A penny for the Old Guy
Cryosphere Today appears mostly repaired. Eli was looking at the Northern Hemisphere ice extent graph and there is quite an anomaly as we approach maximum ice cover. Place your bets. This graph will update so we can follow the changes in real time. Click for a better view
UPDATE: A bunch of cynical mice doubt the all knowing Eli, let us look at 12/31/07 picture as compared with that of a year ago, 12/31/06
2006 itself had an historically low ice minimum. Here those who are not John S (welcome back John, you look rested and medicated) can see that there is less ice cover both in the Bering sea and in the areas around Svalbard and Novaya Zemlya, but today's picture is astounding, look at the areas of clear(relatively) sea that have developed in a few days
The maximum temperature has been above zero for a couple of days and the forecast is for two or three more until it snaps cold again. Still, that must have been really thin ice that has disappeared!
Wednesday, January 02, 2008
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26 comments:
Is there some reason to expect it to look much different from last year? Note that at the moment it appears exactly on track to do so. Also, not to ruin the fun, but aren't we at least two months away from the minimum?
Is there some reason to expect it to look much different from last year? Note that at the moment it appears exactly on track to do so. Also, not to ruin the fun, but aren't we at least two months away from the minimum?
well, the point where the graph is crossing the "year line" seems to indicate the end of the fast growth in the past couple of years, as shown in the graph.
but let us wait and see. what do you expect? the top point to be higher than 2006? or 2003?
Steve Bloom, what are you saying, go wash your mouth out. Old Rabett wants to see anomalies, let him see anomalies. Ice not returning, although one of the Cryosphere diagrams shows 2008 new year ice extent is exactly as per 2007 new year, then let Rabett see lesser ice return. Approaching maximum ice cover, when again Cryosphere shows March as month of maximum, then who are we to quibble when Rabett can see lesser developed ice extent two months from now.
Big difference to last year is an early and continuing cold winter all around the arctic(defining how cold gets you banned) compared to 2007 winter.
So my guess Rabett, maximum ice extent for 30th March 08 is greater than any max since 2004, so 14m sq kms at a minimum. We have added 8m sq km, before the Cryosphere defined winter has even started, so whats another 3m sq km.
To the various Anons who will inevitably complain that its all about the ice thickness, well the polar bears will just have to tip-toe lightly around their bigger playground.
JohnS
John S:
"maximum ice extent for 30th March 08 is greater than any max since 2004, so 14m sq kms at a minimum.'
That's highly unlikely.
That would mean the delta -- min to max -- would be well outside the norm.
In fact, if the max this march did reach 14 million square km, that would make the delta since last fall greater by about 1 million square km than any delta since 1978
John S.
I know how mention of thin, new Arctic ice bothers you...something akin to fingernails running down the blackboard. However.
You said:
[To the various Anons who will inevitably complain that its all about the ice thickness, well the polar bears will just have to tip-toe lightly around their bigger playground.]
Well, how's this: come early summer and melt max time, the polar
bears can splash in their bigger swimming hole. That's not good.
John L. McCormick
Mention of the word "reality" to John S has the same effect.
John S:
Based on the data shown in the graph, the chance that you are right with your prediction that "maximum ice extent for 30th March 08 is ...14m sq kms at a minimum" is 1 in 10,000.
I wouldn't bet the farm on it, John.
Dunno if I'd rely on their charts til they announce that they've fixed their database, have you emailed them to check?
Could be they just forgot to take down the 'do not trust' notice of course.
But ... verify?
Verify is for wimps....
True I'm out on a limb here, but it is a cozy one with a special carrot box. Time will tell
Well said Rabett, verify is for the wimps. So lets carry on.
Plenty of space for ice area to grow into through winter. Bering Sea has been growing really well through autumn, so it will keep growing out. The Sea of Okhotsk, is just growing its ice area, so if those pesky Russians stop peeing into water, ice will continue to grow. Barents Sea is a bit slow, but ice growth continuing out from Greenland towards Spitsbergen, and will surround by end January, and close towards Russian mainland.
Good of the Anons to mention the delta change. I would have thought that the current delta change of 8m sq km to be pretty good, in fact some sort of record, particularly this occuring from mid October to end December. Would UNPRECEDENTED be apt. Most years in Rabetts graph, after end December have 2-3m more sq km of ice area added to reach ice area maximum. My 2008 winter is for 3 more to take it to 14m sq km.
I notice all of you have not entered into Rabett's contest and put forward a guess. Common, even you John McCormick, gladen a polar bear's heart, tell him how big his playground is going to be(even if he needs to tread lightly over some of it).
And what if we get to 14? O, I'm sorry, silly question. That will be weather, not climate.
JohnS
The critical thing is not whether the maximum ice cover gets to 14 million square km or any other 'magic' number.
The critical thing is what the min coverage is at the end of this year's melt season.
The entire arctic could be covered with ice at the end of this winter (not sure how many million square km that would be, but certainly greater than 15), but if the ice were all 1 cm thick, it would almost certainly all melt away by the end of summer.
