The season of contrasts continues. The conclusion after the freezing season that the ice on the Atlantic/Siberian side of the Arctic looked vulnerable and the ice on the Pacific/Canadian-Alaskan side of the Arctic should be thicker than usual, is extending itself into the melting season: Whereas the Northern Sea Route could be opening up in record time, the fast ice in the Northwest Passage has still to start breaking up.
We now have four seasons of wonderful satellite images provided to us by the LANCE-MODIS data system, and so we have an animation that allows us to compare this year's situation with that of previous years:
Even though yesterday's image (day 164) is 4-5 days behind the other years, it's as clear as day that this year the NWP is very slow to open up. One partial explanation for the discrepancy with other years so far is air temperature. Take for instance the temperature anomalies for the first three months of the year (source: NOAA daily mean composite page):
2010 was hottest and thus broke up/melted out fastest, followed by 2011. Temps in the NWP in 2009 were mostly non-anomalous, except for Lancaster Sound, where the ice already had begun to break up by now. The first three months of this year temps all over the NWP were non-anomalous, which means it was as cold as the 1981-2010 base period on average. In other words, it was pretty cold and this is probably the main reason the ice is still holding out.
With this info in mind, the big question of course is whether the NWP will become navigable this melting season, as it was in 2007, 2008, 2010 and 2011. This depends on many factors, the most important of which will be weather conditions. But another factor that is not to be underestimated is the amount of multi-year ice in the NWP. The latest SEARCH Sea Ice Outlook has some info on that in the June 2012 Regional Outlook report (hat-tip to Diablobanquisa, who published a blog post on the NWP yesterday):
Figure 1 shows the concentration of multi-year ice (MYI) in the western channel of the Northwest Passage at the end of May this year and for the past four years compared to the 1981-2010 climatology. Howell points out that concentration of MYI in the region is well below the historical average and that it is likely the seasonal first-year ice will clear during the melt season. However, clearing may only be temporary since a large open water area provides a pathway for MYI to transit south from the Queen Elizabeth Islands. The ensemble prediction from the PIOMAS model submitted by Zhang and Lindsay is in agreement and shows a mostly open Northwest Passage (Figure 2a). There is significant uncertainty in both forecasts. Zhang points out that the standard deviation in the model ensemble is high in this area (Figure 2b) and Howell notes that predicting clearing in advance of breakup is difficult due do a number of factors that have to occur in tandem during the melt season.
Figure 1. Spatial distribution of multi-year ice concentration (in tenths) within the Western Parry Channel region of the Northwest Passage at the end of May. The median climatology 1981-2010 is compared with 2007, 2009, 2010, 2011, and 2012. Data is from the Canadian Ice Service (Howell).
Figure 2. (a) Ensemble prediction of September 2012 sea ice thickness in the Northwest Passage region and (b) ensemble standard deviation (SD) (Zhang and Lindsay).
So there's a lot of first-year ice in the NWP this year, more than ever, but the relatively low temperatures during most of the freezing season have probably thickened that FYI up more than in previous years.
With regards to the "large open water area provides a pathway for MYI to transit south from the Queen Elizabeth Islands": it didn't happen in 2010 and 2011, despite a substantial inflow of multi-year ice from the Arctic Basin (see for instance these animations from 2010). Somehow that MYI didn't make it all the way to the NWP, probably because of in-situ melting and transport cut short by the onset of the freezing season. Which is why the MYI concentration shown in figure 1 is so low this year. In principle, yes, transport of MYI from the Arctic Basin should block the NWP, but I haven't seen it yet.
And so it all depends on the weather and the thickness of this first-year ice in the NWP. It was cold there for most of the freezing season, so it's most probably thicker than in previous years, but whether it will be enough to keep the NWP from opening up, remains to be seen. We'll know more in a couple of weeks.
Hi Neven,
Slightly off-topic:
I'd just noticed within the Regional Search Outlooks that, due to low air temps over winter, there is a prediction from some reputable source that the Nares ice bridge will survive until mid-July - much later than in some previous years.
Posted by: idunno | June 13, 2012 at 13:53
It may have been cold this winter in the Canadian Arctic, however the summer tempertures do get quite warm, with 24 hour sunlight over much of the islands in the archipelago.
