Polar Ice Extent

[Thundery wintry showers]

It makes sense to me- if the Arctic is set to warm at, say, twice the average rate of the Northern Hemisphere, then it means that there will be less of a contrast in temperature between polar airmasses and the oceans at relatively low latitudes. They also talked about the amount of polar lows approximately halving, rather than becoming a thing of the past altogether.

But if global temperatures rise by enough to initiate the effect they're describing then a large majority of our northerlies won't be cold enough for snow anyway, barring high ground in the north and so it will be largely moot whether we get polar lows or not.

[Guest mycroft]

In my opinion it doesn't make any real difference to russia and the rest if the ice recovers or not. Russia already have nuclear powered ice breakers which can slice through ice thought to be impenatrable only 5 years ago. They are in the process of building a floating nuclear reactor than can be put in place in the artic and can power a small city and deal with the harshest of winters. So please don't use the fact that nations are arguing about who owns minerals resources in the artic as a an example as to why the artic may not recover. Fact is technologhy has moved way beyond caring about the weather and whether there is more ice or not

Very curious as to how any nation is going to be willing to gamble billions of dollars on putting a oil rig/platform in the Arctic ocean and to try and drill.No matter how much technology has moved on the risk is too big,financially,and enviroment wise, no matter how many nuclear reactors they put up there, a trillion of tons of ice moving won't be stopped why risk all that when they have large oil/gas reserve's on land already :lol:

It makes sense to me- if the Arctic is set to warm at, say, twice the average rate of the Northern Hemisphere, then it means that there will be less of a contrast in temperature between polar airmasses and the oceans at relatively low latitudes. They also talked about the amount of polar lows approximately halving, rather than becoming a thing of the past altogether.

But if global temperatures rise by enough to initiate the effect they're describing then a large majority of our northerlies won't be cold enough for snow anyway, barring high ground in the north and so it will be largely moot whether we get polar lows or not.

TWS are seriously saying that the Arctic winter will warm to mild wet climate despite there being no sun for months on end??? :help:

Edited September 23, 2010 by mycroft

[stewfox]

Stewfox, I'd imagine each summer the main areas of melt vary meaning different sections holding different ice ages melts. I think we'd need another few years to determine if anything is improving wrt ice age, because even before 07, there was plenty of variance. Also with extents not dropping below 07, something had to be increasing since then.

It was more to do with the tone of the report.

I dont think anyone would suggest the artic is in recovery or there has been any improvement since 2007

I just wish they had included the 2009 figs and made comment on 2/3 yr ice rather then the 5yr.

Overall extents are never far off the long term mean (maybe 1m short but nothing like the mins).

I hope for a max of 15m by next March

Very curious as to how any nation is going to be willing to gamble billions of dollars on putting a oil rig/platform in the Arctic ocean and to try and drill.No matter how much technology has moved on the risk is too big,financially,and enviroment wise, no matter how many nuclear reactors they put up there, a trillion of tons of ice moving won't be stopped why risk all that when they have large oil/gas reserve's on land already :lol:

TWS are seriously saying that the Arctic winter will warm to mild wet climate despite there being no sun for months on end??? :help:

I would assume they have a few people that would carry out a risk assessment and guess it wouldn't be a billions dollar 'gamble'

[Thundery wintry showers]

TWS are seriously saying that the Arctic winter will warm to mild wet climate despite there being no sun for months on end??? :lol:

Nope- only speculating on a plausible scenario where the Arctic warms at twice the rate of the Northern Hemisphere average.

E.g. if the Northern Hemisphere warms by 3C, then under that scenario the Arctic warms at 6C, and therefore the contrast between Arctic airmasses and the oceans further south ends up smaller. But the Arctic would have to warm by well in excess of 10C for its winters to become mild and wet.

If you're wondering about the comment about "most northerlies wouldn't be cold enough for snow", it's because, for example, most northerlies that produce snow are accompanied by temperatures near freezing, so a rise of 3C would result in rain. This isn't a hard and fast rule for northerlies though, e.g. the northerlies of early January 2010 widely delivered snowfalls with temperatures around -3C, so we'd probably need a warming at the high end of the IPCC's range to cut out snowfalls from similar synoptics to those.

[Methuselah]

It makes sense to me- if the Arctic is set to warm at, say, twice the average rate of the Northern Hemisphere, then it means that there will be less of a contrast in temperature between polar airmasses and the oceans at relatively low latitudes. They also talked about the amount of polar lows approximately halving, rather than becoming a thing of the past altogether.

But if global temperatures rise by enough to initiate the effect they're describing then a large majority of our northerlies won't be cold enough for snow anyway, barring high ground in the north and so it will be largely moot whether we get polar lows or not.

To me too, it makes perfect sense, Ian...There have been times in the past when the Arctic was almost (if not entirely) ice-free. The fossilized leaf-matter found there (dating from within the last 65Ma, I believe?) proves that.

What's more AGW had nothing to do with it!

