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Espen

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The Aftermath
« on: April 16, 2013, 09:00:03 PM »
We are now on the road of no sea ice in the Arctic during the summer season, my guesstimates it will happen sometimes +/ 2016 (less than 500.000 km2), after that, I then believe this situation will continue for a short period where the sea ice free period will be extended mainly by starting earlier and earlier in the melting season.
As said I believe this is a interim situation, and I have problems to understand what will happen next, will the melting continue or will changing sea currents and/ or weather patterns level of thing?
Or will it all end in a Ecopocalypse© (Freewayblogger) , and in what form?
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OldLeatherneck

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Re: The Aftermath
« Reply #1 on: April 16, 2013, 09:39:52 PM »
Espen,

I'm looking at the decline of Arctic sea ice to occur in the following stages, although brighter minds may want to add additional step functions:

Stage 1 - Ice Free September
Stage 2 - Ice Free June - September
Stage 3 - Ice Free Perennially

I just realized as I typed the word "Stage" it sounds like a cancer diagnosis wherein the earlier stages are treatable and the final stage is terminal with no means of recovery.  Cancer has been on our minds recently as my wife's co-worker just lost her husband to cancer (<4 weeks from first signs of pain until death).
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Espen

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Re: The Aftermath
« Reply #2 on: April 16, 2013, 09:58:02 PM »
OldLeatherneck;

I agree with your stage theory, at least the 1. and 2. but I am not so sure about the 3. stage, especially because I see some imbalances in the energy balance, resulting in major changes in Sea Currents, but how that will end up, is a?
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ChrisReynolds

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Re: The Aftermath
« Reply #3 on: April 16, 2013, 10:51:49 PM »
Old Leatherneck,

With reference to this:



PIOMAS volume broken into less than and greater than 2m thick in March.

I'd like to suggest:

XXXX - 2006 Phase 1. Removal of old ice volume.
Slow but gradually increasing rate of change in area / extent.

2007 - 2010 Phase 2. Consolidation post 2007 with continuing loss of old ice.
Step drop in summer extent, step increase in annual range.

2011 - XXXX Phase 3. Period of increased volatility in which the bulk of the final ice volume loss occurs.
Continued loss of old ice, step drop in thicker older ice. New record tie for 2011, new record for 2012, new record for 2013? Increased area and volume losses during the melt season (June to Sept and April to June respectively).
Period of increased volatility of ice due to thinner ice and greater ease with which new open water can be formed.

Type of transition to first ice free year, not known at present:
A Rapid crash to zero? or
B Tail, existing for some years after rapid ice loss event ends, causing a cessation of trend in summer minimum volume loss.?
But I see Phase 3 as containing the bulk of the transition volume loss.

Reasons for A.
Increased ice/ocean albedo effect.
Increased melt ponds, and attendant albedo increase due to FYI.
Increased ridging during summer due to thinner ice.
Increased brine rejection causing enhanced ventilation and ocean heat influx.

Reasons for B.
Decreased incident solar radiation at end of season close to the pole.
Effect of abyssal deep below the ice in the centre of the pack.
Increased heat loss in autumn/winter.
Increased growth of FYI in response to lower sea ice minima (this should level out at over 20k km^3 volume = 10M km^2 (area of ice in Arctic ocean) * 2m (current equilibrium thickness (approximate) of first year ice).

There are more reasons, I suspect these are the main ones.

Phase 4. Consolidation of seasonally sea ice free state. Gradual increase of ice free period length determined by winter thinning and ocean warming as the period of ice free gains more energy (ice albedo).

I don't think it's possible to go into the perennially sea ice free until the cloud response is better understood. Research during phase 4 should provide enough information to help with that issue.

crandles

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Re: The Aftermath
« Reply #4 on: April 17, 2013, 01:51:27 AM »
A Rapid crash to zero?
Increased ridging during summer due to thinner ice.

Is there much ridging during summer and will it increase?

