During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily IJIS sea ice extent (SIE) and Cryosphere Today sea ice area (SIA) numbers, which I compare to data from the 2005-2011 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything that can be of particular interest.
Check out the Arctic Sea Ice Graphs website for
daily updated graphs, maps and live webcam images.
ATTENTION: There are new polls in the right hand bar, closing August 20th.
One is for Cryosphere Today minimum daily sea ice area, the other for NSIDC minimum monthly sea ice extent (the one that is used for the SEARCH SIO projections). More info in this blog post.
August 11th 2012
Another two weeks have passed since the last ASI update, and my, what an exciting two weeks they have been. For me personally, the most exciting period since the inception of this blog. And perhaps the most disconcerting so far.
As I wrote two weeks ago:
For a fast decrease you need a strong high in the 1025-1035 hPa range, preferably over the Beaufort Sea. Or a nice cyclone in the 985-995 hPa range to stir things up and cause some of that flash melting that we love so much on the ASI blog because it looks so awesome.
What we got, was a huge cyclone in the 963 hPa range. If you've missed this mega-storm despite all the news stories in the mainstream media (yes, I'm being sarcastic), you can check out the Arctic storms category and see the day-to-day reports here on the ASI blog. Flash melting usually takes place from one sea ice concentration map to the next. This time it's days in a row and it still isn't over yet.
This highly unusual summer storm has massacred all that weak ice on the Pacific side and even caused a large swathe of ice floes to detach itself from the main ice pack. The Stronghold I wrote about a month ago is no more. Trend lines have dropped precipitously on every single sea ice extent and area graph out there.
What is important to remember, is the large discrepancies between this melting season and that of 2007. The latter had almost perfect weather conditions during almost the entire melting season, with lots of sunshine and compacting winds. 2012 had a reasonably good June, but after that the weather switched and hasn't switched back since. Those ideal weather conditions in 2007 pulled in large amounts of warm water through Bering Strait decimating the ice pack on the Pacific side of the Arctic. If 2012 is pulling anything through Bering Strait, it's cold water. The ideal weather conditions in 2007 pushed out very large amounts of multi-year ice through Fram and Nares Strait. 2012 doesn't come close to it. But still, even before the storm, 2012 was following the 2007 trend line as if the Arctic wasn't cloudy and winds weren't blowing the wrong way.
The fact that 2012 followed 2007 so closely, was the strongest evidence possible that a large part of the ice pack is so thin that it will melt out no matter what the weather conditions. The storm only emphasized this, giving all that thin ice a push into the abyss.
Keep that in mind when you see fake skeptics use this storm to mislead their audience into thinking that the storm, a freakish fluke, is the cause of however this melting season is going to end. Although I think they're going to keep quiet about the Arctic, like they are doing most of the time now. As if the Arctic isn't part of our planet. A part of paramount importance.
Sea ice extent
Ever since the switch from the defunct AMSR-E to WindSat the IJIS SIE graph is acting different than all the other graphs (see this blog post), but the storm has finally pushed the 2012 trend line in first position here as well:
The 2012 trend line is now below all the others, even 2007, for the first time since the start of the melting season. It noted 6 century breaks in the last 8 days, and it's not entirely sure whether it will stop there. We're looking at a very exciting end to the melting season with this graph.
The current difference between 2012 and other years (without the unrealistic last data point that gets revised upwards) is as follows:
- 2005: -1,203K (-63,594)
- 2006: -1,181K (-55,406)
- 2007: -120K (-84,750)
- 2008: -936K (-85,969)
- 2009: -1,078K (-46,953)
- 2010: -866K (-64,844)
- 2011: -552K (-60,000)
Between brackets is the average daily SIE decrease for the first 10 days of August. 2012's average daily SIE decrease for those first 10 days is -109,125 km2 per day, which is simply stunning.
Sea Ice Area (SIA)
Cryosphere Today sea ice area data have been absolutely mind-numbing (sorry for all those adjectives, but I think everyone who watches the ice on a daily basis will agree):
Still very much in the lead, more so than ever, rapidly approaching record territory. Which, naturally, means that the anomaly is incredibly low as well:This graph from Larry Hamilton shows the difference with the 2007 and 2011 anomalies:
I don't think the 2007 anomaly record of -2.634 million square kilometres is going to make it until the end of this year. 2012 is bound to go under it, either this month or during the re-freeze period in September and October.
