June 8th 2013
What the heck, I'm giving it another try (practice makes perfect):
The slow start I reported on in the previous update has continued, but as always in the Arctic there is more than meets the sensor. The slowness shows itself mostly in the area and extent numbers (changing as we speak), and the main culprit is that cyclone that refuses to go away.
I initially said this would be a relatively small cyclone, and even called it the Small Arctic Cyclone of 2013 in one of the two posts I devoted to it since the last ASI update, as a tongue-in-cheek reference to the Great Arctic Cyclone of 2012 (GAC-2012). But you know what? It ain't that small, and what's even more interesting: it just won't go away.
For over two weeks now it's been keeping things colder and cloudier over the central Arctic, but at the same time it's been shaking and stirring the ice, wherever it passes. Not to the point that it makes the ice disappear - this isn't August, most of the ice is still thick enough -, but it is showing how mobile the ice is, ripping holes in the ice pack that close up again once the storm has passed. It reminds me a bit of the 2010 melting season, when large regions with holes showed up in the middle of the ice pack.
So this cyclone is the big news of the melting season so far. Here's the rest.
Sea ice area (SIA)
Cryosphere Today sea ice area data had the trend line of 2013 way above all the others at the end of the month, but it seems that the limit has been reached. After a century break a couple of days ago a very big drop of almost 250K was reported today for June the 6th.
Here's the graph based on the latest data:
2013 is still highest, but my guess is that it won't take long for it to catch up with other years. Catching 2012 requires a bit more than just a steep melt, though. June last year was pretty amazing with 17 century breaks and average daily ice decrease of almost 111K.
Here's the link to my CT SIA spreadsheet.
CT SIA has passed the 10 million km2 mark. This excellent graph made and updated by Jim Pettit shows that it took 13 days to get from 11 to 10 million (2012 needed 12 days), but 23 long days to get from 12 to 11 (2012: 14):
IJIS sea ice extent data hasn't been updated for a couple of days. This happens several times every year, for various reasons. The Arctic is quite cloudy and hazy at the moment, with melt ponding starting on fast ice, so maybe our Japanese friends need some extra time to double-check the data. No problemo.
IJIS also had two big century breaks before we lost contact, resulting in a temporary draw between 2013 and 2012. It's interesting to note the differences between extent and area. These differences have always been there, but could become more pronounced as the ice becomes thinner and more mobile, with melt possibly taking place increasingly in the interior of the ice pack.
Regional SIE and SIA
Regional graph of the week, taken from the Regional Graphs page:
The Arctic Basin (or Central Arctic, as the NSIDC likes to call it) is the graph that features most in this segment of ASI updates, as it's the most important region where the last remaining ice is assumed to be before the Arctic goes ice-free. I'm using it now to show that the trend line has begun dropping, slightly earlier than last year. I'm not sure if the resolution is high enough to capture it, but CT SIA counts those holes within the ice pack, whereas extent products do not.
Sea Level Pressure (SLP)
Now we get to the more interesting bit. ;-)
Here's an animation of Danish Meteorological Institute SLP images for the last two weeks to get an idea of what's been going on:
We see how the cyclone moved over the Central Arctic, shifted towards the American side of the Arctic, lost strength, but then re-intensified and moved back towards the Siberian coast, continuously followed (or pushed?) at the edges by high pressure systems with their clear skies and almost 24/7 insolation.
After two weeks the cyclone is still going strong and according to the 6-day weather forecast by the ECMWF model it's going to stay that way for a while longer (click for a larger version):
'A while longer' is an understatement, as the cyclone is forecasted to stay at least for another week and possibly longer. On top of that we've got a nice little Arctic Dipole set up here, and that means a couple of things:
- The cyclone is going to keep shaking and stirring a large part of the ice pack, as it moves back and forth between the Siberian coast and the Central Arctic
- The high(s) over on the American side of the Arctic are going to provide lots of sunshine to the Canadian Archipelago, melting all the snow and increasing air temperatures; we'll have to see how the ice in the Northwest Passage reacts to that
- Both of these together are creating winds that will start pushing ice out of Fram Strait, especially after a couple of days when the whole train of ice floes gets on the move and gains momentum
It looks like the slow start is now behind us.
Maybe if things heat up some more, the cyclone will finally start to fade, but it looks like it won't go without a fight.
The DMI 80N temp graph is showing a very unusual dip just as overall air temperatures north of 80 degrees latitude are about to reach zero:
On the DMI sea surface temperature anomaly maps the red and orange in the Barentsz Sea have been developing some more compared to two weeks ago. There was some red in the Bering Strait as well, but this has disappeared:
Despite a slow decrease in extent and area in the past two weeks, caused by clouds and cold air temperatures over large parts of the Arctic, the ice is taking a beating from the shifting cyclone and it's not sure yet what the damage from internal bruising will be.
The cyclone itself has grabbed its 15 minutes of fame by refusing to go down. I initially called it the Small Arctic Cyclone of 2013, but fellow-blogger Robertscribbler has already given it a more appropriate name: Persistent Arctic Cyclone of 2013. Rocky Balboa would be a good name too.
With the forecast of an atmospheric set-up that is more conducive to ice melt, compaction and transport, it looks like extent and area numbers are going to drop off the Cliff (as it's called on the Forum). In fact, this seems to have started already.
To repeat the conclusion of my previous ASI update: I feel the Arctic sea ice pack could soon go POP under the right conditions. That would be a good title for the next update.