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pottyprof

Arctic Ice Discussion - 2010 Freeze Up

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With the refreeze of the Arctic now under way, what level of extent could we achieve given the late start to the season? When posting, please make sure you can back up your claims/details with links to relevant papers and articles. Links to blogs are acceptable provided they contain actual scientific detail and not just a personal view.

Enjoy the season. :drinks:

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I'll repost this paper as it's relevant to the way we witness refreeze this year;

fulltext.pdf

this is one of the things that hinder the 'recovery' so many folk are hungry for (along with lack of thickness/perennial, loss of ice arches/bridges across the exits from the basin, increased mobility of the pack etc.

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I'll repost this paper as it's relevant to the way we witness refreeze this year;

fulltext.pdf

this is one of the things that hinder the 'recovery' so many folk are hungry for (along with lack of thickness/perennial, loss of ice arches/bridges across the exits from the basin, increased mobility of the pack etc.

Seems like an interesting paper, a bit exhausted so only had a quick look through it (had a late night last night after the Bill Bailey gig in Dublin and lots of travel today!).

Smallest gain today in about a week, but still nothing too bad at 35,000km2. I know there are a number of reasons why the ice may have slowed down, but could the warm sst anomalies be a big part of it? They are cooling down quite a bit though...

Some relatively mild air pushing up over the Arctic basin through the Barents and Kara sea over the next few days, but plenty of cold air remaining over the Beaufort sea and the Canadian Archipelago so we may well see some big gains here.

post-6901-014931300 1285963448_thumb.png

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Gained just 9,000km2 yesterday.

The IJIS concentration images show small gains across much of the Arctic ocean but with a loss near the Beaufort sea, close to the warm SST anomalies. Perhaps a slight slowdown in gains until those anomalies can be pegged back enough to support ice cover...

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Gained just 9,000km2 yesterday.

The IJIS concentration images show small gains across much of the Arctic ocean but with a loss near the Beaufort sea, close to the warm SST anomalies. Perhaps a slight slowdown in gains until those anomalies can be pegged back enough to support ice cover...

I'm keeping out of the fray until Dec when we should have a better idea of how ice reformation is going.

I am surprised at the early finish to ice loss this year (pleasantly so) and a little worried by the optimism that some folk seem to be showing around the recent 'rebound' of ice levels as winter approaches.

I cannot reconcile the heating that must of occured across large areas of the Basin (where ice departed by May) and also the onset of the winter storms (we saw in the southern ocean just how disruptive storms can be to low ice 'desities/concentrations') and we are yet to face a major L.P. entering the basin via Fram/Greenland/Baffin or through Bering.

Anyhow, lets just sit back and watch the rebuild and how it shapes up once it enters the areas we know have been 'under sun' for most of the summer?

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GW what do you want to see perfect flat ice all connected as one big lump? come on.. its the beginning of the freeze season, ice normally has cracks in it.. besides a lot of the ice is 3-5 inches thick at the moment especially around the fringes.

The 80N temps are currenly dropping closer the average temps.. mush better so far than last year..

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On that point how much of the 'gain' from Baffin/C.A./Beaufort is Basin ice moving out? Greenland is obviously on a 'loss' moment and that has to be spread (as the image showing the north of Nares shows) leaving only the Basin and Laptev with 'gains'?

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On that point how much of the 'gain' from Baffin/C.A./Beaufort is Basin ice moving out? Greenland is obviously on a 'loss' moment and that has to be spread (as the image showing the north of Nares shows) leaving only the Basin and Laptev with 'gains'?

I think you are clutching here GW, this year defo did not go how you proposed even with a big El Nino.

BFTP

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I think you are clutching here GW, this year defo did not go how you proposed even with a big El Nino.

BFTP

I'm quite happy to admit that I'm missing 1/2 million sq km of melt (though I wouldn't say that makes me sad? relieved? yup) this summer and I could only point to July/Aug 'weather' as an explaination.

That said we have ended up down on last years figure and ,when you look to the melt areas there was only the area to the N.of Greenland that appeared 'unscathed' by the season (2 months of compaction kept the cover 'solid'). We lost all of the 'fast ice' along the coasts of the C.A. and saw an early 'drain' on the ice to the north into the NW Passage (and melt) as well as a rapid 'thaw' of the NW Passage itself. Mark Serezze made plain in 07' that we could expect an number of years of 'blocked NW Passage' as the area lost it's thick perennial from the channels and inlets and this process (to me) now appears complete. We will see next spring/early summer what impact this has on the NW Passage but I would expect an early opening (again) but a lot more ice from the basin using the passage as a 'drain' via the channels to the East of Melville Island.

