UPDATE: Regular Sea Ice News now posted here:
Sea Ice News #25 – NSIDC says 2010 3rd lowest for Arctic sea ice
=======================================
Normally I have a Sea Ice News feature on Sundays.
I’m holding it a day, because I’m waiting for NSIDC to make an announcement, and I want to include it. Arctic Sea Ice is making a quick turnaround, the DMI 30% graph shows we are now at 2005 levels for 30% extent.
While waiting for NSIDC in the meantime, have a look at this interesting animation showing the quick turnaround in ice extent in September…
Steve Goddard writes:
Blink comparator showing ice growth over the past week. More than 5,000 Manhattans of new ice have formed – one new Manhattan of ice every two minutes.
http://arctic.atmos.uiuc.edu/CT/animate.arctic.color.0.html
Also while waiting, don’t forget to check status at the WUWT Sea Ice Page.
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jakers says:
October 4, 2010 at 1:43 pm
Several people have made similar remarks in the last few weeks, including you last week IIRC, and I don’t buy it. Here’s why:
JAXA extent increase from the minimum = 983437 km^2 (20.4%)
CT area increase from the minimum = 942295 km^2 (30.7%)
So the relative area has increased ~50% more than the relative extent since their respective minima…how could dispersion alone lead to that? AFAIK, it can’t. Please let me know if that is an incorrect conclusion and provide a mechanism for support. The only decent argument I can think of against my conclusion is that the area had been increasing for ~10 days before the extent minimum. However, the extent/area ratio was 1.45 on Sept 18, and it’s currently 1.44, so that argument is weak at best. Looking at yesterday’s gains, I can see why one would argue that the single-day gain was mostly wind-driven, as JAXA extent gained 129843 km^2 and CT area gain was a weak 53148 km^2. But if one makes that single-day argument, then it just strengthens the fact that the rest of the gains before yesterday were freeze-driven.
Also note that, despite the recent slowdown, the minimum-to-Oct 3rd increase in extent is the second largest in the JAXA record (only behind 2002). The same metric for CT area has 2010 being the 2nd best in the last 10 years (only behind 2001).
I think the only reasonable conclusion here is that, with respect to the last decade, the refreeze has indeed been rapid this year. That doesn’t at all answer the more pertinent question as to whether it matters much. Personally, I don’t think it does (which I imagine most of the skeptics here will disagree with), but I need to analyze the numbers in more detail to really say that with any sort of confidence.
-Scott
R. Gates says:
October 4, 2010 at 11:27 am
When N. Sea ice, (and even global sea ice for that matter) get above the long term average, let me know. Then we might have something interesting to talk about. As it stand, N. Sea ice has not been above the longer (30+ year) average since 2004…quite in line with what would be expected from GCM’s taking AGW into account. This really upsets AGW skeptics, but those are the facts…now let’s hear the whining.
Always with the disingenuous arguments (You see, I give you credit for being misleading rather than ignorant, although I really have no way of knowing which is truly the case.)
The Arctic minimum will continue to wallow “in recovery” regardless of annual global temperatures because the ice volume low reached represents a cumulative energy gain that has to be dissipated by natural forces over time. It simply won’t turn around on a year to year basis – it’s not as if that energy balance is zeroed out every year. It’s similar to the difference between budget deficits and debts: you can run many years of budgets without a deficit (ie, a surplus) but still remain in debt if that debt is great enough.
Unlike water/ice, the atmosphere has relatively little energy, and thus rapid temperature changes can occur that represent very little energy accumulated or lost. In other words, atmospheric temperatures can vary significantly from one year to the next without representing a large (relative) energy change.
So, let me know when you can demonstrate that the amount of Arctic ice is dependent on atmospheric temperatures more so than sea temperatures and that the atmosphere warms the sea instead of the other way around. Then we might have something interesting to talk about.
The 2007 Arctic minimum certainly sticks out like a sore thumb in regards to extent or area, but what happened in November 2006 when there was seemingly little or no ice accumulation? Did this lead to or help move the sea ice towards the 2007 minimum?
Daniel M says:
October 4, 2010 at 3:21 pm
Yes, I was sort of trying to get to that in the Sea Ice News #24 thread…does the a rapid refreeze make a difference? 2006 had a very slow refreeze and 2007 was then the largest single-year loss ever. 2007 had a late-starting, but rapid, refreeze and we saw some gain in 2008. 2008 then exhibited a very rapid and early refreeze and the 2009 gain was very good (best in JAXA extent since 2002, 3rd best in CT area since 1979). However, 2009’s refreeze was slow, and we saw 2010 go back down to 2008 levels…
So, does a rapid refreeze matter much? I’m still leaning towards “no” or “only a little”, but the anecdotal info above seems to disagree with me. If it does matter, the mechanism would likely be in the quality of the first-year ice in the following summer. With a little extra time and colder weather, there could be a big difference in the quality/thickness of the 1st year ice which would make a difference in the melt season. A similar mechanism might be that a slower refreeze gives more time for wind to crack the ice?…dunno about that one. Naturally, older ice would also be affected by the rapid refreeze (both mechanisms), but not on the same percentage basis.
I need to dig into the numbers here, but I’m short on the time to do so right now.
-Scott
Anything is possible says:
October 4, 2010 at 2:13 pm
http://www.wunderground.com/climate/SeaIce_Fig04.asp
Interesting that this chart shows a marked decline in Summer Ice Extent in the early 50′s, not long after the warming phases of the PDO and AMO (c.1910-1940) came to an end.
What we are seeing now would seem, on the face of it, to be a repeat performance, with the latest warming phases of the PDO and AMO coming to an end c.2000, and a decline in Arctic Sea Ice summer extent coming a few years later.
