On the fringes

2011 is coming to an end, which means we're halfway through the Arctic winter. The sea ice is thickening up nicely everywhere in the Arctic interior, but things aren't progressing as uniformly at the edges. Just like last year we see an above average ice cover in some regions, but a very slow freeze-up in other regions.

A good example of the former is Hudson Bay. It was extremely late in freezing over last year, and thus melted very fast in Spring. This year, however, its ice cover is almost average for the time of year according to the Cryosphere Today regional SIA graph:

The Bering Sea region is above average and will hit its maximum SIA fairly easily in the coming weeks:

But as we so often see in the Arctic, an increase in one part is countered by a decline in another part. The Siberian side of the Arctic is where we see a significant slowdown in ice formation this year. The freeze-up was slow anyhow because of relatively warm waters at the end of the melting season in the Laptev, Kara and Barents Seas. But where the Laptev Sea has frozen up alright, it seems a couple of cyclones in the past weeks have stirred things up enough for large expanses of water to stay open in the Kara and Barents Seas (white demarcations according to the CT division of regions):

This is reflected on the regional SIA graphs, showing some big anomalies:

These Seas will probably reach their maximum ice cover in the months to come, but much of it won't be very thick. We'll have to wait and see what this will mean for the ice retreat on the Siberian side of the Arctic and the Northern Sea Route when the melting season gets underway again.

Meanwhile, as Diablobanquisa reports in last week's blog post Sin hielo en el Báltico (no ice in the Baltic Sea), not too far to the south of the Barents Sea, on the other side of Finland, the Gulf of Bothnia is not showing any signs of freezing yet either:

These maps are provided by the Baltic Sea Portal and show last year's situation (left), this year's situation (middle) and average (= normaali) ice conditions (1965-1986) on the right. 'Jäätä' means ice. This year there's still no ice whatsoever (see MASIE regional map), whereas last year the ice cover was way above average.

As Diablobanquisa explains this has a lot to do with the NAO (Northern Atlantic Oscillation). When the NAO is negative a weak high west of Europe makes for weak winds, lower temperatures and thus more ice. With a positive NAO it's the other way around: stronger high, stronger winds, higher temperatures, less ice.

This image from a paper by Timo Vihmaa and Jari Haapala in Progress In Oceanography illustrates the point:

According to NOAA's Climate Prediction Center the NAO has been and currently is positive:

Three to four months left to go for the ice to stretch out as far as it can.

All the best for 2012!

Comments

[adelady]

Thanks Neven.

Though you should exercise your psychic powers more vigorously. I spent a fair bit of time yesterday looking through a heap of these maps and graphs. If I'd 'received the message' that you were doing the job for me, I could have saved a bit of time.

[crandles]

I think it is noteworthy that the Bering sea has considerable variability from year to year. So while this year is above average, it is below the extent/area seen in some years.

That contrasts to the Kara sea where there is usually little variation. So this year's below normal extent/area is almost certainly a record.

In fact of 2003-2010 it looks like 2005 had least ice in Kara sea and on 5 Dec that looked like

http://iup.physik.uni-bremen.de:8084/amsredata/asi_daygrid_swath/l1a/n6250/2005/dec/asi-n6250-20051205-v5_visual.png

compare current
http://www.iup.uni-bremen.de:8084/ssmis/arctic_SSMIS_visual_small.jpg

It looks to me like we are easily more than 24 days later and still at a record low for 5 Dec in Kara sea.

[idunno]

Hi Neven,

I am struck by the difference between today and 12 months back on the Atlantic side Sea Surface Temps;

This time last year, we had the strong hot anomaly creeping up the West Coast of Greenland, leading to record Surface Air Temps in WEst Greenland and over in Labrador in Canada.

This year, the positive SST anomalies are over in the Eastern side of the Atlantic, heading towards the Barents and Kara seas.

This seems more in tune with the long term trend, of increasing amounts of heat being transported along the Gulf Stream from around the Carribean to around Siberia.

[Andrew Xnn]

Here are images of SST's from 2010 and 2011:

Overall, SST's are flatter this year compared to last year. However, there are a number of similarities between the 2 years as well.

Interesting that the Hudson Bay was so warm in Dec 2010 as it was brutally cold along the Great Lakes. Below average temps are evident off the US east coast in 2010.

Believe SST's have more to do with the jet stream than the Gulf Stream. Strong Greenland block in 2010, zonal this year.

[Chris Reynolds]

Happy New Year all!

Thanks for another interesting post Neven. My post on methane will be delayed, my internet/phone failed before Christmas and I'm only just back on, then I start work again next week. I'm also wrestling with a recent paper about bifurcations in Arctic sea-ice - Abbot/Silber/Pierrehumbert "Bifurcations leading to summer Arctic sea ice loss."

But people might find my most recent post of interest - about new research linking reduced Arctic sea-ice to a winter cold pattern in the Northern Hemisphere.
http://dosbat.blogspot.com/2011/12/cold-winters-arctic-connection.html

[Artful Dodger]

Thanks, Chris. For those that haven't seen the paper yet, a freely-available public copy is here:

http://geosci.uchicago.edu/~abbot/PAPERS/abbot-et-al-11b.pdf

The AGU page for the paper is here

Abbot et.al (2011) extends the work of Eisenman & Wettlaufer (2009), accessible here, previously discussed on the ASI blog.

Key Points from Abbot (2011):

• Bifurcations can occur as Arctic summer sea ice is lost in a low-order model
  
• Whether bifurcations occur is strongly dependent on cloud behavior

[Chris Reynolds]

Artful Dodger,

Thanks, I should have linked to the copy - it's where I got mine from.

Another key point is that during the transition to a seasonally sea ice free (what we're seeing now), tipping points are less likely than for the next transition , to a perennially sea-ice free state. That result is common to Eisenman & Wettlaufer who find tipping points more likely in the transition to a perennially ice free state.

At the risk of making my blog post superfluous: Another relevant paper is Abbot & Tziperman "Sea ice, high-latitude convection, and equable climates."
http://geosci.uchicago.edu/~abbot/PAPERS/abbot-tziperman-08a.pdf
It's a paper that I find scary.
"...the [perennially] ice-free state is stable for values that may be reasonable for the Arctic ocean during the late Cretaceous and early Paleogene (OHT = 0, CO2 = 250–2000 ppm,AHT = 80–100% modern)."
OHT = Ocean heat transport.
AHT = Atmospheric heat transport.

[IdiotTracker]

Interesting papers, guys. I framed them a little with stuff that is apt to be old news to the crowd here and made a post of it:

http://bit.ly/wgA1iR

[idunno]

Hi all,

A new study from NASA, top of the news feed top right, is interesting, and may be relevant...

Russian river water is freshening the Canadian Arctic, but leaving the Russian side as saline as before.