http://www.sciencedaily.com/releases/2011/01/110118123519.htm

Anyone got a handle on how many "We've overcooked the books" reports over the past 10yrs to balance out all the "worse shape than we thought...." papers?

I know as 'scientists' we are stuck with "in all probability'', "95% certainty..." etc. (you ask a scientist if the sun will rise tomorrow S/He will have to say 'probably'!!!) so we can expect an amount of erring on the side of safety but we seem to have had too many 'shocks' for us to languish in the 'it won't be that bad' zone.

The arctic is in far worse shape than most would accept, not only the amount of 'dark water' over summer  (and a faster melt out this year than last years 'record' plummet...more F.Y. ice than then esp. in 'prone' melt positions) but also (and you'll not see a lot of 'research' around this) the mashing of the Halocline layer (making 'deep ice' an impossibility)

This year will challenge/pass 07's melt due solely to the amount of F.Y. ice and it's propensity to 'melt out' in-situ (as we saw last year) . Even South Beaufort is now bereft of Paleocrystic ice!!! (not to mention the Canadian Archipelago!) so where will we see 'ice retention' this year?

Surely a min lower than 07' without a 'perfect storm' will be enough to convince even the staunchest Skeptik that we are in a novel and bad place???

Yes, if the change in the TSI is 3 Wm-2 then the average change on the earths surface is 0.75 Watts m-2.  (half of the earth is in shade) and the surface area of a sphere is 4*pi*r2 just a bit of geometry

Good idea - as long as you are prepared to accept that it was a good forecast if that proves to be the case, rather than - as I suspect - looking for another opportunity to mock.

Quite happy to stand (or fall) by what I say 4WD!! I believe that I have things 'correct' in my understanding so it will just prove a matter of 'watch and see'.

Even without the Cryosat2 data (where is our 'depth'/'volume' data???) it is easy enough to see where 'late' ice is forming and ,courtesy of the buoys, where the ice is exiting the basin from.

 We are all aware of the properties of F.Y. ice so really it's only the thickness data we lack. With a slow start to 're-freeze' and some notable di-pole behaviours (and associated ice flush out) I think we are looking at a pack whose 'central region' (hardest to melt out in situ?) is predominantly F.Y, ice with the surrounding pack already proven to be vulnerable to 'in-situ' melt out (East Siberian, Barents, Bering, Kara,Canadian Archipelago and now Beaufort) over the past 5 years.

I think it more the point why we feel the ice 'won't' melt out this summer?

Hi GW.

I am looking now at when we reach the maximum extent.  The date over the last decade has ranged from March 5th (in 2009) to March 31st (last year).  The average date is March 12th.

Assuming an average date this year, that means about 40 days to go.

The lowest maximum was in 2006 at 13,782k (followed closely by 2007).  Currently we are at about 12.7M.

The date and level of the maximum will give us some indication of how the Arctic will fare during the melt season - an early and low maximum will not be a good starting point.

But there is another and more dangerous ice than floe ice, as it takes many years for its formation. It is met with in isolated floes, but rarely if ever in pack below Smith's Sound, and the Scotch whalers seldom encounter it. Ships have been nipped hundreds of times in floe ice and escaped, but few if any have ever freed themselves from the fierce grasp of the ancient ice of the arctic, called by Nares floe-berg or Paleocrystic ice. This bears evidence of great age, the part above water being from fifteen to forty-five feet in thickness, which would make its depth from one hundred and thirty-five to four hundred and five feet ; the stout- est-built ship that ever put to sea would be crushed into match- sticks by the pressure of two such floes upon her sides. This ice forms the northern limit of the cruising-grounds of the American whalers north of Alaska. Some years it moves to the southward and closes up on them ; again, it recedes, disclosing more of the mystery of the farther north. Scattered here and there through it are yohjnias, or lakes of ice, of one year's growth, enclosed by heavy floes arched and keyed together.

Paleocrystic ice is old pack ice built up by successive deposits of snow during a long period of time, thus giving it an appear- ance of stratification. There is an alternation of soft white and hard blue ice, representing, respectively, compressed snow and water formed during the sunshine by thaws, and frozen at night or when cloudy. (It is a remarkable fact that snow will melt and seep through floe ice in sunlight though the thermometer may record far below the freezing-point.) Eventually, during the long summer day, the floe is left bare and dry, but soft and porous, unless so far north that the snow-storms continue all the year round. Over some strata are layers of atmospheric dust, such as Nordenskiold found on the Greenland glaciers ; also the gradual decrease of the thickness of the layers — due to pressure and in- crease of blue ice — because of greater infiltration, as the lower part of the berg is approached, make certain the progressive nature of the formation.