As I've noted the area to the north of Greenland.C.A. held it's own this year (due to weather) but come a year of strong Beaufort Gyre/trans Arctic drift then this ice is in danger of rapidly flowing out of the basin via Fram,Nares and the C.A. The loss of this ice is key for the switch to a 'seasonal pack' and I believe we have been watching the final 'readying' for this process this year with the emptying of the C.A. of 'ice rubble' leaving clear channels and warmed waters. I'm still watching those 'free channels 'to see if they act like Nares this winter and continue to empty 'Basin ice' throughout winter. Should this occur it will hinder the development of F.Y. ice in the passage as the bergs 'ice break' their way to Baffin. I know you'll disagree with this potential so it'll be worth a watch to see if we have different behaviours of the ice there.

As for the coming winter freeze I'll need to see how the ice that had completely melted out 'reforms' and what thickness it attains (C'mon CryoSat2! we need your input!!!). We can use the buoy data to see how mobile a pack we have (10yrs ago it took 18months to cross the basin, in 08' it took 6 months for the buoys to do the same journey?).

Plenty to watch and keep an eye on! Let's not end up with the silliness we had in March/April last if we have another cold N.Hemisphere winter (in patches), we all know what happens to ice outside the basin come May/June ......no matter how much there is!

For those looking for 'recovery' I'd advise that you focus on the area N.Greenlan/C.A. and southern Beaufort sea. We need ice 4m+ to form an ice island at least 1/3 as big as the basin (I reckon) and no continuous flow of it out of Fram (like we saw last winter?).

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A very big chunck of sea ice moving through Nares at the moment. It's the biggest I've seen in there as long as I've been watching, and stands the best chance of blocking things up as long as it doesn't disintegrate!

post-6901-093843700 1286101039_thumb.gif

We'll have to wait and see how it copes with the island between Greenland and Ellesmere. Break or wedge?

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We'll have to wait and see how it copes with the island between Greenland and Ellesmere. Break or wedge?

We all saw what a 200ft thick Berg (4 times the size of Manhattan Island) did there 6 weeks ago and this will only be 13ft or so thick so I'll go for 'Break'.

EDIT:

http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/20101001TERR.jpg

http://ocean.dmi.dk/arctic/images/MODIS/Kennedy/20101002TERR.jpg

open and then flick between the images. Seems to be moving quite fast?

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I did mention last week that Sunday's figure might be revised upwards and this indeed was the case 4,813,594 on the 18th September appears to be the low point for this year (not certain but very likely). With the latest figures at 5,166,875, this figure is

308,750 below recent term averages, and 1,653,900 below longer term averages.

Ice Growth this week was Melt rates fell to 50,000 this week, this is above average.

So where did we finish

Above 2007 by 560k,

Above 2008 by 105k

but below 2009 by 435K.

and below every other year on record and around 1.95m less than the long term average.

I will do this again next week to confirm this is the year low figure.

As suspected the low point was reached and we are now entering the refreeze period.

With the latest figures at 5,633,125, this figure is 209,844 below recent term averages, and 1,644,426 below longer term averages. Ice growth this week was 62,000 per day, this is above average.

This is the last update using the summer spreadsheet. I will be creating an Autumn/winter one next week, but I will not be updating this throughout the winter period, but If someone wants to update it themselves, please do so.

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A gain of around 95,000km2 yesterday, which takes us just above 2009.

There seems to have been small gains all around the Arctic, with general improvemant in concentration. Looks like the northern passage is close to or already closed now too.

http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e

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Now this is what I call an exciting refreeze season, with the onset of a la nina, an earlier than expected refreeze but as posted above some serious lacking of ice in some areas, I have been following the arctic ice threads for a few years now and this to me is the most exciting so far excluding 2007 of course.

By the way great picture of the ice chunk moving through Nares, please keep us updated on what happens there.

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Plenty to watch and keep an eye on! Let's not end up with the silliness we had in March/April last if we have another cold N.Hemisphere winter (in patches), we all know what happens to ice outside the basin come May/June ......no matter how much there is!

