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Thanks for the comprehensive update. I believe we might be in for a few surprises in 2011 as far the weather is concerned. Last year we had an extremely negative AO at this time of year and a late sea ice growth; this year a significantly positive AO seems to produce similar effects. I read somewhere ( I wonder if it was Wayne Davidson or someone else on this blog) that La Nina might have a delayed effect on the Arctic weather. Well la Nina seems to be winding down now, so we could expect some ripple effect on the Arctic weather this summer. How will this affect the melt, i am not sure but may be someone might have an idea?


More about the possible effects of La nina on Arctic weather.

I found this interesting page on the Alaska Climate weather centre. If you look at the graph, you will see that 1999 and 2008 were "cooler" years in Alsaska, both years being "la nina" years. Apparently we could also be in the cooling pase of the PDO , which might have an effect as well?

Artful Dodger

Farewell From the Arctic, ICEX 2011.
29th and final blog post from Jeff Gossett in the Beaufort Sea.

Artful Dodger

Neven, can you embed this "cool" video of the USS Connecticut surfacing during ICEX 2011?

Lord Soth

Other than being less ice than 2010, the pattern between 2010 and 2011 is quite similiar.

However it is now April 2, and I believe the chances for a new maximun is extremely close to zero, as the scale tips more towards melting.

However, with the ice being a lot thinner, it is easier for ice to spread out, so this flat line behavior we saw in 2010 and now 2011 in the second half of March, will probably become the new norm.

Gas Glo

>"However, with the ice being a lot thinner, it is easier for ice to spread out, so this flat line behavior we saw in 2010 and now 2011 in the second half of March, will probably become the new norm."

I am probably being dumb but how is it easier for ice to spread out?

Do you mean extent to increase without area increasing via leads opening wider out? Problem here is that area and extent have both been increasing. This year, I suspect it is new very thin ice forming because the extent is unusually low. That doesn't stack up for last year which had high extent. So I am thinking different reasons in different years and don't see the logic for 'become the new norm' from the two years.

New very thin ice forming because the extent is unusually low may well become the norm but I don't see two years of it yet.

Perhaps I am missing something obvious?

My first thought was: if ice is 3m thick and a long 2m wide sliver cracks off then the ice rotates and area is increased by 1m*length of sliver and thickness reduced by 1m. If the ice is only 2m thick such a sliver has no reason to rotate and area and thickness remain unchanged.

This would mean that extent is less likely to increase with thinner ice.

OTOH perhaps there is more cracks earlier in the season and there are also 1m wide slivers cracking off which do increase the area. Perhaps we are getting this out of the way earlier in the season and there will be less of this later in the season?


Somewhat OT, but I just watched an interesting movie on PBS (US Public Television) based on Lester Brown's book,
"Plan B". It's available in streaming video at:


One of my favorite quotes from it was:

"We need to mobilize people to confront a gas you cannot see, touch, or smell, and which will primarily affect their unborn grandchildren."

My one wish is that Lester Brown would make more specific suggestions -- e.g. specific legislative proposals to advocate for. Advice such as "We've got to restructure the global economy" doesn't lead to actions we can "do". My daughter, upon hearing this, remarked that one thing which has always bothered her was T-shirts and bumper stickers which say "SAVE THE WORLD" -- how can such vague advice compete with "DRILL, BABY, DRILL"?

Gas Glo


Gas Glo

maybe revenue neutral

is more sellable?


Yes, "Carbon Tax Now" is more like what I had in mind (but the link to your revenue neutral picture is missing).

Given that the show is 90 minutes long, spending 10 minutes or so describing the effects of a carbon tax would would really have helped that show tremendously.

Gas Glo

Only a mistake. It was only meant to be:

Revenue Neutral

Right clicking the duff pic may have told you that I just ripped off the pic from our old friend William Connolley here:


(must remember to use preview more)

R. Gates

Another excellent update.

