Sea ice extent update 12: taking it slow

I'll be 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 JAXA 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 nice explanation of what sea ice extent is in their FAQ.

July 5th 2010

2010 seemed to be recovering a bit from the blows that 2007 has been handing out for about a week now. Okay, I'm exaggerating here, trying to turn the horse race into a boxing match as well. But seriously, 2010 seemed to pick itself from the floor a bit yesterday, with a provisional melt number that wasn't great, but seemed decent enough. Not much was left of it however after a huge downwards revision of 27K, and 2010 had yet again the lowest reported melt of the 2006-2009 period: 47,656 square km.

Although today's reported melt number of 82,969 square km was slightly better, it was still the lowest, as all other years had century breaks for yesterday's date. And so 2010's lead has had another two bites taken out of it. 2007 and the rest of the pack are on the hunt and smelling blood, as the expression goes in the Netherlands.

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

• 2006: -372K

• 2007: -201K

• 2008: -842K

• 2009: -766K

And here's the IJIS graph:

The Sea Ice Area graph on Cryosphere Today showed a small decrease yesterday but the anomaly has become smaller yet, diving below 1.6 million square km compared to the 1979-2008 mean:

 

The Arctic Oscillation is slowly turning positive and this could have an effect on the Beaufort Gyre, the reversal of which is probably an important factor in the recent slowing of the melt rate:

 

One of the things I reported in the last SIE update was that there was a clear up-tick in the sea ice area of some Arctic regions on the Siberian side, probably caused of course by that reversal of the Beaufort Gyre. It looks as though the trend is dropping again on the CT graphs, as can be seen for instance in the East Siberian Sea, which still has quite a bit of ice left to melt:

However, the biggest region of all, the Arctic Basin, is still showing a lack of melt:

 

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

Patrick Lockerby has written his 4th instalment of MODIS Rapidfire For Citizen Scientists, with loads of interesting information, as always. Another recent piece I haven't linked to yet is Understanding Ice.

SkepticalScience's John Cook meanwhile has written the piece I would write if I knew how to in the second part of his Review of Factors Contributing to the Recent Decline in Arctic Ice. Lots of neat graphs and references. I'm jealous. Correction: the piece was written by Peter Hogarth.

From the Fairbanks Daily News-Miner: Repeat photography book reveals changes in Arctic landscape. Here you can see some of the pictures.

At the Blackboard Lucia has posted the results for the June sea ice bet. Go and collect your quatloos.

Here is a great Scientific American blog post, describing what scientists like Don Perovich (featured in the Youtube movie in the recent Ice Albedo blog post) are actually doing in the Arctic during these months.

And finally, Noiv updated his Arctic Mosaic animation and added the last 10 days to it:

Comments

[Andrew Xnn]

Appreciate the horse race analogy, but I'm tring to understand the relative gains and losses of the anamoly. Has the Arctic oscillation consistently correlated very well or might it be just a coincidence this time? Looks like last year the Arctic basin took a series of saw teeth steps towards a bottom that occured in mid september.

When we talk about an ice free Arctic, I think what we are really talking about is a negative anomaly of about 3 Mkm^2 in the main basis. Right now we are at about - 0.5 Mkm^2, which is about 0.5 Mkm^2 ahead of last year. So, this year we might see - 1.0 Mkm^2 by Sept if the saw tooth step pattern repeats itself.

Off topic; I'm a big fan of the Tour de France. Looked like over million fans are out watching it in the Netherlands/Belgium. Wow!

[Neven]

Andrew, I think I'll need a few more weeks (probably more) before I have a bit of a grasp of the interplay of all the factors that influence the Arctic sea ice melt and growth. Maybe someone else can give a better answer, and you can also read John Cook's piece I've linked to under TIPS.

I believe there is a correlation between the Arctic Oscillation and the Beaufort Gyre, according to this paper I have just read and have to read 2-3 more times before understanding it. And in the past decades it has become an increasingly regular feature during Arctic summer for the Beaufort Gyre to stall or reverse.

It is the only reason I can think of at the moment for the slower melt rate, because it coincides so well. We'll see if the AO becomes more positive and the Beaufort Gyre starts turning clockwise again whether the melt rate goes up again. If it doesn't the ice in the Arctic Basin must be really thick like some people maintain.

