During the melting season 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 2005-2010. NSIDC has a good explanation of what sea ice extent is in their FAQ. I also look at other things like sea ice area, concentration, volume, temperature and weather forecasts, anything that can be of particular interest. Check out the Arctic sea ice graphs webpage for daily updated graphs, maps and live webcam images.
August 20th 2011
Switching weather patterns slowed down the sea ice decrease, as they often do. I must admit I was expecting a bit more after the massive drop in sea ice extent of 127K (the second highest daily drop IJIS recorded during August) last week. I was also expecting CAPIE to go up again (after it hit a record low percentage on August 12th), but because extent would catch up, not because area would shoot up by more than 100K in two days.
On the other hand, despite adverse weather patterns, this year has managed to nibble away at 2007's lead and halved it in 10 days time. This of course says something about the state of the ice, which is so weak it melts anyhow or easily gets compacted in specific areas (see the latest animation). Perhaps not this year, but we are approaching a time when weather patterns will no longer be able to prevent extent and area numbers to drop through the floor.
To repeat what I wrote on August 9th: "If 2011 manages to get within 150K of 2007 by August 20th, the race is on again." I don't think this will become about, as the difference is 250K with only one day to go. It's now very probable that the 2007 minimum extent will remain the record. At the same time the combination of slush puppie ice and relatively high sea surface temperatures make it difficult to rule anything out, as we enter the final weeks of the melting season.
Nothing in the Arctic is a dead certainty.
Sea ice extent (SIE)
Here's the current IJIS SIE graph:
As said, 2007's lead has been almost halved from 470K to 251K from August 9th to 19th. Except for 2008 which had a very big extent decrease in August, 2011 has managed to increase its lead over other years. Barring a really early end to the melting season, this year is bound to end up somewhere in the top 3.
The current difference between 2011 and the other years is as follows:
- 2005: -608K (-45,000)
- 2006: -813K (-37,697)
- 2007: +251K (-57,041)
- 2008: -391K (-70,333)
- 2009: -598K (-48,654)
- 2010: -383K (-51,736)
Between brackets is the average daily extent decrease for the month of August. 2011's average daily extent decrease for August is currently -62,508 square kilometers.
If 2011 loses as much sea ice extent as...
- 2005 did after this date it will bottom out at 4.71 million square km
- 2006 did after this date it will bottom out at 4.96 million square km
- 2007 did after this date it will bottom out at 4.51 million square km
- 2008 did after this date it will bottom out at 4.32 million square km
- 2009 did after this date it will bottom out at 4.65 million square km
- 2010 did after this date it will bottom out at 4.43 million square km
Sea ice area (SIA)
After a massive drop of more than 200K square km Cryosphere Today sea ice area basically hasn't moved for 6 days now, with increases and decreases alternating. Consequently, 2011 has relinquished its number 1 position and is now 174K square km behind 2007. On this graph made and updated by Larry Hamilton we can see how close this year is to equalling 2007, 2008 and 2010:
What with the increases in the past days, the Cryosphere Today SIA anomaly graph has gone up a bit again:
When it comes to the Regional Graphs it looks like the Arctic Basin and Canadian Archipelago have reached last year's minimum with a few weeks left to go. Because of massive divergence of slushy ice in the East Siberian Sea SIA is still higher there than last year, which makes it a key area for potential new records. The same goes to a lesser extent for the Greenland Sea, which is also has a relatively high SIE and SIA because of very slow ice transport through Fram Strait.
Cryosphere Today area per IJIS extent (CAPIE)
This year's trend line has gone up a bit again due to the SIA increases, but is still relatively low for this time of the year, meaning there is a lot of compaction potential, should weather patterns choose to push the ice pack together:
Sea Level Pressure (SLP)
Unfortunately last week's distribution of sea level pressure areas didn't remain stable for a few days longer, as it would have been interesting to see what it would have done to area and extent numbers. Right now, highs and lows are in exactly the wrong opposing spots for sea ice decrease. Of course, cloudy conditions now retain heat as the sun is setting earlier every day and air temperatures start dropping below freezing. But in this final phase of the melting season it's ice displacement and compaction that determine the numbers. As much as the ice allows it of course.
Here's an animation of SLP images from the DMI Centre for Ocean and Ice of the past week:
We see how that huge high quickly dissipated and disappeared altogether, with a new high appearing north of Scandinavia. There hasn't been measured any particularly low sea level pressure in the Arctic this past week, so no really big cyclones to shred the ice pack to pieces.
The Arctic Oscillation Index has been quite negative and is now moving back up again. The forecast ensemble is showing neutral conditions for the coming two weeks. According to the ECMWF weather forecast maps the highs and lows remain as they are, which means we won't be seeing any increased SIE and SIA decreases the coming week:
The highs are going to take over the entire Atlantic side of the Arctic and extend over Greenland. This will prevent any meaningful ice transport through Fram Strait. No big cyclones are to be expected yet either, so the slush puppie ice is spared for now.
Mind you, the ECMWF forecast maps change quite radically from one update to the next, meaning it's not entirely clear what is going to happen exactly. We'll have to watch it on a day-to-day basis.
Update conclusion
Anything is always possible, but it will be difficult for this year's melting season to go below the 2007 record minimum extent. Another 10 days or so and we'll have to start pricking up our ears to see if we hear a certain lady with a certain BMI index is clearing her throat. If the diva takes her time, 2011 will certainly go below 2010 and thus secure a top 3 spot.