I would have thought that more or less ridging in winter would be a more significant factor. Reduced thickness would mean there isn't as much momentum to pile the ice up as high. Kinetic energy might be higher with reduced mass but increased speed while strength is reduced, but I struggle to see this having much albedo effect.

ChrisReynolds

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Re: The Aftermath
« Reply #5 on: April 17, 2013, 07:45:34 AM »
Perhaps ridging wasn't the best term, the issue is: Thinner ice in summer more easily reveals open water under wind forcing. This is suggested in a paper, but I can't recall which one.

Espen

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Re: The Aftermath
« Reply #6 on: April 17, 2013, 08:02:53 AM »
Chris;

I believe very much on the over nite theory, meaning a plunge down to zero in a very short unexpected period, that is what have experienced with both sea and lake ice over the years, and I don't see that should be much different here.

But when we reach zero? How will both the Atlantic and less the Pacific behave, we already now see the Atlantic reaching further north than a few years ago, will that momentum be conserved? How about the various currents Golf etc.?

And I don't think we will have a year around ice free state, for years to come, but relatively thin and vulnerable sea ice  will be the standard of Arctic Winter Sea Ice.
« Last Edit: April 17, 2013, 08:49:22 AM by Espen »
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fishmahboi

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Re: The Aftermath
« Reply #7 on: April 17, 2013, 08:38:35 AM »
Would transition A not bring us to a perennially Arctic Ice Free extent depending on how early it occurs?

anonymous

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Re: The Aftermath
« Reply #8 on: April 17, 2013, 01:07:08 PM »
There is a Zhang et al paper using PIOMAS as data source and comparing sea ice dynamics of the period 2007–2011 to 1979–2006 in terms of ridging, drift/export, internal forces, mechanical strength and of course concentration/volume.


The authors mention that in summer sea ice reaches more and more a state of 'free floating'.  When I look at the drift pattern which established during recent anti cyclones I have the impression Beaufort Gyre and Transpolar Drift got combined into a single huge drift scheme starting in the Beaufort and ending in Fram Strait. I still fail to stop my imagination seeing major flush out events.

Jim Williams

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Re: The Aftermath
« Reply #9 on: April 17, 2013, 01:33:10 PM »
I think that if it is ice free in June then it is ice free all year.  The Arctic basically becomes part of the Atlantic.

Laurent

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Re: The Aftermath
« Reply #10 on: April 17, 2013, 02:08:12 PM »
I am afraid that is a very highly possibility !!!
Like a submarine emerging :

We already see the atlantic in the arctic north of Spitzberg.

ChrisReynolds

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Re: The Aftermath
« Reply #11 on: April 17, 2013, 06:41:27 PM »
Would transition A not bring us to a perennially Arctic Ice Free extent depending on how early it occurs?

If it remains significantly below zero over winter the heat imbalance between the ocean and air will still draw heat out of the ocean and cause freezing. The resultant ice will then thicken at a rate determined by the temperature difference between air and ocean. Under current conditions the thickness created is about 2m, it would require significant winter warming to reduce this thickness. Note that this is how thick the ice can get in one autumn/winter season.

This thickness determines the volume of ice that then needs to be melted before there is so little ice that one could say the ocean is effectively ice free. At 2m thick the peak volume in the Arctic Ocean is of the order of 20k km^3.

frankendoodle

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Re: The Aftermath
« Reply #12 on: April 17, 2013, 06:57:34 PM »
Great question Espen.
Lets picture our first ice free arctic summer. For 4-5 months the latitudes 70N to 75N will be open ocean absorbing 90% of the suns rays 24-7 and lats 75N to 80N for about 3 months. Even if the remaining areas are open only for a few weeks, the heat absorbed will be staggering.
When the sun goes down for 6 months that heat (a lot of it) will be released in the form of water vapor and a relatively thin ice crust will form. I cannot see how this won't make all the air and sea currents north of 40N go haywire.
Having said that, I don't know if their will be enough ambient heat to keep the arctic totally ice free for a long time. The geological records show the ice caps stick around still CO2 levels are at about 1000ppm and we are only at 400. I can see winter ice forming later and later while melting earlier and earlier, but we are talking about a region that is devoid of direct sunlight for half an annum.
Feel free to differ with me :)

ChrisReynolds

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Re: The Aftermath
« Reply #13 on: April 17, 2013, 06:58:01 PM »
Espen,

I can't find a good reason to go for either a tail or a crash.

