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Kevin McKinney

Hmm, the words "Pacific warmth" come to mind, somehow.

Andrew Xnn

Not much warmth in the Pacific; but it's Hot in Russia:

Kevin McKinney

Well, not on the surface near the Bering Strait, no. (Lots in the Bay of Biscay, and off the Labrador coast, though--even if the latter isn't showing in the 2m air temps.)


I wonder about deeper layers, though.

Artful Dodger

2M air temps are not predictive of melt. You need to track SSTs. Air rapidly takes on the sea (or ice) temp, but contains 870X less heat per volume. Melt caused by air is minimal compared to the melt caused by warm water and solar insolation. These are the real sources of heat driving the Arctic melt season.

Daniel Bailey

Interesting bit just published on energy transmittance through melt ponds:
"Acceleration of sea-ice melting due to transmission of solar radiation through ponded ice area in the Arctic Ocean: results of in situ observations from icebreakers in 2006 and 2007" Itoh et al 2011 (open-access copy here).

Gonna be a hot one.


Artful Dodger, I can see how air temperature does not itself impart heat to the surface of the ice, but it seems like air temperature and movement would either serve as a trapping or a wicking mechanism for reradiated insolation.

I'm thinking of fur on animals or trichomes on a leaf as illustrating what I mean. Both fur and trichomes serve to disrupt the otherwise smooth flow of surrounding air, trapping heat (or cool air) in the case of fur or water vapor in the case of trichomes. (Even leg hair on humans does this. When I shave my legs, it's chilly!)

Ice isn't very rough, so it seems like most reradiated heat would dissipate quickly if there's any kind of a breeze; however, I could see pockets forming in the ice where reradiated heat could pool and produce a feedback mechanism. These localized sheltered areas could keep latent heat from being lost via evaporation or sublimation, thereby contributing to melting of the ice in that location.

(The flip side of this, of course, would be the swamp cooler effect, where warmer water molecules in water or ice are whisked away, cooling the surrounding water or ice and discouraging the formation of melt ponds.)

Or am I conceptualizing this all wrong?

Artful Dodger

The United States Coast Guard Cutter HEALY has departed for Arctic West Summer 2011.

Rlkittiwake: Sea ice receives heat energy from incoming shortwave radiation (direct insolation). The reflected part OLR may be absorbed by GHG's. As their concentration grows, equilibrium temperature rises. It's about the energy budget.

Artful Dodger

Shave Ice? Da kine, Healy!

Artful Dodger

headed to Honolulu ...


Hi all,

(Drunk, this will be my third attempt to post here. Pls forgive abbrv)

Looking at latest maps, seems passages opening early, after closing late.

Possibly more significant, IMO, than overall Arctic ice area/extent.

Anybody got any data on the dates of the Passages opening in previous yesrs?


Hi all,

Me again, and the caffeine is kicking in...

Since the year 2000, the Northern Passage has been open and clearly navigable, in the absence of any surface ice along any of its route between the following dates:

2002 15 Aug 2002 til 2 Sep 2002 - 17 days
2008 1 Sep 2008 til 5 Oct 2008 - 35 days
2009 1 Sep 2009 til 11 Oct 2009 - 41 days
2010 27 Aug 2010 til 10 Oct 2010 - 44 days

It is more difficult to eye-ball the NorthWest Passage, and I have used the central, most direct route through the Canadian Archipelago to draw up these dates of opening:

2007 10 Aug 2007 til 19 Sep 2007 - 39 days
2010 16 Aug 2010 til 30 Sep 2010 - 44 days

Immediately noteworthy is that 2010 is the first year when both Passages were open simultaneously, and for the longest period of time. It may even be legitimate to present this information in the following way:

Number of total ice-free days along the surface of the Passages, combined:

2000 0
2001 0
2002 17
2003 0
2004 0
2005 0
2006 0
2007 39
2008 35
2009 41
2010 88


Hi all,

I have just been rechecking the figures given above, using archived images presented at the excellent Neven's sea ice blog.

Just to say that the figures given above are highly subjective, er, um, by which I mean, just plain wrong.

Having said this, they apparently understate the extent to which the Passages are opening for longer. So the point remains, but the data above is pretty worthless.

For instance; I have, based on eye-balling archived CT images, 5which are somewhat unclear and incomplete) stated that the Northern Passage opened on 27 Aug 2010. An archived post, with a clearer map, here shows it as clearly fully open by 10 Aug 2010.

