Sea ice extent update 24: high in the 60's

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 14th 2010

There has been an unusual amount of days between this SIE update and the last one, not because the melting season is over and the Arctic has recovered and the alarmist fun of proclaiming the end is nigh has been denied me, as everything is still very much open. The ice can still dip below 5 million square km, or - if the weather doesn't cooperate - stay above it.

No, the reason I was off-line for so long, was that I decided to take a few days off because a good friend from the Netherlands was coming over. He had taken some of those herbs from Amsterdam along with him, which explains part of the title. I was contemplating doing some science in the spirit of Carl Sagan, but thought better of it. Instead I watched the movie Contact yesterday, which was written by Sagan. And very good and thought-provoking it was.

So what has happened in the past week in the Arctic? Well, for one, that forecasted high has developed and shifted over to the Canadian Archipelago. It looks like this has brought an end to the spreading out of the ice, with winds blowing in a clockwise fashion and away from the coast. It hasn't brought any serious melting figures as of yet, but the daily reported extent numbers show a relatively stable decrease of around 60K square km per day (which explains the other part of the title).

These are the consecutive daily melts as they were reported by IJIS: 50,313 square km for the 8th, 68,125 square km for the 9th, 60,781 square km for the 10th, 67,969 square km for the 11th, 61,719 square km for the 12th, and today's revised number was 59,531 square km. Except for the 8th of August, all of these melts were second highest for those dates in the period 2006-2010.

What this means is that 2010 is still in second place. It has managed to extend its lead over 2008, 2009 and 2006 since the last SIE update and even nibbled a bit at that tremendous lead 2007 has built up so far. As is known 2008 maintains a pretty hefty rhythm in this period, so it will be interesting to see if 2010 can keep up.

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

• 2006: -373K (37,697)
• 2007: +705K (57,041)
• 2008: -138K (70,333)
• 2009: -235K (48,654)

The average daily melt for the month of August is between brackets. 2010's average daily melt for August is currently 67,031 square km per day.

If 2010 loses as much sea ice extent as...

• 2006 did after this date it will bottom out at 5.41 million square km.
• 2007 did after this date it will bottom out at 4.96 million square km.
• 2008 did after this date it will bottom out at 4.58 million square km.
• 2009 did after this date it will bottom out at 5.01 million square km.

Here's the IJIS sea ice extent graph:

Strangely enough sea ice area has been decreasing at a very slow rate. The trend on the Cryosphere Today sea ice area anomaly graph was holding steady at around 1.5 million square km below the 1979-2008 mean, but has now plummeted back to -1.277 million square km. The sea ice area in the Arctic Basin and the East Siberian Sea has stopped dropping for a while now and has even been going up in the past few days. The same goes for the Laptev Sea and the Canadian Archipelago where multi-year ice from the Arctic Basin has been spilling into its straits and channels. The Kara Sea and the Beaufort Sea seem to have reached their bottom.

 

If we look at the compactness graphs that show the ratio between CT sea ice area and IJIS sea extent (a not so trustworthy, but still interesting indicator of melt ponds and divergence/convergence that lets us compare 2010 to previous years), we see that the slowdown in sea ice area decrease has caused compactness to go up. It was holding steady around 65%, but has gone up in the last day and currently stands at 67.62%.

It remains to be seen whether 2010 will reach a new bottom this month, like 2007 and 2008 did. Have a look at FrankD's latest compactness graph that shows the ratio between IJIS extent data and IJIS area data estimated from the IJIS sea ice area graph and looks quite a bit different.

But enough about the ice, let's talk about the weather.

I have asserted in the last SIE update that 2010 has a last chance for change as the window of the melting season starts to close and temperatures will be going down to the point that sea water between floes will start to refreeze. This last chance is highly dependent on weather patterns that will once again cause transport and convergence of the sea ice, after the 6 week lull during July and the first part of August that spread out the ice all over the Siberian side of the Arctic Basin and in large part prevented ice from flowing out of Fram Strait.

In the blog post Any way the wind blows, preceding the last SIE update, I wrote that a change in atmospheric patterns was forecasted by the ECMWF medium-range weather forecast. What was forecasted has indeed come about and this is, I believe, the reason that the sea ice extent has been dropping by around 60K for the past few days, which is a pretty decent number for this phase of the melting season.

