Towards the end of last melting season we had a lot of fun speculating about large patches of ice getting separated from the main pack. Well, at least I did. So much so that I wrote an article about it, called Breaking away from the pack. Much of the ice seemed to be very thin at the time and there was so much divergence that a bit of consistent freak weather ought to have been enough to blow away a patch. It didn't come about in the end, but was educative nonetheless.
I was reminded of this as we witnessed two things in the past few weeks. The first was that the ice south of the narrow Bering Strait seemed to get cut off from the ice in the Chukchi Sea. The other was a huge polynya forming north of Franz Josef Land (a group of islands more or less halfway between Svalbard and Severnaya Zemlya) that seems to extend towards Svalbard, cutting off all the ice south of it. A very important factor in this is the upwelling of warm water from the West Spitsbergen Current.
The large patches of blue water can easily be discerned through the clouds on yesterday's MODIS satellite image:
To prevent my becoming a prisoner of premature spouting of speculations I decided to have a look at previous years, using the University of Bremen's excellent archive of sea ice concentration maps. Let's see how peculiar these dark blue holes really are:
As we can see, the hole north of Franz Josef Land is a pretty normal feature, at least in the past 8 years. 2010 had one more to to the west of Franz Josef Land, 2004 has a few holes, and 2006 looks quite spectacular, with a hole the size of Mick Jagger's mouth. Of course 2006 had lowest extent and area around this date, so it's no surprise to see how far the ice pack had already retreated by this time, with Svalbard and some left-over ice surrounded by open water.
This year's ice looks a bit less concentrated than previous years, with a lot of pink (approximately 90%) and even some yellow (75%) in all of the ice south of the line between Svalbard and Franz Josef Land. In the lower right corner we can also see some of the action in the Kara Sea off the Siberian coast, which seems to be ahead of other years. One minor thing of interest is that according to the PIPS 2.0 sea ice thickness model the ice just north of Svalbard should be close to 5 meters thick, but I see mostly open water there. We'll get back to this one some other time.
Bering Strait
Now let's have a look at the current situation in Bering Strait, compared to previous years. By the way, I have covered this area almost two months back (my, how time melts):
2011 is a few steps ahead of the most recent years 2008-2010 and 2006. In 2004 and 2005 the Bering Sea seems to contain less ice, but there are still some substantial patches of ice left in the Gulf of Anadyr. 2007 has some ice left over there as well, but the shape of the rest of the ice resembles the shape of this year's ice, so far.
To top the whole thing off, I have a sneak preview of how other years looked at the end of the month, so we get an inkling of what's ahead:
I'll fill in the last image for 2011 three weeks from now and look at SST in the Bering Strait.
Another excellent analysis. Two things that stood out for me:
"To prevent my becoming a prisoner of premature spouting of speculations..."
Yep, I'm often guilty of that...
And you also said:
"One minor thing of interest is that according to the PIPS 2.0 sea ice thickness model the ice just north of Svalbard should be close to 5 meters thick, but I see mostly open water there. We'll get back to this one some other time."
Not meaning to steal your thunder on this one at all, but of course, it's well known that I think PIPS 2.0 is crap. There I said it...and I feel so much better.
Posted by: R. Gates | May 08, 2011 at 20:39
Yep, I'm often guilty of that...
At the end of this month I'll have a full year of Arctic gazing under my belt, and that should hopefully be remedy some of the jumping to conclusions. But the annual melting of the ice pack in the Arctic is a fantastic spectacle to behold, even without the downward trend.
Nevertheless, there is a chance that sooner or later we will be seeing something spectacular, such as the huge calving off Petermann Glacier last year. And I'm mainly thinking of the disintegration of the ice pack into several big patches, like I've alluded to at the start of this blog post.
Not meaning to steal your thunder on this one at all, but of course, it's well known that I think PIPS 2.0 is crap. There I said it...and I feel so much better.
Well, if you absolutely have to steal my thunder, you might as well do it like that. :-)
Posted by: Neven | May 09, 2011 at 00:10
I just noticed that PIOMAS has released another update. It's getting down to -9K or so....
Posted by: Bfraser | May 09, 2011 at 06:03
I will be surprised to see ice in the Hudson Bay survive to July.
Posted by: dorlomin | May 09, 2011 at 14:35
Thanks for the heads up Bill.
Granted that its a fairly nugatory exercise if hard data is being obtained from Dr Zhang's team, but I have calculated an updated dataset interpolated from the published graph, posted here: http://snipt.org/xwgn
By my reckoning, maximum anomaly for April is -9162, average is -8895. Average for the year to date (four months) is -8736, almost exactly 1000 km^3 below last years figures for the same period.
All four months have been lower that the linear trend, but also lower than the quadratic trend that started me off on this exercise. That is, ice loss is not only accelerating, but it is doing a good impression of accelerating at an ever faster rate.
Posted by: FrankD | May 09, 2011 at 14:51
What do you make of the past weeks increase in chlorophyll in the Barents Sea?
Posted by: Glacierchange.wordpress.com | May 09, 2011 at 17:02
Re: Chlorophyll in the Barents Sea
This is not at all surprising considering the close association of melting ice and chlorophyll blooms. The release of fresh water encourages the chlorophyll growth.