The current difference between 2012 and the other years is as follows:
- 2005: -1,415K (-65,335)
- 2006: -1,532K (-30,894)
- 2007: -618K (-55,315)
- 2008: -814K (-73,417)
- 2009: -1,205K (-50,357)
- 2010: -941K (-41,443)
- 2011: -566K (-51,660)
Between brackets is the average daily area decrease for the first 9 days of August. 2012's average daily area decrease for those 9 days is -84,458 square km per day. That's just insane for this time of the year. 2012 needs to drop just a little bit more than 250 thousand square km to clinch the record.
Cryosphere Today area per IJIS extent (CAPIE)
The CAPIE record has already been broken this year, right before the Arctic summer storm came along. See this blog post for everything you want to know about this type of measurements that tells us something about the compactness of the ice pack.
CAPIE is still very low, which means that the pack is still very diverged (read: there are a lot of holes in the pack), which means there is still a lot of compaction potential. In spite of the storm.
Percentages for August 9th:
- 2005: 70.67%
- 2006: 70.64%
- 2007: 61.84%
- 2008: 66.75%
- 2009: 64.66%
- 2010: 66.78%
- 2011: 61.66%
- 2012: 57.26%
Regional SIE and SIA
Yes, again, the Arctic Basin (or Central Arctic as it is called for MASIE) is the regional graph of the week. That's because all other regions, except for the Greenland Sea and the Canadian Archipelago, are free of ice. The trend line on the sea ice area graph above has dropped below 2.5 million square km, an event that hasn't happened in the satellite era before 2007, but since then has occured every year, except for 2009 (see the historical chart). We have speculated often on this blog about this 'plateau'. The question is how much this year is going to go below this 2.5 million square km mark.
Sea Level Pressure
In the Arctic summer storm updates I showed daily updated animations of SLP images from the Danish Meteorological Institute. Here's an animation of the past week that shows the birth of the storm and its slow demise:
I've said everything there is to say with regards to this storm, so let's have a look at the ECMWF forecast for the coming 6 days:
The next three days a high is moving over the Beaufort Sea. This is a very important set-up, especially during the latter part of the melting season, as it gets the Beaufort Gyre spinning, and that keeps the decline continuing steadily by compacting the ice pack and pushing warmer water towards the edge of the ice pack. It is exactly the thing that made 2007 such an exceptional melting season with an exceptionally late minimum.
The latter three days of this forecast, however, show the high being pushed out again by lows, so I'm doubtful it will have much time to get that Beaufort Gyre going. If the forecast changes its tune and the high gets to stay with a low forming over Siberia (also known as a Dipole Anomaly), it's almost certain that all the records on all the graphs from all data sets are going to be broken (last year it was fifty-fifty). But we're not quite there yet.
Things are looking relatively warm over the East Siberian Sea, the Canadian Archipelago and the Greenland Sea, just the places where we don't want any anomalously warm temperatures:
When it comes to sea surface temperature anomalies (as calculated by DMI), things look more or less the same as two weeks ago (ie very bad), with the red expanding towards the East Siberian Sea:
This is very bad news for the re-freeze period. All those waters are going to have to release their heat to the colder air so that they can freeze over. One wonders what all that heat and moisture in the atmosphere will do.
The storm did a lot of damage to ice that was probably going to melt out anyway. It's not entirely sure what the after-effects will mean for the remainder of the melting season, but it is looking increasingly likely that we are going to see new records, perhaps even new records on all graphs of all data sets. Especially if the Arctic is going to get some of that weather 2007 enjoyed all of its melting season.
First we await that, and then we'll speculate on the consequences for coming melting seasons. But remember: nothing in the Arctic is a dead certainty. This might comfort some people. It scares the hell out of me, if I let it.
Let's hope we see a major slowdown now. I like records to be broken, I want the world to realize the seriousness of events in the Arctic, but things are going too fast right now.