On the daily updated Arctic weather map from the University of Cologne that I have downloaded these past days we can see how a high-pressure system developed over the Beaufort Sea and has been slowly moving towards the Canadian Archipelago:

 

The Arctic Oscillation Index is also showing a very negative AO, indicating that the Arctic is currently dominated by high-pressure systems:

 

So what can we expect? Will 2010's chance to do something remarkable and dip below the 5 million square km mark be extended? This is the ECMWF forecast for the coming 10 days:

 

A serious high-pressure system is expected to stabilize over the Canadian Archipelago, extending itself over Greenland by Tuesday, with sea level pressures reaching 1030 and even 1040 hPa. This should cause some big winds blowing in a clockwise fashion. Speaking of big winds: another thing I've noticed is the forming of a very big low-pressure area over the Kara Sea. This cyclone might wreak havoc and kickstart the Transpolar Drift Stream, enabling the transport of sea ice through Fram Strait. It will also push the last narrow band of ice away from the Siberian coast that is blocking the Northern Sea Route, allowing our Norwegian friends Børge Ousland and Thorleif Thorleifsson to push forward towards the Northwest Passage that should also be officially announced to be ice-free and navigable soon.

PIPS is showing ever bigger ice displacement arrows pointing in a clockwise fashion. I expect this 'circle' of arrows to move more to the right and get that Beaufort Gyre going for real.

 

One would expect sea ice area and extent to keep decreasing, perhaps even faster than in the past week. But with the Arctic sea ice you can never be sure about anything. The ice looks so thin and mobile that it just gets pushed around every which way. With the straits and channels in the Canadian Archipelago opening up for transport there might not even be enough resistance for sea ice to be compacted in a serious way, like Patrick Lockerby says in one of the comment sections.

I don't think I'm exaggerating when I say that we have the most interesting part of the melting season ahead of us.

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

I have updated the animations of Peary + Sverdrup and Adolf Gustaf + Ballantyne. The southward transport of the ice in the Canadian Archipelago is very plain to see. The Northwest Passage seems to be practically ice-free as well.

Patrick Lockerby has released the second update of his Arctic Ice August 2010.

Comments

[Andrew Xnn]

2008 was a leap year, so it and 2004 could 1 day ahead of all the rest
depending on how things are calculated.

However, looking at the average daily melt for the month of August, it
is apparent that August 2008 was an exceptional month too.

[Patrice Pustavrh]

Hi Neven, it is very nice to come to your blog from Ouslund's blog which is indeed interesting blog to watch. I'd like to comment on Patricks correction on my prediction of compactification, because I think we were speaking about two slightly different things. The way wind blows now moves ice from East Siberian Sea towards the centre and further along towards Canadian Archipelago. Of course I was innacurate about serious compactification and Patrick is of course very right that serious compactification cannot occur with this mobility of ice and that we will see a lot of export through that region. However, I think that the a little bit more ice north of Canadian Archipelago and land of course, islands themselves will lead to some sort of compactification. Way below, but I think this will bring the area and extent further down (because ice is thinner than usual while being spread around and area/volume ratio is really low now). Great mobility of ice can bring ice more closely together and with just slight increase in thicknes, which would still be way below normal levels, extent can easily drop to at least 2008 levels. I must admit that I am deliberately not talking about melting. Not because I do not believe that there is no melting or that it is slower like it was in previous years, but just because I am at the present knowledge capable about talking only about ice distribution with reasonable accuracy. And my point is not to feed Watts or Goddard, but just to reveal some variability and that we really need to be careful about interpreting various years results. And finally, if the weather predictions hold for next 14 days, I would not be surprised that extent and area drops will be well above average for this time of year.

[Neven]

2008 was a leap year, so it and 2004 could 1 day ahead of all the rest
depending on how things are calculated.

Andrew, I in fact compare Julian dates. In my spreadsheet I don't use any February 29th, which means 2008 has a day extra at the end of December. So in a way today's date, August 14th, is compared to August 13th 2008. But both are referred to as Julian day 226.

Patrice, I agree. When I say melt I of course mean 'decrease of sea surface covered with ice', whether this occurs due to melt, transport or compaction. Real melt refers to sea ice volume. CryoSat-2 will tell us more about that.