Hmmm……
_____________________________________________________________
Well if you looked into it some more, you’d find that prior to 1950 the data is largely derived from a “climatology” (e. g. not much real world data exists for this era) while the era from 1953-1978 (or maybe 1972/3, TBD) was largely derived from Arctic sea ice charts, and of course the 1979-2010 (0r 1972/3-2010 and ongoing) are from the modern satellite era.
So the “drop” from 1952 to 1953, is, for all intents and purposes, an artifact of the dataset eras, and not due actual real world conditions at that time.
Response to EFS_Junior @ur momisugly 4:22pm
Russian Arctic Ice Charts – released in 2007 – date back to 1933, while the Canadian and American Ice Charts started in 1968 and 1972 respectively.
I can’t anything specific that would dramatically change the dataset eras in 1952-3, but if you know different, pray tell.
Interestingly the abstract of this analysis of the Russian Arctic Ice Charts (Mahoney, Barry, Smolyanitski & Fetterer, 2008) http://www.agu.org/pubs/crossref/2008/2008JC004830.shtml
tends to support my (very tentative) hypothesis.
R. Gates says:
Bob from the UK says:
“You can expect the ice to recover to at least those levels of the 1970′s.”
____
This is very very unlikely.
I agree looking at the fact that we are entering a solar minimum at least as weak as the Dalton minimum, returning to the levels of the 1970’s is a significant underestimate.
Phillip Bratby says:
October 4, 2010 at 2:29 am
“Gareth: Don’t you just love SI units. Area = Manhattan or Wales. Volume: How many double-decker buses are there in an olympic swimming pool?”
Depends how good their brakes are!
Would they fit in at all, I wonder, given that a double decker bus is as tall as half a football pitch on its side (or half a penalty area on end … or something)? Wouldn’t they just stick out?
Gerald Machnee says:
October 4, 2010 at 1:15 pm
“RE: eadler says:
October 4, 2010 at 9:50 am
***It seems that there are posters here, who do not know that there are graphs, which show 100 year data for Sea Ice extent. Ship log data has been calibrated as a proxy for the satellite data to get this.
http://www.wunderground.com/climate/SeaIce_Fig04.asp
It shows a convincing declining trend in the summer sea ice over the past 30 years after the first part of the 20th century, during which it varied in a narrow statistical band of about 1/- 1.5MKm2, and that the winter ice, as would be expected has been stable for a longer period of time and has declined very little. ***
With respect to this site above, this was hashed over at Climateaudit two summers ago. The apparent straight line should not be taken too seriously. The compilers issued a caution statement that there was a lot of estimation and extrapolation used. After that there was a reference to other charts which used Ship data including that from Russia, showing a much more variable ice amount.
What we have here is a hockey stick which tacks on 30 years of satellite data to several types of reports.”
If there are alternative charts, from other sources, that show more variability of the Arctic Sea Ice Extent deduced from ship logs, that have been published in the peer reviewed literature I would like to see them. I am not impressed by what I read from bloggers on AGW denier web sites.
The original hockey stick paper did underestimate the statistical variability of northern hemisphere temperatures, as was shown by many subsequent papers, that did a variety of statistical analyses, and all showed that the hockey stick characteristic was still present.
Alan Bates says:
October 4, 2010 at 3:44 am
“* Wiki claims as their source the US Census Bureau although the references do not seem to link to the information. I can see no reason to doubt the figure.”
You see no reason to doubt the figure!!! From Wiki!!!
I’d doubt Wiki even if it told me humans have ten toes!
In fact, I propose a new measure of information content, loosely related to the baud; the wikibit shal be defined as the average length of wiki article per bit of valid information. I estimate that 1 wikibit ~ 10kbit raw data. 🙂
Eadler says:
If there are alternative charts, from other sources, that show more variability of the Arctic Sea Ice Extent deduced from ship logs, that have been published in the peer reviewed literature I would like to see them. I am not impressed by what I read from bloggers on AGW denier web sites.
No there isn’t but then the chart you posted was unreliable not really scientific, relying on some observations, I’m not in the slightest impressed with anecdotal evidence of that nature.
However polar glaciation is something for which there is reliable scientific evidence, as there is on temperatures in Greenland, which I think you would agree gives an indication on the variability of the Arctic climate and hence ice extent.
Professor Easterbrook has an excellent paper.
http://myweb.wwu.edu/dbunny/research/global/glopubs.htm
I find Warmist blogs base their arguments on unsubstantiated facts from IPCC reports such as the verbal comments on the disappearing Himalayan Glaciers, which as we all know turned out to be complete nonsense.
Any scientific discourse on polar ice can’t ignore the evidence in the peer reviewed literature on variations in polar glaciation and temperatures derived from ice cores in Greenland.
PIOMAS shows the 60-year Ice/PDO cycle as quite different from the Cryosphere’s GW-like constant decline: The Low Ice Record of 1954 is not again reached until 2002 (the cold La Nina of that year & the next is the RECORD La Nina in the last 60 years) (bottom of the page, past the Sub Charts: note how the explanation below the Ice Volume Chart, tries to pass off the up-n-down “wave” trend as just “a few years in the 1950s” — that is the Most reliable kind of proof: from someone who does not WANT to show it. In History, one is always suspicious to take something as SOLE PROOF if it is put forward by someone who wants to find just exactly that. — PS this does not mean Cryosphere is neccessarily Wrong: their Extent could fall and yet Volume rise – – as Sunspots continually increased for near 200 years until a stunning collapse a year ago, maybe the Winds had a Continuous change that concentrated Ice ! And thus, logically. predicting the reversal this year, when the Winds dispersed it. Hmmmm ???). http://psc.apl.washington.edu/IDAO/retro.html
From eadler on October 5, 2010 at 5:45 am:
Aren’t they cute when the drop the pretense of being reasoning and just go for the insults?
☺