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Dug this out of;

http://en.wikisource.org/wiki/Page:Popular_Science_Monthly_Volume_35.djvu/701

to let folk read about the old 'Paleocrystic ice' that used to form the 'backbone' of the Arctic ice pack and formed most of the sea ice come ice min in Sept.

Sadly the last of this ice type disappeared in South Beaufort last July and ,with the mixing out of the halocline, the conditions that allowed it to be no longer exist in the Arctic Basin

You could equally have quoted the description of it breaking up if you had a different agenda.
If it could open and close on ships it seems to have been moving about a lot if it was supposed to be hundreds of feet deep?

"The breaking up and floating away of the ice-field, the debacle of the glaciers and disgorging of the fiords, impress man with his utter insignificance and weakness in the presence of such mighty forces. Fleets of lofty icebergs drift southward, urged on by deep under-currents, and plow their way through thinner ice, splitting, colliding, and overturning, always maintaining a cer- tain sphinx-like dignity — majestic and mysterious. Vast out- reaching tongues of ice extend from their hidden bases, as hard as rock and as dangerous to the unwary navigator, while to lee- ward drifts a convoy of smaller bergs, the debris of the first — a jostling following too rough for safe companionship."

And miles long don't forget! If you read the whole thing you'll find the areas that this ice type used to live in and the areas it could not 'navigate' due to it's draught. All moot seeing as it's all gone now though?

And .of course, the 'depth' of the ice would be difficult to measure but not the height (esp. when you have ships navigation equipment to hand) and once we have have the height......well!

http://www.cryocity.org/

Record melt in Greenland (2010).....seems we may need to re-visit how quickly the ice sheet melt will impact us all?

Mind you. Western Greenland is trendy at the moment.It has been quite warm this year.

It's just that the extension of the freezing season last year was just synoptics/weather also?.

Lets just call a spade a spade shall we?.

AIMSIR, I think you will find that there has been an alarming rate of melt in recent years, not just 2010.   I have read reports and seen photos of huge flows of meltwater disappearing into chasms in the ice.

I don't want to be alarmist but this is but another example of the destablisation that is occurring.  

Reports of massive meltwaters happen every year because that's what happens naturally,but are used imo, by some groups to further specific agendas through fear.

If we get back to 2007 levels with Arctic ice this year or in the next few years or if the Greenland ice cap shows serious signs of reduction in height I promise to throw my hat in and become a non sceptic.

I do take seriously the arguments for agw but find no solid science other than that provided by interest groups or politics for the theory.Neither is self correction to be found.imo

I see your point as being a non alarmist and from previous posts I accept that you are not in that catagory.btw.

Ps:The world is warming no doubt.My thoughts cannot concur with the theory of agw as the main driver for the moment.I am open to a change of opinion though ,as every sceptic should be.

I really don't think this is the case.  By all accounts, those who have studied the Greenland ice sheet for years report that the changes are recent and dramatic and increasing to escalate.

As for scepticism, that is absolutely fine.  I do think that nature has served up a particularly useful phase for us, with a quiet sun and strong la Nina and perhaps evidence of a long-cycle swing towards a cooler phase in the Pacific.  If we don't see a clear and sustained drop in global temperatures I can see the level of genuine scepticism dropping away over the next few years.  Even Stephen has conceded that this is the case.

Roll on 2011.

Btw.I appreciate your acceptance of sceptics,we are not all conspiracist looneys and paid by big oil companys.

Thanks.

Baffin has been rather chilly the last few days
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=INUNAVUT2&day=22&year=2011&month=1&graphspan=day
Interesting the station is using a Vantage Vue, seems to be coping for now.
I think this could be a temporary camp(?) has been reporting since late December.

The forecasts also pointed to very cold northerly winds, which would expand ice cover very rapidly. Something to watch.

http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=INUNAVUT2&day=22&year=2011&month=1&graphspan=day " href="http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=INUNAVUT2&day=22&year=2011&month=1&graphspan=day">http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=INUNAVUT2&day=22&year=2011&month=1&graphspan=day
Interesting the station is using a Vantage Vue, seems to be coping for now.
I think this could be a temporary camp(?) has been reporting since late December.

Originally Posted by: polarwind 

Yes, noticed the general trend there over the last few days and nearly posted about the chances of this likely to build sea ice cover in that area quickly.

The forecasts also pointed to very cold northerly winds, which would expand ice cover very rapidly. Something to watch.