I do think the very positive AO over the past few weeks has given rise to the flattening of the sea ice extent curve, but this will only hold for a few more weeks at the most, as overall air temps and insolation begin to increase rapidly. Yes, we will have some surprises in this years melt, but most surprising I think will be what happens in the late summer. Last year, after a sharp decline early in the melt season (May & June), we saw a less precipitous but still steady decline in July and August, with a few final late dips in early September.

This year, I think it will be be steady all melt season, weaving above and below 2007's extent trend line, but I look for a much steeper decline in July and August than we saw last year. Wind and weather are always a variable of course, but I feel that the La Nina is not as big a factor as the deeper ocean temperatures that have been increasing over the longer term in the deeper waters moving into the Arctic. These, more than La Nina, are the long-term forcing event for the Arctic, and the large amount of energy this deeper ocean heat represents will overpower any short-term fluctuations. True, this increase in deeper ocean heat moving into Arctic waters represents only a tiny fraction of Trenberth's "missing heat", but still, that heat is enough, given the overall polar amplification of AGW and overall shrinking ice volume, to keep the steeper downward trend in sea ice extent in tack. Remember, late in the season it is the heat in the water, and not the air that determines late season melting. Lot's of heat coming in from these deeper currents and of course being created by more open water early in the season.

In short, look for 2011 to give 2007 very strong competition for lowest summer sea ice extent on modern satellite record.


May be it is my poor eyesight but the NSIDC graph shows that we have a new maximum. Could not confirm with IJIS as the site appears to be down. But Uni Bremen also seems to indicate that we might have passed the maximum reached in early March.


Sorry, the UniBremen graph is here

Gas Glo

Want to try this eyeball upgrade technique?

Gas Glo

Preview and post look different with that. Try the link:

R. Gates

We very well could have seen a new maximum set with this latest "bump up", but like last year, this is a deceptive kind of maximum, as it is primarily caused by this late season divergence of the ice with the the positive AO. With the warmer than average Arctic temps, any true growth in ice is going to definitely be only a few inches thick, which means, such a "bump up" coming when the melt season is ready to begin, often lead to rapid periods of decline as that new thin ice melts very very quickly, as we saw last year.


Gas Glo

I agree. My eyeballing techniques may be a bit rough. We'll need to have the numbers before we can be sure.

R Gates
I agree; a new maximum would only be "headline stuff" but would not change the fundamentals. The overall extent is still way below the average and it is likely to fall very fast once the melt really starts.

Lord Soth

I check the graph, and no new maximun. Also the NSIDC site is a running 5 day average, so the last few points on the graph ussualy gets toned down as the averaging takes effect.


IJIS has reported again. It could be that the first century break of the season is in the making: -124K. I have a feeling the revision will change all of that.

It is safe to say that it's out of the question that IJIS will report a new maximum.


It looks like IJIS is constantly revising (upwards) their previous estimates. The SIE value for April 1st has been revised 3 times!It is now 13,762,656. The original estimate was around 13,737,000
Is it a problem with pixels having been overlooked? Last year we generally had one smallish revision( up or down).


Indeed, Phil. I had to go back and check all the numbers for February, as some of them had been changed again (after the afternoon - for me, here in Europe - revision). It'll probably settle down after a while when thin ice isn't forming overnight anymore.

Gas Glo

[quote crandles]I think it is unreasonable to expect William to lose if there is an unbelievable downward spike that only exists for a day or two.[/q]

[quote neven]If something unbelievable like that happens, it would mean that WC had unbelievable odds stacked in his favour. In that case he shouldn't moan when something unbelievable happens.[/q]

Not sure I follow. Maybe you are just nudging wc's thread?

If the lowest consecutive 9 days showed
3.33m km^2
3.34m km^2

*** indicates a suspect number

you would obviously lose your monthly average less than 3.2m but you could claim to have won the daily minimum less than 3m bet. I think in such circumstances it isn't credible that there has been a 330k plunge one day followed by a 320k rise the next and in such circumstances you should lose both proposed bets. I was thinking it is better if the bet terms make this clear so there can be no argument even if it is extremely unlikely. It seems WC doesn't like the complexity even if he seems to agree that "I don't think huge downward spikes are possible, without errors in the dataset".