Thickness IS a key issue, whether some acknowledge it or not and it is really almost a waste of time to debate the meaning of winter ice cover.
Oh, you Anons who talk about ice thickness, you are so last year. But to satisfy us all, Anons or John McCormick, take the end December, 3 January, any recent map ice map and tell us what is the ice thickness. Tell us what the ice thickness will be, say north of Greenland at end March.
JohnS
John S: "Tell us what the ice thickness will be, say north of Greenland at end March."
You still don't get it John. Forget about ice extent and ice thickness BEFORE the end of the winter season. That is NOT the critical thing.
What IS critical is the ice thickness AT END OF WINTER over what was OPEN OCEAN last fall (ie, new ice) because that will determine to a large extent whether it melts again by end of summer.
Sea ice thickness is not measured by satellite, but is based on submarine measurements, so it is only measured in certain places and even then only at certain key times .
oops looks like the disappearing ice has reappeared.
Hey anon from 9:35am. Are you willing to give 10,000 to 1 odds? I'll bet a dollar that it is 14mill square KM by March..
Jon P
Ah, but you seemed so certain that ice was "recovering" before, John S.
Apparently the talk about ice thickness is finally getting through and you are now having second thoughts and have taken my warning "Don't bet the farm" to heart, eh?
Incidentally, why should I give any odds in your favor?
The fools at Las Vegas regularly gamble away their life savings on games that they have little chance of winning and the casinos do not use the odds as a multiplier in their favor, so why should I?
Casinos also do not inform them of their odds of winning. If I were making bets with you, neither would I. :)
Ah, but I am not John S..
I see your confidence waning..
How's that RSS data you and Eli seem to like so much?
Jon P
Ah, but all you Johns seem to be the same -- at least when it comes to science.
FYI, Jon P (and anyone else not clear on this point), the models and the experts predict that the winter ice will continue a general recovery even after we start seeing a summer ice-free period. This is because the Arctic Ocean a) is a mostly constrained basin (meaning that the climatological boundary of the sea ice maximum is in most places farther south than the land boundary) and b) will have to get a lot warmer before it can support late winter open water much north of where it's prsently observed. So for now the only thing that's very interesting about the winter ice is thickness. There should be a slight downward winter area trend, but nothing like what the summer ice is doing right now.
The particular behavior Eli just pointed to might be interesting, but that would depend on how common such fluctuations are.
One other thing: It's important to know what the metric is for these plots and graphs. IIRC (it's on the site somewhere) UIUC uses 85% or greater coverage coverage based on sat photo pixel albedo. At 85% new ice is basically slush, so ephemerality should be expected.
Two other thing: NSIDC thinks that UIUC is overly bold in using area rather than extent (the difference being small areas of open water like leads) and in producing a daily product at all (since sat photos are hard to interpret accurately). Consistent with this and as we just saw, UIUC's automated data process has been known to have the occasional train wreck. OTOH there would be nothing so boring as trying to stay awake while watching NSIDC's monthly average extent plots.
Steve is probably right, but Eli is having a lot of fun with this. It's going to snap cold in Svalbard next week and we will see how fast the ice closes. We have adopted a Norwegian weather frog for the winter.
As to NSIDC and UIUC, well I think you use both products and if you are serious make use of the strengths of both while noting the weaknesses.
RE: the graph
NOTE: The timeseries graphs on this site are currently incorrect. We had a hardware problem corrupt the data and are currently recreating the timeseries from original data sources. Expect the correct data in 5-7 days. We apologize for the inconvenience.
Many thanks, may I take it the maps are correct??? Points to Steve Bloom
AFAIK the maps themselves are fine. While we're on the subject, I assume the shading indicates degrees of concentration with the reddest shade on the edges being at or close to the 85% level, but it's hard to know for sure due the non-obvious or perhaps largely non-existent site documentation.
Just to note also that the daily sat data is available in digitized form on or via the NSIDC site, so the ambituous young Arctic hares can roll their own.
BTW, what I find most interesting about this year's map vs. a year ago is not so much the lessened cover on the Atlantic margin overall but the relative lack of inshore stuff (along western Novya Zemlya and the adjacent Russian mainland). OTOH this would probably mean nothing if ice comes and goes from the map depending on whether it's at 84% or 86%.
Finally, it seems a little weird for ice to be shown in the morthern Caspian Sea, but maybe that's normal.
Eli,
How about Antartic Sea Ice extent comparisons? Start another blog entry..
Like these..
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ANT-ARCHIVE/ant.20080108.jpg
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ANT-ARCHIVE/antarctic.0.2007010810.jpg
You do agree we have TWO Polar ice caps, right?
Jon P
I wouldn't agree with that. That's temporary sea ice at the North Pole, not an icecap.
Remember the newswire?
> May 17, 2000
> Anchorage, Alaska -- Five
> adventurers ... were rescued from
> the North Pole after their
> biplane broke through the ice
> and sank ....
You're looking for this, I think:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg
Hank,
Excuse the layman, I stand corrected.
Is there a chart the breaks out artic and antartic into seperate trend lines?
I have looked unsuccessfully..
Thanks
Jon P
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