Originally Posted by: four 

With the current alignment of the PV there is a very deep broad plunge of Arctic air deep into eastern Canada:

http://www.meteociel.fr/modeles/ecmwf/run/ECH0-0.GIF?23-12

Even down at the southern end of Lake Huron it's been down around -25 to -30C

But let's not get carried away here GTW. Once the 'basin' is frozen over the other areas are 'external' and would need anomalous cold to remain through the year (remember the 'ice factory' switching on across the mouth of Bering last year and how long that ice 'stayed for?).

The issue's (for me) are the timings of the Central basin melt as , the earlier it forms the thicker /less salty it is come 'thaw'. The other 'ice' type is the older ice which has 'matured' over a number of seasons shedding more and more of it's salty cargo as it ages.

As we know many 'sea areas' in the basin have only recently become ice filled and the very central region of the pole (maybe across into Bering?) has been 'flushed out' of the basin (to be replaced by 'new ice) via the Fram straight.

We know from last year that the Canadian Archipelago is a mixture of Arctic ice (floated into the Channels and Viscount Melville) and 'new ice' so this area will be interesting to watch this year as it may well prove a 'new' outlet for the Arctic ice to the North of it (via the channels and out through Baffin?) if it melts out before the end of July.In the past the channels were ice filled with some of the oldest ice in the Arctic effectively blocking the exits.

Another 'new' area to watch will be Beaufort as the last of it's Paleocrystic 'backbone' has now succumbed to the pressures of the melt season last year leaving only 'new ice' there.

In 8 weeks the 'build phase' will be over and the ice 'around the edges' may well be melting?

You should know me better than that.  I was observing nothing more or less than the fact that there is a deep and broad cold plunge of air down into the eastern side of Canada.  It does not has, nor was it intended to have, any greater significance or merit than that.

The Arctic ice extent continues substantially below what used to be regarded as the norm for this stage in the cycle.  We are a little ahead of 2006 still but that may not last beyond the end of the month.

The significance is that the very same area was notably slow to freeze up in the early winter.
Which was being portrayed as 'an issue'.
I think -40 will soon promote near normal sea ice there.

GTW , I wasn't having a pop at you, I think I have a 'handle' on where you are coming from but was a little surprised as to why conditions that might bring ice levels in Baffin/Hudson up to the recent 'average' were significant this late in the season? No offence meant.

I'd agree that as winter progresses and the A.A. declines (as the basin freezes over) and so 'normal services' can be resumed across the basin. In fact if they did not return to normal once the 'warm water' was sealed in it may well suggest that the A.A. wasn't occuring and all we were seeing were 'normal, natural' variations to circulation patterns in the Arctic and not a 'new' imposed pattern at each winters start?

On the 'weather boards' folk are looking for Snow like last years (both Jan/Feb and the past Dec) but I'd be very surprised if for the rest of winter we get more than the odd toppler over us?

As for an extended period of -40c 'beefing things up' to normal levels? I don't think so. The ice and snow cover insulate the waters below and with the lack of the 'deep Halocline' all any thickening brings (due to snow cover on top) is basal melt of the ice at the base of the pack leaving even weaker 'cover' above (and the 'wobbly ice' expeditions found last year when walking on '3m pack' ),anyone throwing a snowball into water knows how quickly it melts compared to solid ice?.

Any 'resumption' of normal Arctic processes merely guarantees a warmer lower latitude come spring and so a faster melt of the peripheral ice.

Once the high Arctic is again bathed in sun for over 12hrs a day any of the folk doubting the fragility of the 'New Arctic' need to watch what happens up there (esp. over 80n).

Hi Dave, yes it might.  But as I have commented previously, we are not seeing unique or unusual synoptics at the moment - indeed since the New Year we are seeing very typical synoptics with a tight PV and a lot of the cold air held in Arctic regions.  Yet still the ice isn't recovering and the daily increase is following a fairly typical build but from a historically lower base that previously.

If, as I think is the case, ice is being lost through a mixture of

(a) transport out of the basin, because we have lost the stability afforded by the old mulit-year ice

(b) melt from below due to warming ceas

(c) warming from above if any warm air masses are advected north (not currently an issue, unlike pre-Xmas)

If (a) is a real issue then we are looking at a long-term problem, because - by definition - restoring multi-year ice has to be a multi-year task and only thicker multi-year ice is going to withstand the break-up caused by ocean swell and the other factors (summer melt being a major one).

I am expecting this summer to provide a few more pointers.  A lot was made of last year's late peak and apparent continued bounce-back from 2007, yet look where we ended.  If we start, as is possible, from a lower and earlier maximum and have a further sequence of unhelpful synoptics then new lows are probable - given the points above.