[siili]

Sorry to be a nitpick Neven, but since i am an astronomer, Julian Day is in fact something different http://en.wikipedia.org/wiki/Julian_day, what you are using could perhaps be called day number or formaly last three digits of an ordinal date.

[Neven]

Indeed, siili, thanks for bringing that to my attention.

What I meant was this: August 14 is the 226th day of the year (227th in leap years) in the Gregorian calendar. So I compare this day to the ones in other years. As 2008 was a leap year, August 14th was actually the 227th day of the year. Therefore I compare today with August 13th 2008, which was the 226th day of the year in 2008.

Right, now I have a headache again.

[siili]

If it will cure your headache, you might as well use the Julian calender at least untill 2100 when it matters next time...

[Neven]

Siili, you will have to come up with something better. What will I use after 2100?

[toby]

Thanks for the post, Neven,. I think we are entering an interesting period - almost literally the last quarter. It is hard not see it as a competition and "root" for a side, but when the implications of low extent hit home, I am a bit sickened.

Along with the extreme weather, which has attracted attention worldwide, a low Arctic ice measure might help speed up political action. But how different it was last January when the ice extent was approaching average & a lot of the Northern Hermisphere was having a tough winter The two (last winter & this summer) are not equivalent, however, because a lot of the extreme temperatures and floods have exceeded records, while there were none did last January. I do sense a different tone in the mass media towards climate change, but we know short the attention span is.

[Phil263]

JAXA reports : -60,781 SIE decreae. Just for the anecdote, exactly the same decrease as for 14 Agust 2008 (at least same day in my calendar :)!

[Anu]

It takes a very complicated wind pattern to spread out ice floes to create large lakes surrounded by sea ice (look near the Beaufort and Chukchi Seas):
http://img405.imageshack.us/img405/6646/arclatestlarge201008140.png

But it is trivial to create such lakes by melting - the question is, how thick is the remaining, nearby non-melted sea ice ?

In summer 2008, ice mass balance buoys measured bottom melt and surface melt at various locations around the Arctic:
http://www.joss.ucar.edu/events/2009/aon/reports/richter-menge_jackie.pdf
In the Beaufort Sea, where 3.2-m thick ice completely melted by 23 August 2008, with more than 0.85 m of surface melt and 1.77 m of bottom melt measured, the largest amount of melting was measured. On average, they saw 0.47 meters of surface melt and 0.66 meters of bottom melt that summer - so, on average, the warm water melted more ice than the direct sunlight and warm air.

I suspect that huge sheets of sea ice near those "lakes" are close to "running out of thickness" as the summer melt continues...

[Chartsgraphs.wordpress.com]

It's now 5 straight days of 2010 SIE decrease being > than 2007 values!! 2010 has reduced 2010-2007 gap by 93,300 km^2 in 5 days.

While 2010 - 2007 gap is -676,000 km^2, there are 41 remaining daysl for 2010 to match the 2007 minimum SIE.

Kelly O'Day

[Mike]

If I may mediate on the subject of Julian Date, it does have a different meaning in the computer context as 'ordinal date' as opposed to astronomical usage. While I'm here I'd like also like to comment on the amazing things happening in the Arctic. I can't help but think that the departure of land-fast ice may have immediate consequences for wildlife in general. I think this might be a more immediate problem than general climate change. The East coast of Greenland is really shedding(?) quite rapidly.

[Neven]

CT also reports a decrease of 66K in sea ice area.

Kelly, I really don't think 2010 will catch up with 2007. Staying ahead of 2009 is challenging enough as it is. And perhaps, if those highs and lows do enough damage in the right spots, 2008 can be beaten as well. But that's tops for this year, I think.

[Neven]

After a downward revision yesterday's melt is 63,281 square km. Still in the 60's.

PIPS arrows are looking interesting.

[Phil263]

SIE barely 40k down today... (Jaxa preliminary)

[Phil263]

CT also reports an increase of 9 k in SIA ? I cannot really see where this increase would come from as all areas. seem to be losing ice except for a slight uptick in the arctic basin.
I also note on the uni bremen , map, that the holes North of the Beaufort sea have closed up since yesterday which may explain the small decrease in SIE today (?)

[Neven]

I was expecting a bit more than that. Is that big low between the Kara and Laptev Seas blowing all the ice outward toward Fram Strait?

