Sea ice extent update 22: in the face of adversity

I'm regularly writing updates on the current sea ice extent (SIE) as reported by IJIS (a joint effort of the International Arctic Research Center and the Japan Aerospace Exploration Agency) and compare it to the sea ice extents in the period 2006-2009. The IJIS graph is favoured by almost everyone, probably because it looks so nice compared to other graphs (like the one by Arctic ROOS, the University of Bremen and the Danish Meteorological Institute). All the years have a nice colour of their own which makes it easy to eyeball the differences between trends. Most of the betting on minimum SIE is based on the IJIS data. NSIDC has a good explanation of what sea ice extent is in their FAQ.

August 5th 2010

Despite weather conditions that have slowed down the rate of Arctic sea ice melt in the weeks that matter the most, 2010 has doggedly persisted and is still clinging on to that second place in the great ice melt race. Weeks and weeks of winds blowing from the North and stalling of the Beaufort Gyre have spread the ice pack out over the Arctic Ocean, leading to 'holes', patches of relatively low ice concentration, in the interior of the pack. If these holes get any bigger, we might witness the separation of areas with multiyear ice from the central ice slush. I wouldn't be surprised if that was a first in the satellite era.

Whereas trends on most area graphs (such as this one from IJIS) have turned sideways, extent melt rate seems to have picked up in the last week. For the last two days of the previous SIE update melts of around 80K were reported and this trend has continued. For August 1st we even witnessed a small century break of 102,500 square km, the 11th of this season. In the days after that the consecutive reported melts were 88,281 for August 2nd, 76,250 square km for the 3rd and today's final reported number came in a bit lower after a 21K upwards revision: 61,719 square km.

2010 has been increasing its lead over 2009 and is so far managing to keep 2008 at a relatively safe distance of over 300K square km. 2007 had a few century breaks in a row during this period, but unlike 2008, that will keep sprinting well into September, it is going to run a bit out of steam next week. Still, it has a huge lead of almost 600K square km over 2010, so it makes no sense to start speculating as of yet.

The current difference between 2010 and the other years is as follows:

• 2006: -286K (37,697)

• 2007: +592K (57,041)

• 2008: -315K (70,333)

• 2009: -177K (48,654)

The average daily melt for the month of August is between brackets. 2010's average daily melt for August is currently 82,188 square km per day, but it is bound to go down as the month progresses.

And here's the IJIS sea ice extent graph:

The trend on the Cryosphere Today sea ice area anomaly graph has been going up and down and is currently more or less holding steady around -1.5 million square km compared to the 1979-2008 mean. The Arctic Basin as well as the East Siberian Sea are continuing their decline, slowly but steadily. Here's the anomaly graph:

It's bit premature to tell, as these weather forecasts change continually, but it looks as though weather conditions might switch to ice melting/transporting/compacting conditions in about five days from now. Both the European Centre for Medium-Range Weather Forecasts (ECWMF) and NOAA's Global Forecast System (GFS) - go to Wetterzentrale, click on the weather forecast models on the left and choose Northern Hemisphere 500 hPa SLP or Bodendruck - are forecasting a big high pressure system over the Beaufort, a key condition for the positive Arctic Dipole Anomaly:

 

I'm not seeing the same highs yet on this forecast map put out by Unisys, which is based on the GSFx model (perhaps one of the commenters can tell me if that's the same model as the one by GFS):

                

If this high starts developing for real I believe this would entail the Arctic Oscillation shifting to a negative phase. Right now it is still quite on the positive side, as we can see on NOAA's AO Index, but we should keep an eye on it the coming week:

Let's wait and see if the in situ melting and holes in the interior of the ice pack get replaced by big winds, big waves and thus ice melting, compaction and transportation. If the ice is as thin as some expect, things might get spectacular. Well, at least, the clouds will subside and we gain a better view of the Passages and other areas of interest.

TIPS - Other interesting blog posts and news articles concerning the Arctic and its ice:

A HUGE chunk of ice has broken of the floating ice tongue in front of Petermann Glacier. Patrick Lockerby has the details.