With regards examples from lake ice, or other oceans. Firstly the bathymetry of the Arctic Ocean may play a role, it is possible that as the ice edge becomes restricted to the abyssal deeps that remaining summer ice will prove more difficult to get rid of.

Arcticio,

Thanks for that paper, I was unaware of it. Contrary to your fears, in the conclusion it is stated: "The effect of the reduction in ice volume export is to slow down the decline of Arctic sea ice." That's an increase in area export (faster ice movement), but the export is of thinner ice, so net export is reduced.

Crandles,

I've only just read the conclusions of the paper Arcticio linked to, but it's worth looking at. It seems my point regards "Thinner ice in summer more easily reveals open water under wind forcing" might not be the way PIOMAS is behaving. Although it's been a long day and I'm bushed.

Espen

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Re: The Aftermath
« Reply #14 on: April 17, 2013, 07:26:01 PM »
Chris;

Yes I am aware of that sea ice from the Arctic is very different than ice from elsewhere, mainly due to difference in age and thickness, and that is why I have a limit of 500.000km2 to compensate for that, there will be ice floating around in that part of the world for years to come, we will have icebergs from glaciers and other ice remains cruising around, but I still believe the sea ice will disappear "over nite" (overall) and it will then make headlines, and not only in this forum!

I will not be surprised if even regulars from this forum will be surprised!
« Last Edit: April 17, 2013, 07:54:48 PM by Espen »
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anonymous

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Re: The Aftermath
« Reply #15 on: April 17, 2013, 07:42:19 PM »
Contrary to your fears, in the conclusion it is stated: "The effect of the reduction in ice volume export is to slow down the decline of Arctic sea ice." That's an increase in area export (faster ice movement), but the export is of thinner ice, so net export is reduced.

Chris, my imagination is about the future, elsewise I think there is a medical term for that... :)

ChrisReynolds

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Re: The Aftermath
« Reply #16 on: April 17, 2013, 08:10:01 PM »
Espen,

Wouldn't surprise me, although I still don't see a convincing physical reason for it happening this year. I think that we need to see a succession of new record lows and a continuing loss of winter peak thickness.

Arcticio,

I'm sceptical of all the ice exiting, but not of a massive loss given the right winds.

Espen

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Re: The Aftermath
« Reply #17 on: April 17, 2013, 08:12:19 PM »
Chris;

Don't get me wrong, my estimates when that will happen is still 2016 latest.

And why 2016? It is because the cross sum is 9! ;)

According to scientific rules, you know! :-[
« Last Edit: April 17, 2013, 08:38:36 PM by Espen »
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theoldinsane

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Re: The Aftermath
« Reply #18 on: April 17, 2013, 09:13:43 PM »
Hello. First time poster...

One thought I have is that it will be more rainy weather up there which increases the melting.

Increasing open water area and warmer air will increase evaporation and thus it will rain more during the summer. The rain causes increased melting because the rain water comes into direct contact with the already melting ice and transfers heat to the ice.

 Just a wild thought, maybe, but with the following questions:

 1 Is this a relevant mechanism?

 2 If so, is this a positive feedback of any significance?

 3 If so, is this  addressed in any previous blog post?

 This is an important forum! Thanks

Espen

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Re: The Aftermath
« Reply #19 on: April 17, 2013, 09:56:25 PM »
theoldinsane;

Welcome to the site! :)

Yes rain is always a factor when it comes to ice melt, whether it will be a decisive factor?
I believe rain will have more importance over Greenland in the future, but then we are talking GIS ice!
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OldLeatherneck

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Re: The Aftermath
« Reply #20 on: April 17, 2013, 11:50:08 PM »
Would I be correct in assuming that the narrow channels in the Canadian Archipelago will continue to freeze over in winter, long after the Arctic Ocean is essentially ice-free perennially??
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Bob Wallace

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Re: The Aftermath
« Reply #21 on: April 18, 2013, 12:51:33 AM »
"The effect of the reduction in ice volume export is to slow down the decline of Arctic sea ice." That's an increase in area export (faster ice movement), but the export is of thinner ice, so net export is reduced.

