Arctic Ice Discussion (The Melt)

[karyo]

You can't have been following it for even 2 years then, 2010 was quite a bit closer

Yes, it happened later in the season but it was closer.

Karyo

[Methuselah]

I agree with you, but by using the language you do, you have inadvertedly become part of the politicisation and therefore part of the problem.

Tbh, I think that most of us have that problem? Anyhoo, I do have difficulty in finding the words that would enable me to distinguish between hard-working sceptics (without whom science would never advance at the rate it does) and those who I'll now refer to as 'others' - folks whose minds are a priori set on the opposite of qualified, or unqualified, acceptance...It's hard to be perfectly neutral in a world where the avialable language-structures are anything but...

[loafer]

True. It's hard work being objective!

[Gray-Wolf]

http://www7320.nrlssc.navy.mil/hycomARC/arctic.html

If we look at both the 'thickness and 'drift' plots , and then compare with;

http://arctic.atmos.uiuc.edu/cryosphere/

we can see the very real possibility of the late 'gains being nothing more than 'spread' from the central mass toward the south. If we look at both Fram and the Baffin Bay area we can see that drift pressures to the south have been strong (most of the time) from these areas to the south (the 'thickness plot just looks depressing with all of the thicker ice within the 'Trans Polar Drift' and drifting at a rate of knots toward Fram!)

By the end of April we will see a more 'representative plot for both Ice and snow cover across the basin and so I , for one, am again holding my tongue until then lest I make a fool (good day for it!) of myself by describing things which are no more than a will'o'th'whisp' phenomena?

[4wd]

If it spreads presumably this leaves thinner areas if not patches of open water further north which still can freeze deeper = more ice volume.

You are describing normal behaviour not something new and somehow out to confuse the unwary.

Edited April 1, 2012 by 4wd

[BornFromTheVoid]

http://www7320.nrlss...ARC/arctic.html

If we look at both the 'thickness and 'drift' plots , and then compare with;

http://arctic.atmos....edu/cryosphere/

we can see the very real possibility of the late 'gains being nothing more than 'spread' from the central mass toward the south. If we look at both Fram and the Baffin Bay area we can see that drift pressures to the south have been strong (most of the time) from these areas to the south (the 'thickness plot just looks depressing with all of the thicker ice within the 'Trans Polar Drift' and drifting at a rate of knots toward Fram!)

By the end of April we will see a more 'representative plot for both Ice and snow cover across the basin and so I , for one, am again holding my tongue until then lest I make a fool (good day for it!) of myself by describing things which are no more than a will'o'th'whisp' phenomena?

Some of the ice gains have been from ice along the Kara coast being blown west past Novaya Zemlya. The ice lost there is being replaced with new thinner ice though, but that's a normal process. The dipole anomaly pattern hasn't been present most of this winter so while there will always be a little ice loss through Fram, I don't think it's anything unusual at this stage. More of the ice gain has been in the sea of Okhotsk and we can definitely say that has nothing to do with ice in the central pack spreading out. One thing that does seem a little unusual is the flow of ice from the Beaufort and Chuckchi seas out through the Bering strait over the last week or so.

Something that may be of concern about the pattern this year, is that we may find the ice along the Eurasian coastline melting out very early, allowing for the ssts to warm up a lot during the summer. Then come cooling time in late August and September, the release of the heat here may promote a strong +ve dipole pattern

With the guesses for the minimum this year, what source will be used?

[VillagePlank]

Just being naughty ....

Cherry-picking at it's best!!!

[oldsnowywizard]

see we are back on to the ice spread argument again... surely there isn't any 10 meter plus ice left to warrant a spread from the mid basin? and surely ice doesn't simply spread out until its 1cm thick on the surface? and surely this isnt a new mechanism over the last 5 years and actually happens every spring? in fact why hasnt it happened more so during past melt seasons due to there being more ice to spread? maybe its ocean currents and about 50 other variables all behaving as normal...please note I said maybe...

[BornFromTheVoid]

see we are back on to the ice spread argument again... surely there isn't any 10 meter plus ice left to warrant a spread from the mid basin? and surely ice doesn't simply spread out until its 1cm thick on the surface? and surely this isnt a new mechanism over the last 5 years and actually happens every spring? in fact why hasnt it happened more so during past melt seasons due to there being more ice to spread? maybe its ocean currents and about 50 other variables all behaving as normal...please note I said maybe...