Anyway, I don't see where you are getting "it would mean that WC had unbelievable odds stacked in his favour" from in this respect. If the lowest few days were
there is no question that you will have won. So you can claim to benefit from an unbelievable downward spike but you cannot lose from an upward spike. That seems asymetrical and could have been a valid reason for WC holding out for using monthly data. This is pretty irrelevant now it is clear WC wanted to 'work the numbers' rather than being concerned about spikes.

I think my proposed bet terms are the way to show that WC is wanting "unbelievable odds stacked in his favour".

I don't think he will bet with me if much better terms are on offer but I posted my proposed terms to try to show how different the bet terms would be if WC was really willing to bet on reasonable terms on what he is saying.


Gas Glo, I appreciate your effort, but when betting small amounts it doesn't have to get very complicated. Betting that SIE minimum will go below 3.5 million is very dodgy for me, because it would take 2007 weather conditions, which do not happen every year. Sure, if all the speculation regarding volume is more or less correct, it will take less than 2007 weather conditions to achieve. But we're not even talking 3.5 million km2, WC wants to bet on less than 3.0 million km2!

Those odds are nuts statistically speaking, but I'm willing to bet just for the fun of it. And for the extra fun I want to bet on daily numbers. It's all very, very simple really. I hadn't even contemplated some software or sensor fluke.

I'll wait for WC to recalculate the numbers (yawn). But if it's not daily numbers, I'm not betting.


Interestingly the Antarctic is showing a wee bit of an anomaly again.

Artful Dodger

April 3 may be the first Century Break of 2011: Preliminary Extent has dropped 119K over the prelim. for April 2.

April 3rd Prelim = 13,598,594 km^2.

Gas Glo

or may not:
Graph page updated to prelim 13,598,594 but download page says:

4 2 2011 13722969
4 3 2011 13632344

Artful Dodger

yup, only a 90.5 K drop, (pending further revision :^)

Artful Dodger

Arctic Sea Ice Maximum 2011
NASA Animation Sep 16, 2010 - Mar 16, 2011


Awesome, Lodger. Thanks a lot for that one (I also saw your ICEX vid, which I might use for another piece).


Here's a first image of the March trend line from NSIDC:

Nightvid Cole

I think this is a direct effect of the ice-free Gulf of Saint Lawrence. Normally the Gulf is almost totally frozen in early March and melts over the next weeks, being clear around April 15 or so. The Gulf of Saint Lawrence is normally the first place to start melting (beginning in Mid-March) followed by the gulf of Finland and Gulf of Bothnia (beginning in late March, clear by about May 20) and then the much larger Sea of Okhotsk (beginning around April 1, mostly open water in late May). Both last year and this year had a virtually ice-free Gulf of Saint Lawrence already in Mid-March, so there is nothing to melt. This explains the delayed melt onset both last year and this year: We have to "wait" for the melt to begin in the places that start a bit later.


Holy cow, a drop of 142K reported by IJIS. What the h*ll is going on? Is it time to throw the PIPS-arrows-forecast-model out the window?

That's it, I'm going to bed.

Gas Glo

"What the h* is going on?"

So 3 April went from
13,598,594 to
13,632,344 to

upward revisions total 53k; latest fall for 3rd April only 71k.

4 April started 13,492,500 to 13,540,469 an upward revision of 48k and probably more to come. So the upward revisions haven't got bigger than the daily falls - at least not yet...

IJIS show average March extent as 13,745k 3rd lowest above 2006 13,513k and 2007 13,718k. Area graph would also seem to suggest 3rd lowest.

NSIDC figures:
2006 3 Goddard N 14.43* 12.44
2007 3 Goddard N 14.65 12.49
2008 3 PRELIM N 15.23 13.17
2009 3 NRTSI-G N 15.16 13.04
2010 3 NRTSI-G N 15.10 13.11
2011 3 NRTSI-G N 14.56 12.40*
* record low

So NSIDC has March 2011 as record low area for March and second lowest extent.