There's a lot of melting and compaction potential, but the key question as always is whether time and weather conditions will permit full use of it. That's a lousy conclusion, but all I can do for now. :-)
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TIPS - Other blog posts and news articles concerning the Arctic and its ice:
Canada is flexing its military muscle, much to the delight of Russia and weapon manufacturers all around the world.
Preliminary Bremen map is out.
As noted by Frivolousz21, a lot of ice reappeared in the Beaufort. Since the location of the new ice is nearby where ice floes "melted out" a couple of days ago, it appears there was some consolidation and refreeze of the melt ponds, or shallow ice shelves that were just underwater. However, there are large areas of ice less than 70% (green) now in the Beaufort, interlaced with 70-80% ice (yellow). Over 80% of the ice below 77-78N will melt out this season, and that is over 300k sq km. Some of this ice will be replaced from the central Arctic, if the Beaufort gyre restarts.
The E. Siberian region continues its steady melt. About 300k sq km sit below 80N, and about 250k of that should melt out, with no replacement.
The ice on the eastside is still trying to move about 15-20 km per day toward Eurasia, with limited success, as most of the ice edge melts out. Over the last 4-5 days the ice pack shifted about 60 km in this direction, but in many places the edge barely moved. Ice is moving toward the Fram at a pretty slow rate, and melting out most of the move.
With the movement of the main pack toward the Fram, the hole forming in the pack in the 105E-135E quadrangles is now shifting partly into the 90-105E quad. The hole was squeezed a bit the last two days, but now seems to opening back up again. As the hole shifts, the pack edge toward the Laptev should open up a big gap, allowing seawater from the Laptev to penetrate to 85N, if given favorable wind direction (as currently evidenced by the most recent pack movement. We should see easily 150k sq km loss of extent in the quads around this hole before the end of the season.
Given some loss of extent elsewhere, I expect over 600k loss from the current extent this year. Since my analysis indicates the current extent is less than 4.80 million, this should give us a record low ice extent at the minimum.
Posted by: Paul Klemencic | August 27, 2011 at 20:09
It is simply a soft ware error, it is also shown as far south as the Baltic Sea, where it is +/- 20 celcius (water temp)
Regards Espen
Posted by: Espen | August 27, 2011 at 20:20
Mes ami(e)s, I have just posted SIE 2011 update 18: ten yard line. If you would be so kind as to take the discussion there, merci. :-)
Posted by: Neven | August 27, 2011 at 20:20
The MASIE regional maps have been updated and stamped August 26. I compared the E. Siberian regional map with the old Bremen maps, and found the August 16 Bremen map shows the closest comparison. The reported extent for the Beaufort region on the MASIE map is 605k, and this is consistent with the ice pack shown in the region. The total of all the regional data, is given on the MASIE main page as 5.1 million. yesterday, the extent was given as 5.2 million.
Since the regional maps are ten days old, this the MASIE estimated ice extent of 5.1 to 5.2 million is for August 16!!!
We can predict the future now (note predict, not 'forecast'). The Bremen extent is about 4.80 on August 24 (thanks to Hamilton's comment earlier). The big Flash Melt happened on the 22nd. So we are likely to get small movements down in the MASIE reported number until September 1, then a 100+k drop on the MASIE report stamped September 1. The regional maps should match the August 22nd Bremen map.
Then September 3 stamped MASIE report will likely show 4.8 million extent, consistent with the August 24 Bremen report.
We can watch these events unfold, and compare.
Posted by: Paul Klemencic | August 27, 2011 at 20:32
My last comment on this thread, then I move.
Lucia, read my comments in the thread above about access to Bremen data, then look for Hamilton response. I don't have time to re-type all this for you.
Posted by: Paul Klemencic | August 27, 2011 at 20:37
People always wonder about differences between data sets. Well, Paul went and thoroughly looked into it.
Excellent stuff, Paul. Let's see how it pans out.
Posted by: Neven | August 27, 2011 at 20:38
Paul
All I asked was
I wouldn't have thought the answer required a lot of typing more than "Yes. Brenem posts numerical values" or "No. Bremen doesn't. I read off graphs".
I guess I'll look through your zillions of comments and see if I can find the answer. Then, I'll probably ask someone else!
Posted by: Lucia (The Blackboard) | August 27, 2011 at 22:09
Lucia, I put a lot of time and investigative time into my comments.
You want the simple answer: No, the Bremen numbers aren't available all the time, but one commenter here who knows what he is talking about, has access to the data, and shares occasionally.
But you are really out in the corn field on this one. You are busily crunching numbers with no idea of what they mean, how they were measured, how they relate to the physical system, or even when the measurement was taken. YOU should read every comment of mine on this thread, starting from the top. When you find the comment that starts, "OK guys, if I am wrong on this, I am going to look like an idiot." you should really start reading carefully.
You could learn a lot of how a real skeptic works, instead of a fake skeptic. I am not afraid to admit I am wrong, and correct my mistakes. Real skeptics MUST have this attitude to be effective.
Posted by: Paul Klemencic | August 27, 2011 at 22:47
Paul--
You want the simple answer: No, the Bremen numbers aren't available all the time,...
That's what I wanted to know. I did go back and read to find the information I was interested in. Thanks.
Posted by: Lucia (The Blackboard) | August 28, 2011 at 01:58