Ron Lindsay, scientist at the University of Washington's Polar Science Center, has updated his prediction for Total Ice Extent in September: 3.7 +/- 0.3 million square kilometers. That's low.

ClimateProgress has a new summary of current conditions in the Arctic.

Over at the Chatter Box Patrick Lockerby keeps churning out must-read articles. He has already published a first update of his Arctic Ice August 2010 analysis, posted a few days ago.

Our modern Arctic heroes from Norway are sailing north along the Yamal Peninsula. Perhaps they can take some trees with them and deliver them in Canada after they have sailed through the Northwest Passage. They have encountered the first ice floes (from a distance) in the Kara Sea.

Lucia at the Blackboard has reported the results for her July NH Sea Ice betting pool. No new betting pool for August as of yet.

Comments

[Patrice Pustavrh]

Hi Neven. First, I'd like to congratulate on your nice, well documented effort. But on the other hand, I have a question about weather charts and their correlation to ice movement. Since it is known, that areas of low presure circulate air in anti clock-wise direction and areas of high pressure do this just opposite, could these images be useful for ice displacement prediction ?

[Neven]

Patrice, welcome.

I'm no expert, far from it, but yes, I believe sea level pressure systems are elemental for ice displacement. I'm sure that PIPS or AARI (unfortunately still down and not answering my mails) ice displacement forecasts are based primarily on such weather forecasts as described in this SIE update.

But there has to be a stable situation for circulations like the Beaufort Gyre to get going. Perhaps we will see it again if that high pressure area forms over the Beaufort Sea.

Of course, as ice gets thinner, it can be moved around more easily and is thus more susceptible to winds caused by cyclones and anti-cyclones.

Other people probably know more about this, so feel free to weigh in.

[Kevin McKinney]

Color me crazy, Neven, but I'm not so sure about the decline in melt rate throughout the month, since the measure in question is actually extent.

Surely the volume melting will decrease as daylight hours shorten--but with concentrations relatively low, I wonder if extent may continue to decline relatively quickly for a bit longer? I guess my imagination "thinks" that the extent/area ratio is due to "normalize" a bit, as the season winds down.

A muddled comment, I'm afraid, but perhaps you see what I'm wondering about.

[Neven]

Kevin, always nice to have you commenting, muddled or not.

Of course in theory the melt rate could remain high, but 2008 had the highest rate, I believe, with over 70K per day. It will be very difficult to top that.

I think - but I'm wrong all the time, so... - that if we get that high pressure cell going over the Beaufort Sea we will see some major compaction and thus a high extent melt rate until all the ice is pushed together (possibly as high as 2008). If the high doesn't get produced, there could still be a extent rate considerable enough to end below 5 million square km, but it will more difficult.

We'll see, day from day.

[Neven]

BTW, the weather models are forecasting the high-pressure area to start a day earlier, on Monday August 9th. ECMWF in particular is expecting the anti-cyclone to be fairly strong, with a SLP of 1035 hPa by this time next week. Exciting.

[Neven]

Things have slowed down again somewhat. Preliminary melt of 67,343 square km reported by IJIS.

[Kevin McKinney]

I haven't checked the various basins on CT, but the Archipelago has been rather cool last couple of days, so that presumably has cut into melt there. (IIRC, there was even some snowfall.)

But that's due to change again, with several very warm sunny days in the forecast for most of the Archipelago.

[siili]

Zhang has updated his forecast based on the PIOMAS model, and he's holding steady at 4.8M(km^2) http://psc.apl.washington.edu/zhang/IDAO/seasonal_outlook.html and since the forcing is historical averages from the latest seven years, and i assume that the forcing this year has been rather week, to keep the estimate, the starting state of the ice must have been worse than he thought before.

[siili]

For a few days i have been following a moving station reporting wind direction on Kölns weather map above the New Siberian islands, and today it arrived at the last obstacle remaining in the northen searoute outside Taimyr, and when i checked the shipstracker it turned out to be Mother Russia herself, the atomic icebreaker.