But for now, I'll stand by what I've said from the start: If weather conditions approach that of 2007 there will be a new record low sea ice extent. I'm not sure if 2007 saw the weather conditions we are seeing now, and if it did, for how long. I don't think it did, as I recall it the 2007 summer was dominated by clear skies and a constant southern wind.

[Evilreductionist.blogspot.com]

Neven,

The fact that 2010 is still two days ahead of 2007 after the amazing run of 119688, 112968,143282, 162031, 201875 and 130937 is to me an indication that 2010 still has a pretty good chance of beating 2007 to the record. While there are certainly some big days to come for 2007 and some nice runs, all that 2010 needs to do is to average 75,000 a day for the next 60 days and that is the record. This is obviously still a tough thing to do, but it is well within reach.

[Neven]

I agree, Evilreductionist, but I have to spice up these updates, you know? :-)

[Lord Soth]

2007 will be taking a break with no century breaks for five days. This may allow 2010 to maintain or widen its lead, depending on the weather.

[Evilreductionist.blogspot.com]

A century break is the provisional figure for today: 111,563. Based on recent revisions, this is unlikely to remain a century break, however.

[Kevin McKinney]

You scooped me, "evil!"

I'll go with the theory that 2010 is "due" a small or even downward revision this time, and predict that this century break will hold up.

No reason whatsoever--hey, it's a horserace, metaphorically at least, and it's more fun if you cheer sometimes.

BTW, I read on CBC.ca today a denialist comment that "there is no sign of the Arctic sea ice doing anything unusual so far." (As best as I can recall to paraphrase.)

Yeah, right. . . . needless to say, I demurred forcefully. But I thought the idea might amuse. . .

[Artful Dodger]

ER said: "2010 needs to average 75,000 a day for the next 60 days and that is the record"

The 30-day running avg "delta-extent" is currently -77,732 km^2 / day. The 60 Day running average is -70,097 so we do indeed have a horse race.

Unfortunately the Jockey fell off the horse back in the '70s.

[Evilreductionist.blogspot.com]

In fact, I miscalculated - 70,000 per day for 60 days would be sufficient. However, the 60 days takes us to early September now, and those early September days will struggle to get close to 70,000. But the average overall is the key, of course.

[Neven]

11,563 isn't bad, but let's wait and see what the revision does to it.

[Account Deleted]

There are some hot temps in the east Sib and Laptev sea regions - close to 30 degrees C according to the Uni Cologne site http://www.meteo.uni-koeln.de/meteo.php?show=En_We_We

Also PIPS is suggesting ice export into the Greenland and Ckuckchi seas - so we should see 2010 picking up again

[Lord Soth]

I have been looking at the Canadian Southern arctic archepello and there is a lot of ice fog, which forms this time of year. That ice fog is masking the open water between the ice pans. I wonder if this is artificially bringing down the numbers.

[andrewt]

The port of Tiksi apparently recorded a max of 27 today - as Uni Cologne suggested - should be some surface melt around the New Siberian islands.

[Andrew Borst]

SST arctic anomalies. Select anomaly and loop thru the last few weeks. +5C anomalies show up and grow (like 2007 from what I have read).

http://ocean.dmi.dk/arctic/satellite/index.uk.php

[fredt34]

There was such a big rebounce in 2007, too, see http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg ... but it was much later in the season.

[Lord Soth]

After revision we got a 99.5K melt for July 5. Since IJIS does two day averaging also, it was technically a century melt, before it got averaged down.

[Gas Glo]

The 7 day average is now just 65937, lower than 2003 and 2005 onwards.

There are 70 days left to 15 September 2010. Assuming a linear reduction in extent as seems to consistently happen per my graphs then the reduction in extent will be
.5 * 70 * 65937 = 2,307,795 km^2

Current extent 8,446,094 - 2,307,795 = 6,138,299 km^2

When are you alarmists going to realise the ice is recovering?

Err, no, I don't really think that either. I do think this area of a triangle makes more sense for suggesting rate needed to reach minimum extent x rather than the above constant rate of extent reduction. Anyway, that was just the lead up to asking:

What do you think the peak rate of extent reduction will be and when will it occur?

[Neven]

Hmmm, Uni Bremen's daily AMSR-E sea ice maps page seems to be down.