Practically all the ice in the North West Passage routes, is weak first year ice, and will melt out.
The ice in the Queen Elizabeth Island is five meters thick and 4-5 years old, and if it does break up, it will be very late summer, so it should not float south and block the passage, before it has time to open.
I will eat my shorts, if the main route (McClure Strait, Viscount-Milville-Lancaster Sound) does not open this year.
On another note, according to Cyrosphere Today, sea ice are is at record low for this date, and sea ice extent appears to be very close to a tie for a record low for this date.
Posted by: Lord Soth | June 13, 2012 at 15:30
That's quite surprising isn't it?
You have shown that this is true for the Canadian archipelago, but a look at, for example, thePosted by: Misfratz.wordpress.com | June 13, 2012 at 16:20
I was indeed surprised to see the ice in the Beaufort Sea retreat so easily, but the data from the IceBridge mission (from EM-birds hanging from planes, see graph) shows that the ice isn't exceptionally big there.
All of our hopes seem to rest on the ice in the Canadian Archipelago, and the chunk of MYI in the Arctic Basin. And the weather, of course.
It's going to switch now, so it will be interesting to see what that does to SIE and SIA decrease. No Beaufort Gyre on the one hand, but a big low over the Central Arctic and Beaufort, and a high over Kara/Laptev.
Posted by: Neven | June 13, 2012 at 16:59
These are big thick blocks held in place by first-year glue, but it takes a long time for the melt to progress that far north and often they will not make it very far before getting frozen in again. The channels are mostly more open at the north than the south, so large floes can enter and get stuck between islands for long periods. But when these channels open they can shift quite a bit of ice quite a long way.
For example, in 2010 I followed a large floe that had been locked in east of Byam Martin Island. It had originated several years earlier in the Basin and was so big it had become jammed in the channel until it degraded enough to come loose in 2010. It can be seen in place on day 193. By Day 203 it had broken free into the NWP, and at 800 sq km's was the biggest single chunk of mobile ice in the area. Over the next two months it drifted towards the eastern exits of the NWP and then abruptly reversed course. Some floes that were keeping it company eventually exited the NWP between Banks and Melville (the NW end of the passage) having traversed almost its entire length, but this one got diverted by an eddy and instead ran down the east coast of Victoria Island. It overwintered between Victoria and King William before the combination of the melt and a storm caused it to break up and disperse in late July last year not too far from Cambridge Bay.
Other floes followed it out from the upper archipelago, and were replaced by ice from further north, all ultimately coming from the Arctic Basin. It can take several years - just like Amundsens navigation of the NWP - but absolutely it is an outlet for ice from the basin.
The "problem" is that the channels in the upper archipelago are narrower than the NWP itself, so any ice that makes it through there is too small and loose to entirely block the NWP. But if you look at Melville Island in August last year (Day 213 is pretty clear), most of the ice around the south coast entered the NWP from around Byam Martin Island. You can also see the fracturing in the main channel connecting the Basin and Viscount Melville Sound. Most of this MYI was still in the NWP when the freeze up occurred, and its presence partly accounts for the robust state of the ice currently choking the NWP. But a lot of this is in relatively small pieces and I'd be confident it will shift before the season is out.
Posted by: FrankD | June 13, 2012 at 17:14
The large bite out of Amunsden Gulf yesterday and the high temperatures don't look good for the west end.
The low pressure area over Foxe Basin may do some damage to Lancaster Sound & The Gulf of Boothia in the short term, then on the 22nd a spring tide could play havoc with everything.
I think that by the end of the month we'll see considerable progress opening things up from both ends, possibly more in the southerly route.
Terry
Posted by: Twemoran | June 13, 2012 at 20:39
I was expecting that ice arch in Nares to go before last year's arch. They look very similar, but the ice looked weaker to me up till April 7th, when Envisat stopped sending images. That said, I'm not so sure anymore, despite a bite out of the arch on one end, and a polynya near the other end (which seems to have frozen over again!).
We'll see. I'm checking it out every day now.
Posted by: Neven | June 13, 2012 at 20:43
For some strange reason, Nares, compared to everywhere else up there, looks very strong and solid, and I do not expect anything special in the strait for the rest of this month.
Posted by: Espen Olsen | June 13, 2012 at 20:49
Hi neven,
"I'm checking it out every day now."