Maybe this will help the russian yacht which has been held up there for over a week in an attempt to be the first to circumnavigate the arctic in one year, and if the Norse are quick they can follow?

But it seams that both Russia and China are keeping secret about what they are doing in the arctic ocean since neither Yamal with Academic Fedorov out on a 100day exploration nor the Snow Dragon are reporting positions to
http://www.sailwx.info/shiptrack/shiplocations.phtml at least.

[siili]

Sorry to use up the bandwidth with garbage( the commodity, not the band), but on the other side of the mirror, the lead story at the moment is that the find of HMS Investigator demonstrates that in the NWP nothing has changed in 157 years! If only Franklin, McClure & followers would have lived in the twilight zone, things would have been so much easier.

[FrankD]

Just looking at Ron Lindsay's prediction - this has been dropping every month since April, while the error has been tightening:
End of:
April: 5.12 +/-0.42 (R2 = 0.84)
May: 4.44 +/- 0.39 (R2 = 0.84)
June: 3.96 +/- 0.34 (R2 = 0.79)
July: 3.7 +/- 0.3 (R2 = 0.76)

His statistical model is strongly dependent on G0.4 and G1.0 (the area of ice that is <0.4m and <1.0m thick, respectively). Like several of us here, he concludes that while extent improved over July, the ice has significantly thinned. For his model that means a large area vulnerable to melting, export or compression, all of which will drop the final extent.

The key areas for him are:
the Kara Sea - virtually ice free now, when it typically has 250,000 sq km at this time,
the Beaufort Sea - with half the usual ice cover for this time,
and the area in and north of the Canadian Archipelago - which on paper isn't doing too badly, but when you look at the satellite pix is in bad shape, I think.

His prediction has at or around the lowest of the ensemble gathered by SEARCH, and I'm pretty sure will be again when their August report comes out.

[Neven]

Bets are being hedged and the hoi polloi prepared for the eventuality minimum ice extent happens to fall below 5 million square km after all. I have already discussed this with Patrick (Lockerby) at the start of the melting season.

There is a strong correlation between melt rate and article rate on the other side of the mirror. When the ice is doing what they want it to do, ie melt slowly, they limit themselves to weekly updates that shows how right they have been (even though their narrowly focussed analysis rests mostly on PIPS ice thickness figures, DMI temps above 80N and the CT comparison page). Once melt rates pick up, they intersperse their updates with shoddily written and thought out articles questioning the way data is processed etc. The behaviour gets more frantic as the ice melts more heavily.

If extent starts to fall rapidly, we will soon hear about how the Chinese already sailed the NWP in the 15th century. Mark my words. If extent falls below 5 million square km, we will see a seamless transition/retreat towards historical records and 'it's all cyclical, AMO/NAO switch will soon kick in, La Niña will bring more recovery'-blahblah.

[Neven]

Holy mother of God, I didn't expect to be proven right so fast.

[Neven]

There, Patrick says it too. :-p

[logicman]

Some pseudo-skeptics go a step too far:
http://www.science20.com/chatter_box/blog/spitting_graves

btw - your " I didn't expect to be proven right so fast" hyperlink shows rel="nofollow" instead of http= or whatever.

[Neven]

Patrick, I didn't link that properly, and perhaps it's for the best. It was leading to a commenter on a recent 'NWP open-HAHAHA'-article on WUWT, saying:

"Didn’t a Chinese Admiral [+ massive fleet] pass through the North West Passage in the mid 1400′s?"

[FrankD]

Oopsie!

Just noticed that in my posst above, the R2 values for Ron Lindsays predictions are in reverse order. Lindsay examines several variables seperately and then uses whichever has the highest R2 to generate the final prediction. The correct details are:
April: 5.12 +/-0.42 (R2 = 0.76)
May: 4.44 +/- 0.39 (R2 = 0.79)
June: 3.96 +/- 0.34 (R2 = 0.84)
July: 3.7 +/- 0.3 (R2 = 0.84)