or lower ice concentration. Ice extent is defined as the area with a 15% or higher ice concentration.
On a quick reading, it almost sounds like the two are the same. They might do better to be more explicit, such as this:
Ice Area is defined as the total actual area of ice, in regions with 15% or higher ice concentration. Ice extent is defined as the total area, including water and ice, with a 15% or higher ice concentration.
So, if I look at 1 sq km with 50% ice concentration, then that’s 1sq km ice extent and ½ sq km ice area.
Caleb , Re Amundsen spending two winters at Goja Haven (1904 + 1905) I believe that the reason was choice, not unnavigable ice. i.e. Amundsens’ choice. His crew of 5 were apparently not best pleased, but Amundsen wanted to stay in order to learn about survival in the arctic and in particular the art of dog sledging. These skills were a large part of the reason for his success re the South Pole a few years later.
Regarding sea ice extent in the early 1800s there is some circumstantial evidence from the early British Navy expeditions. In 1819 Parry was the first to enter Lancaster Sound. He sailed West and reached 112.8 deg.W on 17th September. In the face of increasing ice (onset of winter) he turned back to a suitable winter harbour that he had spied earlier on the S. shore of Melville Is. where a few days later he dropped anchor – for the first time since departing London (!!) Although he had sailed a long way west in 1819, he found that the following season was very different and only escaped back East with some difficulty.
Ross was sent out in 1829 and sailed down the East side of Somerset Island and Bothia Peninsular hoping to find that the latter was an Island. It is not. After overwintering he set off back North the following summer – and made 4 miles (!) To cut a long story short, after 4 years (3 winters) in the ice and by dint of abandoning the 2 ships (which were too unwieldy in the heavy ice) they used the ships boats to escape North to Lancaster Sound where the survivors were found by whalers on August 25th 1832.
As I understand it the whalers in the 19th century who frequented Arctic waters every year, found that the seasons varied considerably. Conditions one year giving little indication of what to expect the next.
I don’t believe in dangerous AGW. I don’t believe the IPCC. I’m running out of people I DO believe in, especially with respect to so-called AGW.
However I have just gone to the trouble to look up, as suggested at the beginning of this thread, the graphs of the NERSC.
Whichever way you look at them, for a decade the trend line of both ice area and extent in the Arctic is negative. It would be very interesting to know the cause, and whether or not the overall trends is itself within a standard deviation of a longer term mean. It would also be very interesting to look at a more instructional period of time than 10 or 12 years. Anybody know where such could be found?
Then why do you keep posting about it and generating more comments?
RE: Arthur Glass (07:14:37)
Jeff Alberts (08:48:36) :
“Then why do you keep posting about it and generating more comments?”
If its considered important enough to be posted then why not? It’s just my opinion on this matter.
At the risk of going into CLimate Audit territory, the standard deviation as shown implicitly assumes that the data is IID. That is there is no relationship between last year’s ice extent and this year’s ice extent for exmple.
The implication is that the grey SD area (a type of random error band if you like) is actually much wider than indicated in the diagram.
John Philip says,
The Arctic Ocean is bounded on most sides by land. In a warming phase we would expect to see the summer extent decline while the winter maximum extent will also decline but much more slowly as the same fixed body of water freezes up – with some variation around the edges that are open to the sea.
According to the Telegraph pics your comment is total rubbish, there appears to be an abundance of water surrounding the ice in Sept 1979.
Try this link, ( http://www.socc.ca/seaice/seaice_future_e.cfm ) there appears to be plenty of sea here to, they model the present decline continuing to 2100, wow.
I would have thought that a 31% + increase in winter max for 2008 and rising was something to shout about. If the warming is global and still rising as you AGWers suggest, you should have surely seen a continuing decrease of ice extent similar to the decrease of the past few years. Warming what warming.
pablo an expat said in part…. about the Greening UK Daily Tegrelaugh……
“Why they pay Charles Clover for his stuff on green issues is beyond me.”