Yeah me too, but this guy...
http://www.arcus.org/files/search/sea-ice-outlook/2012/06/pdf/regional/gudmandsen.pdf
...thinks we're wasting our time.
Posted by: idunno | June 13, 2012 at 21:06
Well, if I'm not mistaken, Environment Canada predicted Nares to open up much later last year too.
Posted by: Neven | June 13, 2012 at 21:09
It is right scary how Baffin Bay is opening up in the last few days.
Posted by: Eli Rabett | June 14, 2012 at 00:12
I'd been watching Nares Ice bridge as well expect I hadn't looked for a week or two. Things look like they;ve changed around the bridge a fair bit.
It's been like this since March
http://ocean.dmi.dk/arctic/images/MODIS/Kane/20120524TERR.jpg
Then over the course of a week it turns into this
http://ocean.dmi.dk/arctic/images/MODIS/Kane/20120612TERR.jpg
(more of that blue ice)
Posted by: Pete Williamson | June 14, 2012 at 04:46
Thinking about it I guess that could just be snow melt revealing less homogeneous ice underneath??
Posted by: Pete Williamson | June 14, 2012 at 04:49
That's what you get when there is no ice transport from Nares Strait and Lancaster Sound into Baffin because of stubborn ice bridges. :-)
Posted by: Neven | June 14, 2012 at 08:16
I thought other people might be interested in the OSTIA SST anomalies around the Canadian Archipelago.
This corresponds to absolute temperatures of +1C over a very wide region, so while the air temperatures have been low, there appears to have been an inflow of warm water - assuming we trust OSTIA in this region.
Posted by: Misfratz.wordpress.com | June 14, 2012 at 09:54
On last years Northwest Passage animation I put a link to a sailwx tracker on part of the Ayles ice shelf. If you put the time up at 20000-30000 hours + you can see how it wandered through and out of the passage for the last couple of years. (I did try to link to the picture of the track but it just seems to revert to a link to the sailwx site - can anyone fix it?).
http://sailwx.info/shiptrack/shipposition.phtml?call=47554
Posted by: Mike Constable | June 14, 2012 at 13:39
Anyone else notice that the bridge changed yesterday? The front edge had been somewhat jagged on the satellite image for a while, but yesterday (day 165) it suddenly became quite smooth. I wonder what (if anything) that portends.
I don't have a timeframe (total guess around the end of the month), the Ellesmere end of the bridge will collapse under the combined forces of melt from below, the expanding polynya just above it and the lateral pressure of ice from the two Ellemsere fjords (being slowly pushed forward by glaciers). Now that the snow cover is gone, the rocks and blue ice are soaking up a lot more solar heat.
Posted by: FrankD | June 14, 2012 at 16:26
The full moon tide will do the job in the end of the month.
Posted by: Espen Olsen | June 14, 2012 at 17:23
@FrankD,
I saved 1km Aqua r03c02 images for days 164 and 165 and then subtracted one of the other. There is a 1 - 2 pixel retreat of the bridge from day 164 -> 165 and about 2 - 4 pixels retreat from day 162 -> day 165. I think there is quite a bit of water flow underneath the ice and is either melting or taking some ice away from the edges of the bridge.
Posted by: DrTskoul | June 14, 2012 at 18:22
Dr Tskoul
If you were standing at the edge of that bridge you would probably feel like being next to dam, the current up there is really southward.
Posted by: Espen Olsen | June 14, 2012 at 18:38
Mike Constable, here it is:
Posted by: Neven | June 14, 2012 at 20:31
The arc of ice at the entry of the Lancaster Sound has lost a large block (day 167 ; block that break up today : 168).
The opening of the eastern door of the NWP begins....
Posted by: paoloc | June 16, 2012 at 23:09
Today big break in the Amundsen Gulf (and little in Mc Clure Strait)
Posted by: paoloc | June 17, 2012 at 23:26
Two break (day 164 and today => 6 day) for break up all Amundsen Gulf!!
Posted by: paoloc | June 18, 2012 at 00:17
Is the main CAA route open for service?
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=07&fd=15&fy=2012&sm=08&sd=03&sy=2012
Posted by: Seke Rob | August 06, 2012 at 12:45