Artful Dodger

ICEX 2011 Demonstrates Naval Research Projects:

Chief of Naval Research Rear Adm. Nevin Carr visited the ICEX operations center and spent time aboard USS Connecticut (SSN 22), the advanced Seawolf-class submarine that participated in this year's exercise.

Lodger, coincidentally I've just posted my short article on this: IceBridge, ICEX, Catlin Arctic Survey.


Record ozone thinning looms in Arctic


I wonder how this might play into the Arctic melt...

Gas Glo

CT has updated. NH anomaly has increased to only -0.652

While SH has decreased to -0.689 so we now have a lower SH anomaly than NH anomaly!

SH has only had less ice area at this time of year twice before and that was 1980 and 1981!

Patrice Monroe Pustavrh

CT readings are really strange. What bothers me, there are some really strange changes in area:
- IJIS area went down at same time CT went up
- uptick in St. Lawrence area - according to wetterzentrale reanalysis for 850 hpa level, temps there should be above 0 and with southerly winds, there should be no export
- Upticks in all areas, and some of them are really extreme
- 100% coverage in Hudson bay area, and Uni Bremen shows areas of open water there
These readings are strange. Now, the question is why there are such differences - were previous values lower than actual, or current values are too high or all these values have some error and this is well within it. Any clarifications would be well appreciated.


I agree. Things look a bit chaotic in dataland, what with all the intervals of no data reported (no TOPAZ update since Feb 24th). I'm sure it'll clear up in a few weeks.

I figured CT area would go up, as for instance that huge lead off the coast of Novaya Zemlya has frozen over in the past week. But I didn't think it would go up this high. And the anomaly jumping from -1 million km2 to 600K km2!

Although the winter maximum hasn't been 'broken', it has essentially flatlined for quite a bit of time. Fascinating.


NSIDC is back with an update.

Peter Ellis

The CT data is only up to 2nd April, exactly the peak of the recent uptick. Watch for it to drop again in their next update.

Gas Glo

If you want to compare ice age March 2010 vs March 2011 (NSIDC update shows March 2011 and 79-2000 Median ice age pics):



I have done this comparative: http://diablobanquisa.files.wordpress.com/2011/04/multiyear-sea-ice-march-2010-2011-e1302039735437.png?w=600


But I don`t know if we are comparing two different versions.

Note: James Maslanik and colleagues recently recalculated their entire series of ice age data based on a minimum of 15% concentration. The old version used a 40% minimum. The reprocessed ice age data is therefore more consistent with other measures of sea ice, including NSIDC sea ice extent data, which use a threshold of 15%.

Artful Dodger

Hi Peter,

The latest CT YearFrac is .2548
I make this as Apr 04 2011 00:00
So the Latest Day is Apr 3, 2011.

How are you calculating April 2nd as the latest day?

I think there is also some data misalignment because IJIS uses a 2-day running mean SIE (at least for the final value), and CT SIA is a single-day value.


Peter Ellis

Um, where are you getting your data from? I got it from http://arctic.atmos.uiuc.edu/cryosphere/timeseries.global.anom.1979-2008

So far as I'm aware this is the exact data CT plots, and it's held on their site. The latest value is 2011.2521

0.2521 x 365 = 92.0165, i.e the 92nd day of the year, which I calculate to be April 2nd.

Peter Ellis

Ah hang on, they start their numbering at zero, so you have to add a day. That makes it the April 3rd value, as you say.


Lodger - are you still maintaining your CAPIE figures? I'm guessing they've crashed pretty hard over the last week or two? IIRC, you have data for several years - how does 2011 stack up so far? "Instinct" (LOL) says we are looking at a more diffuse pack...?

I only ever maintained my IJIS Extent -v- Area data for April to October, so I'm just dusting off last years spreadsheet now.