[stewfox]

If you're wondering about the comment about "most northerlies wouldn't be cold enough for snow", it's because, for example, most northerlies that produce snow are accompanied by temperatures near freezing, so a rise of 3C would result in rain. This isn't a hard and fast rule for northerlies though, e.g. the northerlies of early January 2010 widely delivered snowfalls with temperatures around -3C, so we'd probably need a warming at the high end of the IPCC's range to cut out snowfalls from similar synoptics to those.

We should start to see a reduction in max extent over the years then.

I thought the attached graphs were interesting (re how max extent compares over the last 30yrs)

http://www.skepticalscience.com/On-the-Question-of-Diminishing-Arctic-Ice-Extent.html

[BornFromTheVoid]

Hows about a little competition?

As we are now in the ice growth season, why don't we take a few guesses, such as the dates we will reach certain benchmark extents, like

6,000,000km2, 8,000,000km2, 10,000,000km2, 12,000,000km2 and the overall maximum extent and date?

Here are the averages, roughly anyway, going by J1's excel work (feel free to correct me on these!). It will be 79-07 average followed by 03-09 in brackets.

6,000,000- N/A (Oct 5th)

8,000,000- Oct 11th (Oct 24th)

10,000,000- Nov 10th ( Nov 23rd)

12,000,000- Dec 10th (Dec 22nd)

Max- ~14.750,000 Mar 8th (14,195,580 Mar 8th)

Here are my guesses

6,000,000- October 11th

8,000,000- October 28th

10,000,000- November 24th

12,000,000- December 20th

Maximum Extent- 14,592,000km2 March 17th

[stewfox]

Hows about a little competition?

Here are my guesses

6,000,000- October 11th

8,000,000- October 28th

10,000,000- November 24th

12,000,000- December 20th

Maximum Extent- 14,592,000km2 March 17th

Good idea

My punt

6,000,000 - October 6th (rapid re freeze similar to 07 and 08)

8,000,000 - October 23rd (reasons as above)

10,000,000 - November 22nd

12,000,000 - December 17th

Maximum extent 14,456,450kms March 12th

Edited September 24, 2010 by stewfox

[Thundery wintry showers]

We should start to see a reduction in max extent over the years then.

I thought the attached graphs were interesting (re how max extent compares over the last 30yrs)

http://www.skepticalscience.com/On-the-Question-of-Diminishing-Arctic-Ice-Extent.html

It will take a lot of global warming to significantly reduce the winter maximum ice extent, because in practice higher temperatures are often matched with increasing precipitation, and if we're talking the difference between, say, averages of -10C and -5C, most of it still falls as snow. I think that's why we see an increasing discrepancy between the maximum and minimum.

The points about SSTs are interesting and also make sense, ice is more likely to melt more quickly, and form less quickly, if surrounding SSTs are higher, with a nonlinear relationship.

[NorthNorfolkWeather]

Good idea

My punt

6,000,000 - October 6th (rapid re freeze similar to 07 and 08)

8,000,000 - October 23rd (reasons as above)

10,000,000 - November 22nd

12,000,000 - December 17th

Maximum extent 14,456,450kms March 12th

My Guess

6.000.000 October 8th

8.000.000 October 23rd

10.000,000 November 23rd

12,000.000 December 16th

Max extent 14,765.000 March 19th

[BornFromTheVoid]

IJIS has updated with a big increase in yesterdays gain to 58,750km2.

The upper cold pool is developing very nicely now and by the 30th, the GFS has it looking one of the healthiest and most widespread of the last decade with nearly all the the Arctic ocean below -5C, 3 quarters below -10C and nearly a third below -15C at the 850hPa level. Will this be enough to counter the warm SSTs though, and allow the cold to build at the surface?

[Gray-Wolf]

My bathroom (with a full ,hot, bath) stays pretty steamy for a while with the light off???

And it's not 2 miles deep either???

[BornFromTheVoid]

Small enough increase today of 20,000km2. Perhaps another large upwards adjustment later? The synoptic forcast still favours increased sea ice extent and new growth, with favourable wind conditions and a growing and deepening upper cold pool. Will be interesting to see how quickly the cold and ice can deal with those anonamously warm ssts near the Bering strait...

C'mon GW, have a punt at the ice extent dates over the coming months! Twould be interesting to have guesses from as many viewpoints as possible.

[Gray-Wolf]

I will NDS, I just need a bit of 'time' to settle to it! (got a house full at the mo.!)

But before I do that I'd guess that, as for the past 4 years, formation will be slow and halting possibly leaving Dec with another 'low' extent figure (before 'winter kicks in' across the lower latitudes and we get the peripheral waters freezing off China/Bering/Hudson and the Great Lakes/Baltic etc).

If we get another 'similar' winter (A.A. and low solar 'lag') to last years then poor formation/thickness in the basin will be supplemented/augmented by ice the ice forming in the temperate zones.

[stewfox]

I will NDS, I just need a bit of 'time' to settle to it! (got a house full at the mo.!)

But before I do that I'd guess that, as for the past 4 years, formation will be slow and halting possibly leaving Dec with another 'low' extent figure (before 'winter kicks in' across the lower latitudes and we get the peripheral waters freezing off China/Bering/Hudson and the Great Lakes/Baltic etc).