My bad. If anybody else can provide any better data, I would be delighted to hear it.

Rob Dekker

Idunno, thanks for the attempt.
Seems that the caffeine is not helping ? :o{

Either way, it would be interesting to get your table (of simultaniously open east and west passage) corrected, since it is an interesting metric of changes in the Arctic.


Hi Rob,

Agreed, but I personally am unable to find any archive of images to allow me to make any reliable attempt. So I have to pass.

On a related theme, I'd also like to raise the possibility that this year we may be about to witness the opening of a third passage. This one would start in the Fram Strait, pass straight through the Pole and on, via East Siberia, to the Bering Strait.

The patterns now visible on both UniBremen and CT ice concentration maps would seem to suggest that this is possible. There is also the apparent lead developing and visible on the North Pole webcam, which was last highlighted here on SIE 6 - unperturbed.

When TOPAZ3 was last posting information it seemed to me that ice in the quadrant between Cap Maris Jessup, Svarlsbard and the Pole was very thin indeed. If this has thinned enough, it could radically change the forces acting upon warm Atlantic water flowing Northward towards the Arctic.

I do not have the vocabulary to describe what I mean very well, but it is (or could be)similar to a dam, an embankment or levee breaking; but much less dramatic, as the forces involved are just differences in buoyancy gradients, not full-on gravity...

At any rate, warmer water will ordinarily hug the surface, as will fresher water. That's a trade off. A thick barrier of floating ice will fend off warmer water currents, and divert them from the region of the Fram Strait towards the East Of Svarlsbard. But if the ice in the Fram Strait becomes thin enough, or fragmented enough, that could become the path of least resistance.

I'd like to suggest that this might be what is visible currently on the latest sea ice concentration maps. As often, I'd welcome disagreement, refinement, or any comment from any of the many with more sense than me. Or less, I'm not fussy.

michael sweet

Warmer water does not hug the surface. Colder water is less dense than warmer water near the freezing point. You also have to consider salinity and the Atlantic water is often saltier. The relationship between salinity, temperature and density is complex. Much of the Arctic Ocean is warmer at depth than the surface. Unfortunately I do not have a good reference for density relationships in the Arctic.


Hi Michael,

(Enjoyed your artcile on Skeptical Science and commend it to anybody here who hasn't found it yet.)

But I think you're wrong about colder (sea) water being less dense than warmer (sea) water near the freezing point. This only applies to fresh water.

Certainly, though, the whole relationship between salinity temp and density is very complex.

Since starting this hare running here, I've noticed how far off the original topic it is... I might continue on the last opne thread...

Janne Tuukkanen

Doesn't Gulf Stream pump act like this: Warm salty water travels to the north, due evaporation its relative salinity rises, due which it apparently sinks down, under less salty, cold northern waters?

Hmm... But ice formation also increases the salinity of leftover water. Complex indeed :)

michael sweet

Janne's description is correct. The relationship is complex and depends on the salinity and the temperature. For one example, the water at depth under the Peterman Glacier tongue is warmer than the melting point of the ice but it is denser than the higher water. Much of the Antarctic has warmer water at depth than at the surface. Much of the Arctic also has warmer water at depth, the Atlantic water does not enter the Arctic at the surface.

Christoffer Ladstein

Based upon the IJIS Sea Ice Monitor,it seems the Northern Passage will open at an incredibly early date this year, I predict 3 weeks prior to last years date.

Rather ironic (or a coincidence?!)22. august was the first date for ice-free Northern Passage last year, because this was almost the same date "The Northern Passage", the trimaran we all remember so well to sail both passages in 1 season, were battling their way through to the laptev sea, and thereafter hardly getting in touch with ice until some nautical miles east of the Cambridge bay.

Here is the blog for those that didn't have the chance to follow last years race!


Day 5 in the Arctic by canoe (saturday), 83 degrees north heading for the pole - little open water still according to ut.no.

Funny, they was visited by a housefly at 83 degress north:

- Rune had another highlights when he received a visit today. A housefly flew by and sat down on his sledge before it flew off again.

Kevin McKinney

Realclimate has a post about the Aquarius mission which launched recently, and which will be observing ocean salinity. Good discussion about salinity, temperature and density--also about a NASA salinity quiz which people are having fun with.

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