Shouldn't we be looking at the vol. exported/max. yearly vol.?  At the percentage of the year's maximum that is leaving via the Fram.  The net export could be slowing but the role of export could, at the same time, be increasing.

Pmt111500

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Re: The Aftermath
« Reply #22 on: April 18, 2013, 02:18:26 AM »
Would I be correct in assuming that the narrow channels in the Canadian Archipelago will continue to freeze over in winter, long after the Arctic Ocean is essentially ice-free perennially??

I'd say look at Nares, it of course has the fastest current of the channels AFAIK. If the sea ice behaves like the channels on some lake systems and Nares there would be ice developing on slowly streaming sections. And yes, shallower bays and channels freeze faster. On Baltic, it has looked to me (no articles though) like everything under about 20m deep freezes way faster, unless there's a current running under developing ice. I don't know the depths of CAA channels, and the water is saltier than in the Baltic. I know a few who do ice fishing on Baltic and they've been saying the longer route is quite often the safer one.
« Last Edit: April 18, 2013, 02:24:13 AM by Pmt111500 »

Vergent

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Re: The Aftermath
« Reply #23 on: April 18, 2013, 02:48:49 AM »


Bob

They are 150m to over 300m deep, except along Canada proper, where there are some shallows. If they get warm, they will be hard to freeze.

V


anonymous

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Re: The Aftermath
« Reply #24 on: April 18, 2013, 03:08:46 AM »
I'm sceptical of all the ice exiting, but not of a massive loss given the right winds.

I wish I had a decent weather model, I would treat it round the clock to show me whether that's possible or not.

Pmt111500

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Re: The Aftermath
« Reply #25 on: April 18, 2013, 06:47:39 AM »

They are 150m to over 300m deep, except along Canada proper, where there are some shallows. If they get warm, they will be hard to freeze.


Good map! Trying to draw some currents and down/upwelling areas on that. Suggesting a cold water upwelling area might form in the ice free arctic at the CAA end on Canada basin (NW Ellesmere). This would supply coldest possible waters to the channels crossing the northern archipelago (North of Parry Channel), so I'd guess they would be iced over for longer than Nares. Southern CAA looks more like the Baltic with respect to channel width and depth and likely has a bit fresher water for the river runoff so crossing the iced over straits there would require much local knowledge like currently in Baltic.

crandles

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Re: The Aftermath
« Reply #26 on: April 18, 2013, 12:57:48 PM »
Perhaps ridging wasn't the best term, the issue is: Thinner ice in summer more easily reveals open water under wind forcing. This is suggested in a paper, but I can't recall which one.

Thank you Arcticio for the link to the paper.

A 3% decline in ridging isn't much for 33% decline in volume, so that seems to be a small effect (particularly in summer when there is practically no ridge ice formation)

Quote
Ice speed (cm s1) 7.7 8.7 13
Ice deformation rate (yr1) 16.0 18.7 17
Ridged ice production (1012 m3yr1) 4.82 4.68 3
Ice volume export (1012 m3yr1) 2.76 2.34 15

Ice speed is up 13% but volume export (all exits not just Fram) is down 15% due to that 33% volume reduction. So it seems the ice is spreading out more when it is thinner and faster speed means more area exported even though volume exported is down. That sounds like added area of open water in the Arctic meaning more albedo feedback which sound like your extra "open water under wind forcing".

Perhaps your B list should include decline in volume export as volume reduces. OTOH I suspect channels into CAA might open up more to FYI than to MYI so the 15% decline in volume export for 33% volume decline per PIOMAS may not continue into future.