I presume GW meant the spread of high concentration sea ice southward where even though it's the same amount of ice at the start (sometimes less) because it still stays above whatever coverage threshold, it counts as growth.

Nothing new of course, just occurring more so nowadays because the ice is less consolidated and more open to wind blown movement.

[4wd]

...... occurring more so nowadays because the ice is less consolidated and more open to wind blown movement.

In what way exactly.

This sounds like a major presumption that won't stand much analysis.

[BornFromTheVoid]

In what way exactly.

This sounds like a major presumption that won't stand much analysis.

Which are you questioning? The less consolidated ice nowadays or the fact that the wind affects broken up ice more? Both?

Saying it won't stand up to analysis is also being presumptuous by the way!

[4wd]

Would there not always be as much if not more of this somehow inferior ice all round the edges in a more extensive frozen area?

[karyo]

The ice extent is continuing to look good from where I am standing!

http://nsidc.org/dat..._timeseries.png

Karyo

Edited April 5, 2012 by karyo

[pottyprof]

The ice extent is continuing to look good from where I am standing!

Will we make it over the average line? Certainly looks a possibility. It would be good to see that's for sure.

[Geordiesnow]

Even if it did, what will it mean exactly? Too me, the fact that the winter extent has generally remained fairly close to the lowest extent on record and the fact that it would appear parts of the Kara sea could be losing its ice soon because its so thin as it never really frozed over during the winter months means that even if it does touch or go above that line, for me it will be nothing more than just for show really. It would be more encouraging if the winter extent was higher than in previous years but in general it has been fairly low mainly thanks to the low sea extent on the Atlantic side of the Arctic.

Also looks like too me the upper air temps/ground temps are fairly high for the time of year, especially in the Kara Sea and despite a more NAO, it looks like the set ups still look fairly favourable for ice to exit through the fram stright, although someone more knowledgable than me can confirm if thats the case or not.

My prediction for the melt season is as follows: Low sea extent, perhaps record breaking low extent at the end of the Spring season due to the thin ice in the Kara Sea which normally should not melt until around June time but I think if the warmish temps continue it could be gone by the end of this month, and plus the other natrual melt which occurs at around this time of year. Alot will depend what the summer weather patterns will bring which may decide the summer extent but if we see a cool summer then perhaps somewhere near 2009 could be a good aim, if not then something similar to last year looks likely.

Should be interesting nonetheless and how will the above average extent during the whole of the winter in the Bering Sea will affect the ice there, last year was very mild during March where as this year its been below average, it may help too keep the ice on the Pacific side of the Arctic for a bit longer than last year which may protect the basin more, hopefully.

[BornFromTheVoid]

Would there not always be as much if not more of this somehow inferior ice all round the edges in a more extensive frozen area?

There has always been plenty of it, yes. But seen as the majority of the sea ice is thinner nowadays, it breaks up sooner and much more easily. Once it's in that state, all the extra ice edges from the free flowing pieces would allow the wind to generate more friction and drag than if flowing over a relatively smooth continuously icy surface. At least that's what makes sense in my head

[4wd]

I think it's unlikely there could ever be that much difference in the amount of this imaginary wrong sort of ice.

It's most likely yet another one of many little buzz phrases that get repeated round the blogosphere until they are perceived as fact.

[BornFromTheVoid]

Buzz phrases? What are you talking about 4wd? There are many different types of sea ice, but I'm not referring them. Just that the ice is now thinner and so breaks up easier, is that so hard to grasp?

[BornFromTheVoid]

Anywho... looking ahead for the next week or so, conditions in the near term look relatively good. The coldest air remaining around the Arctic sea ice peripheries, which should help to keep the extent looking relatively good. Some minor losses around Hudson Bay and perhaps the Bering sea. There is a moderate air flow going from the central Arctic through Svalbard and into the Greenland sea. While this may flush some ice out from the central Arctic, at this time of year it's still cold enough for the ice to be replaced with fresh sea ice, so it shouldn't impact the extent quite yet.

Out to t96 and things start to look a little different. the low across the Barents has intensified, which may begin to impact the sea ice extent here and in the Kara sea, possibly spreading out and reducing some of the coverage below the 15% extent coverage threshold. At the same time, a storm system is in place across the Bering sea which may cause the first significant losses of the melt season there. All the while, temperatures remain mild across Hudson bay, perhaps resulting in a very early beginning to the melt there.