[siili]

Second that, but looking at the Jaxa timeseries, the Fram outflow is increasing extent, but then looking at the wind and ice bouy drift maps, i don't think the reall move has started yet. From Amundsens measurments the whole southern Beaufort is full of 10 C warm waters, which is starting to move at the ice guided by the increasing high over the CA.

And thinking about the closing whole, MODIS had a very good day yesterday http://rapidfire.sci.gsfc.nasa.gov/subsets/?subset=Arctic_r05c02.2010227.terra

[Phil263]

in his arctic ice august update #2 , Patrick mentions the possibility for ice floes to be partially covered by see water " swamped ice". I was wondering how that "swamped ice" would register on satellite pictures such as AMSR-E. In other words is it possible that "swamped ice" would have missed, and then when it reemerges it would picked up as ice area, which would explain the increase in SIE /SIA?

[Phil263]

For the link to Patrick's article on submerged ice floes try here .

[Phil263]

Have a look at WUWT report on Climate Change day in Australia (That was yesterday). More evidence if any was needed that that site is not about science. In these days of election campaigning, WUWT arcticle actually reads like a conservative ( called "Liberals" in Australia), propaganda piece against climate change action.

[Lord Soth]

Well we broke the 6 millions sq. km. barrier last night. It still subject to revision, but I dont see a 20K correction in the works.

To keep in the running with 2008; we will need to lose another million sq km in 16 days.

It possible, but we can't have very many more days like yesterday.

With only a month left in the melt season; I think PIPS will be on the money with 4.8 million sq km of slush. This is a remarkable accomplsihment despite July being cool and clowdy.

[Kevin McKinney]

"More evidence if any was needed. . ."

None needed as far as I'm concerned. It's a pure propaganda operation, as long since revealed by their "chopping and changing"--that is, the incoherence with which the latest anti-mainstream factoid or crank theory is embraced and celebrated, regardless of how incompatible it may be with yesterday's "theory." (Or with anything else, for that matter.)

They've been corporately calling black "white" over there so long that I doubt there's any remaining ability to distinguish the two.

[FrankD]

Check out the Beaufort Sea on todays MODIS (day 227).

Very little icepack, just a huge area of "milk". Personally, I think CT's extent estimate is generous, for that area at least.

[Lord Soth]

That milk like appearance is caused when the individual chunks of ice are much smaller than the resolution of the imaging. Those flows are probably anywhere from a few meters to few 10 of meters across; and are in the last stage of melting out.

[Phil263]

To keep in the running with 2008; we will need to lose another million sq km in 16 days.
I doubt very much that 2010 is still in the race for a minimum under or even comparable to 2008.
Yes today 2010 SIE is still barely below that of 2008 but it will probably not be after the new update. SIA has been going up over the last three days ( see CT ) and is now almost 400 k greater than 2008. If SIA is predictor of SIE, this means that the melt in the next few weeks is going to be very reduced.
In my view, 2010 will have a big challenge keeping up with 2009; actually it looks more like 2006 than 2009!
I have been reading the posts and comments with great interest as i do not know much about ice science. I have read that the weather has a big influence, but now the weather is favourabble so there must be some other variables. The NSIDC mentioned in its update in early July that there was mo thick ice this year and may be this is the reason why we are seeing such low rates of SIE decrease. I am here to learn and I have learnt a lot from this site, but obvioulsy the science on this is not settled,

[Artful Dodger]

FrankD, the latest Arctic SST map confirms the extent of the sea ice loss in the Beaufort Sea and Central Basin:
http://polar.ncep.noaa.gov/sst/ophi/color_sst_NPS_ophi0.png

[Kevin McKinney]

Welcome back, Dodger.

Phil, don't be too sure yet. If there's anything I've learned about the sea ice, it is that it is very prone to make fools of all of us who dare to traffic in predictions--especially short-term ones! The weather just turned; let's see what happens after a few more days.

[siili]

Jaxas preliminary numbers are in, at 5910781km^2, 70625 less.

Two interesting things could be noted, the history of (two-day averages) losses is about 60k,60k,40k and 70k, and if 60k was the true 3 days ago, 120k should be the unsmooth loss for today.

The other noteworthy thing is that in the preliminary Jaxa-images there is a rather big artifact in the choppy sees of the deep low south of the iceedge which will be corrected in the update later today, if that is counted in the extent number, well...