ChrisReynolds

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Re: The Aftermath
« Reply #27 on: April 18, 2013, 09:28:12 PM »
It wouldn't be unreasonable to add that factor under list B.

I wonder if it would be worth trying to put the factors, and any we can add in order of magnitude?

crandles

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Re: The Aftermath
« Reply #28 on: April 19, 2013, 12:07:10 AM »
It wouldn't be unreasonable to add that factor under list B.

I wonder if it would be worth trying to put the factors, and any we can add in order of magnitude?

To rank the order, ideally we want a calculation of not only size of effect but also size of uncertainty. To do that we would presumably have to agree a metric. (2012 min volume - new Volume at min due to effect being considered) per year?

Any such calculations would seem to be a good idea but I fear quite a few could leave me stumped and more would have wide error ranges.

Probably have to split into different categories. For example:

1. Albedo of thinner ice
2. Albedo of FYI vs MYI
3. Open water formation efficiency effect on albedo
4. GHG level effect on thermodynamic equilibrium thickness at maximum
5. Ocean upward heat flux effect on thermodynamic equilibrium thickness at maximum
6. Ocean upward heat flux effect on melt volume during melt season
7. Change in export volume
8. Change in ridged ice production volume


Things like
Decreased incident solar radiation at end of season close to the pole.
Effect of abyssal deep below the ice in the centre of the pack.

may change the shape of the curve but do they change what happens this year compared to last year in terms of volume?

Given the volume is practically the same as last year, I would say that 1. to 8. above are virtually zero effect except for 2 and 6. 6 is probably a big unknown. It would be interesting to know how big an effect 2 has.

One third more heat absorption has been mentioned. That seems rather large to me but ... well never mind for the moment. How does that, with the increased area of FYI this year convert to effect on volume at minimum?



Bob Wallace

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Re: The Aftermath
« Reply #29 on: April 19, 2013, 05:56:15 AM »
From the Zhang, et al. paper....

1979 - 2006
Ice volume 20.5
Ice export 2.76
Pct. vol. exported 13.5%

2007 - 2011
Ice volume 13.7
Ice export 2.34
Pct. vol. exported 17.1%

While export volume has dropped, export seems to be playing a larger role in reducing the amount of remaining ice.  An anti-tail factor.

crandles

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Re: The Aftermath
« Reply #30 on: April 19, 2013, 11:59:33 AM »
While export volume has dropped, export seems to be playing a larger role in reducing the amount of remaining ice.  An anti-tail factor.

A different view based on a different metric which sounds quite sensible.

The effect seems based on faster ice speed due to thinner ice but that is outweighed by thinner ice means less volume.

2.76 to 2.34 is a change of 0.42 with the maximum volume changing from 29.4 to 23.9. To get to ice free needs max volume to fall from 21.9 to about 18.8. So a further change of 3.1 in max volume with the change considered in paper being about 5.5. So 3.1/5.5 = 56% of the change considered in the paper would be needed to reach ice free conditions. So ice export volume would fall another 0.24 K Km^3.

That won't increase the 3.1 needed fall in max volume as much as 0.24 because of albedo feedback, so knock off about 21% so maybe a 3.3 further fall in max volume is needed rather than 3.1. (.24*.79/3.1) About 6% further from ice free due to this effect seems to be my interpretation.

If there is a tail because max volume only falls at a much slower rate then this looks like an addition that lengthens the tail. If max volume falls rapidly then it is only a small effect.

I think this could get very confusing with lots of different ways of doing the calculations. (Hopefully 6% seems small enough to avoid too much argument.)

Bob Wallace

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Re: The Aftermath
« Reply #31 on: April 19, 2013, 07:09:54 PM »
Quote
"The effect of the reduction in ice volume export is to slow down the decline of Arctic sea ice."

If the percent of remaining ice exported is rising then the decline caused by export must be accelerating.