Artful Dodger

Hi Frank. Sure mate, my spreadsheet automatically calculates CAPIE. Keep in mind these are subject to change if CT revises their NH SIA values:

Date:	CT Area:	IJIS Extent:	CAPIE:

Mar 25 12,761,156 13,732,344 92.93%
Mar 26 12,814,289 13,743,750 93.24%
Mar 27 12,926,113 13,740,469 94.07%
Mar 28 12,913,782 13,718,438 94.13%
Mar 29 12,913,234 13,697,500 94.27%
Mar 30 12,956,662 13,707,969 94.52%
Mar 31 13,028,717 13,753,438 94.73%
Apr 01 13,043,460 13,762,656 94.77%
Apr 02 13,080,165 13,722,969 95.32%
Apr 03 13,095,293 13,651,875 95.92%

Again, subject to revision, Apr 03 would revisit the previous 2011 high CAPIE value which occurred on Feb 21.

Gas Glo

Hi Lodger, how does that 95.92% compare with this time of year for last 3 or 4 years?


A team of researchers from UCL Earth Sciences departed today for the Arctic to test how well sea-ice thickness is measured by the European Space Agency’s ice satellite CryoSat-2, which originated at UCL.


Artful Dodger

Year: MAX: Date:
2005: 98.00% Jan 20, 2005
2006: 97.62% Apr 08, 2006
2007: 96.73% Feb 27, 2007
2008: 96.21% Feb 16, 2008
2009: 97.67% Apr 04, 2009
2010: 96.29% Mar 22, 2010
2011: 95.68% Feb 21, 2011
(2011 Provisional)


Is the MASIE NH Extent for days of (a mistake)

2011094,,,,,, 14907644.98

2011095,,,,,, 14543365.90

Difference of - 364,279.08

Now, that is a "Century Break"


Gas Glo

I cannot get masie to open. Last day I have is 087. Is it me struggling or everyone? Perhaps Jack tried at a time when they were attempting to resurrect it?

Christoffer Ladstein

Apart from the Novaja Zemlja region it seem to be quite harsh in the Artic still, these days, too cold to expect any huge drops in extent for the coming days?!

Anyway, here's a couple articles regarding the acceleration of the icemelt in Greenland & Antarctica AND a nice one about a rather tantalizing arctic pool of freshwater!
http://www.cicero.uio.no/fulltext/index.aspx?id=8747 (in norwegian, http://www.agu.org/pubs/crossref/2011/2011GL046583.shtml (english abstract from the original magazine),

Gas Glo

Masie seems available again:

The extreme 364k fall is still there. Century breaks (-118,795)for (6) Barents_Sea alone and (-100694) for (7) Greenland_Sea alone seem quite extreme.

There is a 137k bounceback from the 364k fall.

Bering sea is the one that shows the big bounceback up 56.2k after falling 55.7k. Greenland and Baffin also show sizable bounces of +31.8k and +28.7k.

Gas Glo

PIOMAS has updated volume to 3rd April. :D


Some more comments by Dr. Maslowski:

The original prediction, made in 2007, gained Wieslaw Maslowski's team a deal of criticism from some of their peers.

Now they are working with a new computer model - compiled partly in response to those criticisms - that produces a "best guess" date of 2016.

Their work was unveiled at the European Geosciences Union (EGU) annual meeting.

The new model is designed to replicate real-world interactions, or "couplings", between the Arctic ocean, the atmosphere, the sea ice and rivers carrying freshwater into the sea.

"In the past... we were just extrapolating into the future assuming that trends might persist as we've seen in recent times," said Dr Maslowski, who works at Naval Postgraduate School in Monterey, California.

"Now we're trying to be more systematic, and we've developed a regional Arctic climate model that's very similar to the global climate models participating in Intergovernmental Panel on Climate Change (IPCC) assessments," he told BBC News.



Just roaming around the MODIS mosaic and thinking short term, until the melt starts properly.

I can't help think the Kara Sea is going to lose a lot of ice coverage over the next week or so:
*Winds backing to anticlockwise, pushing ice to the east.
*Good pool of warming water off Novaya Zemlya
*warm air moving in from the southwest
*Oh, and have you seen the pack there? I've had better crusts on a grazed knee...

Not to say ice won't come back when the wind veers easterly again, but for now, I'd expect a dip in the total there.

Just testing my forecasting....

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