Could it be that they are so AGW fixated they had to employ someone with an appropriate name?
More Chilean Merlot!
Denis Hopkins
You are correct – Christopher Booker writes in the Sunday Telegraph .
And I agree that opinion sections are a valid part of a paper (if clearly positioned as opinion) – perhaps the issue is that the Sunday Telegraph needs to introduce a regular companion opinion section with ‘another set of views’ .. but that is a discussion for another place
Arthur Glass
“But humans have been running many ‘global experiments’ for at least ten thousand years, e.g. changing the lithosphere by clearing forests for agriculture … ”
I’d suggest your references to global experiments were infact mainly local, and it was possible to move on from the consequences to another location or continent (although a few civilizations did manage to wipe themselves out through spectacular stupidity).
Since we don’t have much long term research in the area of ‘change-the-atmoshpere-by-doubling-CO2-levels’ then effectively we’re gambling that the outcome .
John D-
Actually, the Cascade glaciers are no longer shrinking.
John D: Although this is anecdotal, there were no rain-on-snow events at Snoqualmie Pass near Seattle (elv 3100′) last winter. We experienced heavy snowfall and below freezing temperatures. We had great skiing until the end of May. Consequently, the near record snowfall was highly compressed and did not melt until mid-summer in shaded areas.
It’s hilarious how the AGWers are now saying this is “not a big deal” and “there is nothing to see here”, when just a month ago they were doing their best to drum up the SECOND LOWEST ICE EXTENT ON RECORD!!!
So that was a big deal (even though it represented a recovery from last year, more so than many experts, including the NSIDC, predicted), but now that October 2008 has seen a GREATER RATE OF GROWTH THAN ANY YEAR ON RECORD!!!, that isn’t a big deal. 2008 hit its low point earlier, began recovering sooner, and has gained ice at a remarkable rate – all signs that the Arctic is cooling down. Yet this doesn’t matter to AGWers, because it doesn’t fit the agenda.
Open your minds, people.
Looking at the graphs I have a question. They only plot this year and last wrt the mean ice w/standard deviation. Does anyone know when was the last time Arctic ice levels were within the ‘normal’ range?
Flanagan,
“What is usually reported as the standard value for ice extent is the 79-2000 average where the ice extent decreased only quite slowly. Why take the 79-2007 average instead?
Oh, yes, I see! So you can include the 2000-2007 years which are way below the 79-2000 average to make it look like it’s “going to normal again”, while actually it’s going back to the 2000-2007 average.”
Uhhhhhh…. I don’t think Norway is playing any games with the numbers. If anyone is playing games it is whoever leaves OUT part of the numbers…
Mike Bryant
If someone have the impression that NERSC somehow is less biased than say NOAA with respect to AGW, I think you are indeed mistaken.
In Norway we have three scientific centers dedicated to climate issues. two: NERSC, http://www.nersc.no/main/index2.php and the Polar institute (Tromsoe) http://npweb.npolar.no/english, working mainly on the scientific issues, and CICERO being a public outreach organization http://www.cicero.uio.no/home/index_e.aspx.
All three institutions are strog supporters of the dominateing AGW paradigm as propagated by IPCC.
They are fairly well funded and have recently brushed up their graphics interface, enabling nice and frequently updated presentations.
Another short quibble: Amundsen stayed in *Gjoa* harbor. Gjoa was the name of his vessels. The o is BTW the scandinavian letter ø (o with a slash) which is pronounced something between the u in ‘further* and e in “certain”.
Cassanders
In Cod we trust
having a baby is the most polluting act most individuals can do
Proof that greens want to see (other humans) removed from the planet. My question is, why don’t jaded adults dispense with themselves and make room for a happy, innocent laughing child?
I am so tired of politically correct garbage being pushed in schools. Why can’t a fifth grader go to class without being taught that he/she is responsible for destroying the planet? And we wonder why there is so much anti-social behavior among youth…..