Out to t168 and conditions are quite similar across the Atlantic side, but with cold air still in place across the Barents and Kara sea's, extent losses shouldn't be too bad. The storm over the Bering sea has moved on but milder air has taken its place. Colder temperatures have returned to Hudson Bay though, which should slow or stop the losses there.

Overall I'd say it's 50/50 with whether we hit the average extent line on the NSIDC graph or not in the next 4 days. After that, I think the chance may be gone for this year. The ice in the Kara and Barents sea is already in very poor condition, as can be seen in the modis image, so that area is something of a wild card for the next few weeks and may react much more poorly to the upcoming conditions than I've anticipated.

[Gray-Wolf]

I'd agree with BFTV that the ice is generally in poorer condition these days and that is across the basin not just the edges. As you know I use;

http://www.woksat.info/wos.html

to watch the ice over winter/Spring and , over the past 5 years, the extent of leads (their appearance ,size, number) gives the definite impression of a more disrupted pack overall.

As for drift off from the pack edges (spread from 100% concentration to less) this has tended to 'bully up' some posters as they mistake this as growth. I had given up pointing out the error of their ways but will re-visit it again here. The Bering ,Baffin and Fram sea areas all suffer from this and it can lead to some fast oscillations in extent figures (both 15 and 30% 'cutoffs) but , being peripheral, we can see the state of the ice via a quick peep at the Modis visual images. It would seem that this does not suit some folks agenda's and they would prefer to stick with the data that suites them best??

Folk new to the Environment boards might do well to note these folk here as you will find that they tend to be similar with other subject areas?

[songster]

As for drift off from the pack edges (spread from 100% concentration to less) this has tended to 'bully up' some posters as they mistake this as growth.

This can't be a very significant effect as area and extent are staying pretty much in lock step. At this time of year there are no melt ponds to confuse the issue, so it's safe to compare area and extent directly. The growth is real, if thin.

[oldsnowywizard]

Now we will start to see the extent dropping .. Conditions are warming up quickly and the thinner Ice around Kara will go quite quickly ... It will be interesting to see what happens on the Canadian side this summer as for much of the winter it had -30 to -40... We will see if temperature indeed has much impact locally or if other variables will over ride . I think we should see another step up this summer for ice rentention with lots of roller coaster riding along the way ..

[BornFromTheVoid]

A quick overview of the winter season, November 1st to March 31st

925hPa Temperature Anomaly

Mean SLP

SLP Anomaly

Wind Vector Anomaly

Sea ice age and distribution as of March

One of the main questions for the melt season is whether we see a continuation of the enhanced and extended Icelandic low with southerly winds across the Atlantic side of the Arctic, or if we see a switch back to a more +ve dipole anomaly pattern with strong ice export, as has been the case since 2005. A continuation of the winter pattern will be best for maintaining what little thick ice is left and slowing down the melt, but if even a weakly +ve dipole anomaly pattern returns, we may well challenge the 2007 extent.

As has been mentioned, a rapid melt along the Eurasian coastline looks likely, especially in the Kara, Barents and Laptev sea's. If the SSTs here warm up much, it may promote a tendency for lower pressure, perhaps encouraging a more +ve dipole pattern. Anyway, lots to watch for the next few months.

[BornFromTheVoid]

The NSIDC has updated their daily sea ice extent (free to download and no registration required) to the end of 2010

http://nsidc.org/data/nsidc-0192.html

[Gray-Wolf]

http://polarbear.colorado.edu/IceAge.html

The above is a very useful tool allowing even the deniererist of deniers to see how the ice has changed over the past 28years. You can run an animation of the 'ice age' composition of the pack for any chosen month over the 28 year period. Though not snooker I'd advise folk to 'Keep your eyes on the red'.

That ties in nicely with BFTV's post showing current ice 'age' breakdown.....at last a break from those droning vioces telling us older ice is recovering, it is not.

We may see fluctuations as we approach a seasonal pack (and even after as 'seasonal' will surely not become the instant 'norm' for the Arctic?) but I feel convinced, by both the experts opinions and what i have witnessed through my life, that we are on a one way trip to a seasonal pack