Additionally, the ice now being exported is thinner, meaning more surface area is being lost which decreases albedo/increases ocean warming.

ChrisReynolds

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Re: The Aftermath
« Reply #32 on: April 19, 2013, 07:51:19 PM »
Bob,

Thanks, good point, it doesn't need any change in the net export for it to play a greater role against declining volume.

This however should only work up to a point. With sufficient winter cold the ice will continue to grow to 2m thick, which as I say implies an Arctic Ocean volume of around 20k km^3. Even if ice is exported during the winter any open water revealed by its loss will be taken up with new growth. However as we've seen this winter (the NSIDC graphic done by someone from Environment Canada), there's been substantial loss of MYI due to export. We've still got a fair residual of MYI to get rid of before we reach a seasonally sea ice free state.

So perhaps rather than look at total volume, if we look at volume of MYI, the factor you outline is having even more of an effect.

Vergent

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Re: The Aftermath
« Reply #33 on: April 19, 2013, 08:12:03 PM »
Quote
"The effect of the reduction in ice volume export is to slow down the decline of Arctic sea ice."

If the percent of remaining ice exported is rising then the decline caused by export must be accelerating.

Additionally, the ice now being exported is thinner, meaning more surface area is being lost which decreases albedo/increases ocean warming.

When the CAA opens up we may be losing more through there than we do through the Fram.



Last year, the Fram losses were relatively thin. But the CAA losses were thick ice.

V


Bob Wallace

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Re: The Aftermath
« Reply #34 on: April 19, 2013, 08:36:08 PM »
If I did the math right the area of ice lost in 2007 to 2011 is slightly higher than in 1979 to 2006.  About 9% higher.  That's what we might expect if the more shallow keel of thinner ice allows it to better ride the flow of wind-driven water closer to the surface.

As we get the thicker MYI flushed out we may see the outflow of area increase even further.

And while winter-exported FYI ice may be replaced, it will be replaced with thinner (less time to freeze), more easy to export ice.

Bob Wallace

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Re: The Aftermath
« Reply #35 on: April 19, 2013, 08:42:08 PM »
Quote
When the CAA opens up we may be losing more through there than we do through the Fram.

I think that is a distinct possibility.  The question is which is going to be the most efficient melting zone.  Will it be the large water area, Greenland Sea, which is receiving heat from the Atlantic or will it be the abundant land mass which is losing its snow cover earlier and absorbing a lot of heat?

If the CAA can't melt inflow fast enough then it will get clogged.

TerryM

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Re: The Aftermath
« Reply #36 on: April 20, 2013, 06:26:54 AM »
I've always assumed that anything that gets as far as Fram Strait is lost. The Greenland Sea is just a lineup of old ice shuffling on to it's watery grave. I don't think the channels of the CAA are going to plug up this year & I think that Nares Strait will be open full throttle even if PII2012-1-A remains grounded in Kane Basin.


Without Lincoln Sea or the area north of the CAA being able to hold MYI the only safe haven may be north of Ellesmere or north of Greenland near Kap Morris Jesup. Both of these locations have currents drawing the ice into areas of no return. Fram Strait or Nares Strait for the ice over Kap Morris Jesup & Sverdrup or Peary Channel for the ice above Ellesmere.


Ice that escapes the CAA will be forced into the balmy waters of Beaufort, so no respite in that direction. I think there are just too many exits open for what MYI is left to have much chance at settling in for another season.


As recently as 2011 a paper was published pushing the idea that the thick MYI above the CAA would take decades to melt out even after the rest of the ice had left the stage. - then 2012 happened. I'm not comfortable with tipping points, but do believe that a step was descended when the CAA went from providing refuge to providing a graveyard for some of the really geriatric MYI.


Nothing but speculation on my part, but I don't see any place left for the old ice to sit and recuperate without being chased out into one death zone or another. The Arctic has always been a harsh environment for those too old to pull their own weight. Instead of old Inuit being persuaded to end it all by drifting away on a floe, this time it's the old ice being asked to leave the camp.


Terry