For those looking for 'recovery' I'd advise that you focus on the area N.Greenlan/C.A. and southern Beaufort sea. We need ice 4m+ to form an ice island at least 1/3 as big as the basin (I reckon) and no continuous flow of it out of Fram (like we saw last winter?).

Surely it’s better to have a cold Artic winter with a good extent and more importantly a strong build of ice volume.

I appreciate it will only be single year ice but even so.

Had we had a slow refreeze would that not be cause for alarm ?.

To date we seem to be having the fastest re freeze this century, can’t be all bad ?

Haven’t 13 of the last 14 days been above average re re freeze (haven’t gone over all the stats so happy to be corrected)

You seem to suggest it’s almost irrelevant what this winter brings, as it will be business as usual come next spring.

I would be concerned if the refreeze was slow

Sure its from a low base and I am aware of all the implications.

However its a bit like saying to Yeovil Town when they go 1-0 up at Chelsea, you know your going to lose 8-1 don’t you why bother scoring a goal.

I would say enjoy the goal

I had gone for 6m by the 6th October , with a upward revision from yesterday , still likely

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I'm looking forward too spring for the all the silly doom and gloom posts about all ice the melting in the coming summer.

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I'm looking forward too spring for the all the silly doom and gloom posts about all ice the melting in the coming summer.

You know how much I'll enjoy 'cut and pasting' this come the 'perfect storm' Pit!

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I had gone for 6m by the 6th October , with a upward revision from yesterday , still likely

Yep, your guesses looking best at the moment. I presumed after an initial jump in extent that the warm SSTAs would slow down growth for a week or so, looks like I'm gonna be wrong though.

With temps like this...

compday.109.255.78.101.276.11.4.0.gifcompday.109.255.78.101.276.11.5.14.gif

... it's hard to see why we are having such a rapid re-freeze. I picked 1000mb temperature instead of surface to try eliminate some of the effect of the latent heat from freezing but it looks practically the same, I can only imagine it's effect must be must stronger than I'd thought.

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Hmmmm... the temperature maps I posted earlier have disappeared???

Anybody else having trouble accessing the modis images?

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Yep, your guesses looking best at the moment. I presumed after an initial jump in extent that the warm SSTAs would slow down growth for a week or so, looks like I'm gonna be wrong though.

With temps like this...

compday.109.255.78.101.276.11.4.0.gifcompday.109.255.78.101.276.11.5.14.gif

... it's hard to see why we are having such a rapid re-freeze. I picked 1000mb temperature instead of surface to try eliminate some of the effect of the latent heat from freezing but it looks practically the same, I can only imagine it's effect must be must stronger than I'd thought.

I could think of three reasons...

1. Its frickin cold up there

2. Perhaps a lot of the summer melt was just shallow melt pools which contain fresh water

which as we know freezes at 0c and being shallow would of course freeze quicker anyway.

3.The synoptics have been locking the cold in over the Arctic and not allowing warmer intrusions

into the Arctic since the 2nd and permanent freeze started.

probably much more complicated than this though, ie temps, wind, circulation, radiation cooling

salinity and differing sea temperature layers.

Someone posted a good link some where in the polar ice thread as to how Arctic ice is formed

I had a quick search but can not find it.

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... it's hard to see why we are having such a rapid re-freeze. I picked 1000mb temperature instead of surface to try eliminate some of the effect of the latent heat from freezing but it looks practically the same, I can only imagine it's effect must be must stronger than I'd thought.

We lost a lot of multi-year ice (5+ years, much thicker and fresher than 1st/2nd year ice) in the Beaufort this year. Maybe that meltwater freshened the near-surface layer? That would make it easier to freeze up again. Are there salinity charts available anywhere?

If this is the cause, look for next summer's first-year ice to be fresher and more resilient than "normal" first-year ice - although whether that means anything in the context of conditions that can melt 5+ year ice is another matter.

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We lost a lot of multi-year ice (5+ years, much thicker and fresher than 1st/2nd year ice) in the Beaufort this year. Maybe that meltwater freshened the near-surface layer? That would make it easier to freeze up again. Are there salinity charts available anywhere?

If this is the cause, look for next summer's first-year ice to be fresher and more resilient than "normal" first-year ice - although whether that means anything in the context of conditions that can melt 5+ year ice is another matter.

There is far more multi-year ice in the Arctic than there was even last year. As for the M.Y. ice

in the Beaufort area that went in 2007 i think.

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