See:
http://www.earthtimes.org/climate/melting-icebergs-linked-carbon-dioxide-absorption/603/
http://www.biogeosciences.net/8/515/2011/bg-8-515-2011.pdf
Posted by: R. Gates | May 09, 2011 at 17:41
That is true but it is the speed of the spread that I was commenting on and its potential association with the upwelling from the WSC
Posted by: Glacierchange.wordpress.com | May 09, 2011 at 18:16
Thanks, Frank. I've updated the link to your interpolated dataset on the Arctic sea ice graph page.
Mauri, I wasn't aware of those chlorophyll blooms. Thanks for that link, those are some great looking graphs. Too bad I don't know how to interpret them (yet). Are these blooms early for the time of the year, or more widespread than usual?
Posted by: Neven | May 09, 2011 at 18:24
I see some blooming here off the coast of Norway.
Posted by: Neven | May 09, 2011 at 18:41
Now that Mauri mentioned it; I noticed the algae this evening, eyeballing MODIS, at the south tip of Svalbard. It assured my opinion on rapid melt in the northern Barentz Sea. An area where Neven gets excited on the possible dissection of a large part of the pack. The stuff UniBremen and CT graphs present as 70% covered sure looked like milk around some scattered floes today. Combine that with the SST anomalies supplied by NCEP and you get... a sense why Tamino is getting more urgent by the day (see his post on ‘hell and high water’).
Posted by: Werther | May 09, 2011 at 19:42
Being very speculative but it could be that a warming artic region is likely to see much increased river discharge into the Ocean and will increase biological activity.
Posted by: dorlomin | May 09, 2011 at 20:48
The chlorophyll is behind the 2010 levels and ahead of 2008 and 2009 levels in same region. The data maps do not go back past 2008 for May imagery anyway.
Posted by: Glacierchange.wordpress.com | May 10, 2011 at 00:43
Thanks Frank, Neven, for the update on PIOMAS data. It looks like we are running 1000 km^3 below last year's trend. Last year, there was only 4000 km^3 left over in September (average ice thickness 80cm). In prior years, the volume difference sustains through the melt season, so we may be looking at a 3000 km^3 remaining ice pack in September.
On top of that, area is still some 250 km^2 less than last year, and if that sustains through the melt season, albedo effect may knock out another 500 - 1000 km^3, resulting is ice thickness of less than 50 cm in September.
One may wonder when the point will be reached when the whole thing would just break up into little pieces and melt away in the Actic summer sun....
Also, thanks Neven for posting Frank's spreadsheet again. Just one request : could you (Frank/Neven) possibly update and post the PIOMAS volume graph too ?
http://img543.imageshack.us/img543/2145/piomasmonthlyvolumes.png
This graph is very revealing and visualised the PIOMAS volume estimates better than the spreadsheet IMO.
Posted by: Rob Dekker | May 10, 2011 at 08:09
The extents is not changing to much but there is some amount of melting in the Altantic side of the sea ice at the minute. Going in way past the 85 degree line.
And as for Hudson bay. Blimey. At this rate it may only have a month of ice left in it this summer.
Its normally far too early in a season to say much abotu the year, but we are definently out the blocks and running now.
Posted by: dorlomin | May 10, 2011 at 14:03
Something seems to be wrong with the Cryosphere Today numbers for 9 May 2011. Hudson Bay, Arctic Basin, and the Canadian Archipelago ice extents are showing significant drops.
Posted by: Yazzur | May 10, 2011 at 14:38
Ah, they've been revised now.
Posted by: Yazzur | May 10, 2011 at 17:31
I have to admit that for a minute I thought the graph for Hudson Bay was for real. :-D
Posted by: Neven | May 10, 2011 at 20:13
Rob Dekker said, "One may wonder when the point will be reached when the whole thing would just break up into little pieces and melt away in the Actic summer sun...."
Both CT and MODIS show brutal, brutal leads opening north of Alaska.
I know I've been saying this for years, but I think this might be the year.
Posted by: Rlkittiwake | May 10, 2011 at 23:11
rlkittiwake "I know I've been saying this for years, but I think this might be the year."
I share your perception, but remember that there are still many unknowns. For one, PIOMAS volume data may be off, since calibration has been difficult since ICESAT went off the air last year, and Cryosat is still being calibrated itself. Besides that, weather in the summer has a big influence, and even then, even as little as 50cm sea ice in September may not break up completely. Still, when we look at the volume trends, it seems that with the loss of 1000 km^3 each year, the remaining 4000 km^3 should be gone by 2014 at the latest. So we may not see a total desintegration this year, but it sure looks like the odd are increasing rapidly...
Neven's latest post on ice thickness models shows more info, so maybe we should take the conversation there.
Posted by: Rob Dekker | May 11, 2011 at 08:58
The area Svalbard to Franz Josef is showing a lot of open water and lots of lower concentrations of ice that are surrounded by ice. I wonder if when those melts break through to the open sea we will see a dramatic drop in extent? Also the ice tends to melt along the extent line and am wondering if this open water effectively increases the melt “front” by extended the line of where the ice and open water meet (if you follow).
It certainly piques my curiosity.
Posted by: dorlomin | May 11, 2011 at 18:56
Indeed, dorlomin, I just noticed that MODIS has a very clear view today of the area around Svalbard and FJL. It's almost all open water between the two island groups. Amazing sight.
Posted by: Neven | May 11, 2011 at 19:13
Definently clear melting going on above 85N now.
Posted by: dorlomin | May 12, 2011 at 15:05