If we get another 'similar' winter (A.A. and low solar 'lag') to last years then poor formation/thickness in the basin will be supplemented/augmented by ice the ice forming in the temperate zones.

Surely the early re-freeze (above average) is the easy bit. Much of the melt last 4 weeks will re freeze next 2 weeks.

On a side note could the big changes in IJIS (2nd readings) be mis reading open water which is in fact ice ?

I know roughly how IJIS works but real detail even on their own site is lacking.

Edited September 25, 2010 by stewfox

[WindWatcher]

Small enough increase today of 20,000km2. Perhaps another large upwards adjustment later? The synoptic forcast still favours increased sea ice extent and new growth, with favourable wind conditions and a growing and deepening upper cold pool. Will be interesting to see how quickly the cold and ice can deal with those anonamously warm ssts near the Bering strait...

Now updated to a more respectable 58,594km2 increase, taking us over 5,100,000km2

[Gray-Wolf]

Maybe we should be focusing on ice and not merely extent? As with the summer melt some folk spend too much time fascinated with 'extent' and not the quality of the ice in the basin. Hopefully , at some point, we'll get the cryostat data and be able to monitor thickness (and not 'age' or 'extent') to get a better feel for the 'health' of the ice in the basin?

[stewfox]

Maybe we should be focusing on ice and not merely extent? As with the summer melt some folk spend too much time fascinated with 'extent' and not the quality of the ice in the basin. Hopefully , at some point, we'll get the cryostat data and be able to monitor thickness (and not 'age' or 'extent') to get a better feel for the 'health' of the ice in the basin?

So focus on extent when its going down but not when its going up

I'm sure thickness will extend in the next couple of months as well

[BornFromTheVoid]

Now updated to a more respectable 58,594km2 increase, taking us over 5,100,000km2

That's much better! Between the 15th and 30th (so far) we've had 3 days with gains over 50,000km2, that's better than than 03,06 and 09. With favourable conditions for the foreseeable future, there's no reason why these type of gains shouldn't continue.

[NorthNorfolkWeather]

Will be interesting to see how quickly the cold and ice can deal with those anonamously warm ssts near the Bering strait...

My take on those temperatures. both the Chukchi and the East Siberian Seas are very shallow, so with an upper cold pool will lose heat rapidly. The Bering on the other hand goes from very shallow to very deep. I would think there's more heat in the deep part than all of the Chukchi sea. But a lot of that is already frozen....

Edited September 25, 2010 by NorthNorfolkWeather

[ghrud]

My bathroom (with a full ,hot, bath) stays pretty steamy for a while with the light off???

And it's not 2 miles deep either???

Everyone to their own... it's entirely up to you what you get up to in your bathroom.

[BornFromTheVoid]

My take on those temperatures. both the Chukchi and the East Siberian Seas are very shallow, so with an upper cold pool will lose heat rapidly. The Bering on the other hand goes from very shallow to very deep. I would think there's more heat in the deep part than all of the Chukchi sea. But a lot of that is already frozen....

Could be right, though even in the Arctic, it will take a while to reduce +6C sst anomalies. I don't think we'll have to worry about ice in the Bering sea for another 6 weeks at least anywho.

Which is already frozen? As far as I can tell both Chukchi and East Siberian seas are practically ice free?

[oldsnowywizard]

Maybe we should be focusing on ice and not merely extent? As with the summer melt some folk spend too much time fascinated with 'extent' and not the quality of the ice in the basin. Hopefully , at some point, we'll get the cryostat data and be able to monitor thickness (and not 'age' or 'extent') to get a better feel for the 'health' of the ice in the basin?

we have to use what we have to use... extent has more years of data ergo we are comparing apples with apples. we need at least 5 years of cryostat to be able to start comparing thickness values etc.. interesting to see what looks to be the earliest sharp increase in extent according to ijis.. not far off of 2005 extent figures now! and I agree conditions are very good for ice growth.. both in extent and thickness and health?

NWS of Alaska show SST temps of 6 degrees and up to 10 in the Chuckchi! Whereas Bearing has widespread 7s and 8s.. SSTs are expected to drop off quickly apparently as a low brings very cold temps and lots of snow..

[Cymro]

Ice seems to be building up n icely this year and the extent seems alot more prolific than last years and numerous years before probz down to the early cold pooling that seems evident atm. As to the thickness etc last year secured some good deep streches of ice in the centre of the artic that haven't weekend much over the summer period this can only be amplifyed if cool conditions stay as they are.

[Gray-Wolf]

Ice seems to be building up n icely this year and the extent seems alot more prolific than last years and numerous years before probz down to the early cold pooling that seems evident atm. As to the thickness etc last year secured some good deep streches of ice in the centre of the artic that haven't weekend much over the summer period this can only be amplifyed if cool conditions stay as they are.

Could you please look at July/Aug MODIS images and then look at the drift charts (from the buoys on the north pole cam will do?) and tell me that the ice ,beyond 80N, is not 'weakened' please?