Polar Ice

[noggin]

In my earlier post I forgt to ask this question......

What would be so calamitous about an ice-free Arctic?

[Guest North Sea Snow Convection]

Moderator shouldn't this be moth balled ,no reference to Arctic Ice at all ?.

The point regarding the 'first time in human history', is often used by alarmist (they mean the last 30yrs)

The post clearly was on OT and the paragraph you selected was just a related follow on thought from what she had said. As you know perfectly well.

There is no compelling evidence that the arctic ice variations are strictly due to man made causes.

[cyclonic happiness]

In my earlier post I forgt to ask this question......

What would be so calamitous about an ice-free Arctic?

I've been wondering whether the arctic being less icy in the summer, has had the effect of shoving the jet stream further south?

Of course this would lead to colder winter here as the jet has less far south to go and end up with mainly blocked winters?

During the little ice age, did the arctic have less ice during the summer?

[Gray-Wolf]

If you are me you'd expect nature to have a counter balance to any major ice loss across the Arctic (to keep things in a set climate pattern) so that only a 'real need' to step change to the 'warm setting' triggers the 'switch'.

That said the past 3 years may well have reflected that last ditch effort to save our current climate setting but ,if the pressures remain, and continues to grow in strength and impact, then there will be the 'step change' to another climate type.

I think the 'ice free' Arctic is a major marker in this step change to a 'warm climate' as it maintains a warming cycle even if 'natural cycles' attempt to pull global temps down (all that extra energy that is absorbed by the Arctic waters once 'open water' emerges needs to be 'offset' by the 'natural' to merely 'stand still').

This time we appear not only to have natural 'Earth based' cycles trying to 'cool' the climate but also a low energy Solar too. As we see from the past few years temps have not been greatly impacted around the globe esp. in the 'oceanic' southern Hemisphere.

As far as impacts when we loose the Ice we already have an 'Ice Free Arctic' thread discussing just this.

[SteveB]

I must say it's a relief to see the ice concentration not in free-fall, seems to have levelled out and settled into the pack.

Lets see where it goes from here.

http://www.ijis.iarc...aice_extent.htm

Edited May 15, 2010 by SteveB

[masheeuk]

I must say it's a relief to see the ice concentration not in free-fall, seems to have levelled out and settled into the pack.

Lets see where it goes from here.

http://www.ijis.iarc...aice_extent.htm

Thank you for talking about the actual level of ice rather than trying to brow beat people with your opinion. I did wonder if anyone else was looking at what the figures are saying

[Gray-Wolf]

I think we've seen a number of folk looking at both the ice volume anom figure;

The ice areas figures;

and the sea ice extent figures;

and the MODIS images;

http://rapidfire.sci...altime/2010134/

and wondering just how low things can go this year.

Some , on the other hand , may just look at the polecam;

http://www.arctic.no...gallery_np.html

see ice, and say "all is well....."

EDIT: Ian Simond's team had this to say;

"While itself a consequence of climate change, the shrinking Arctic ice cap has contributed to a "positive feedback loop" in which global warming and loss of ice reinforce each other on a regional scale.

"The sea ice acts like a shiny lid floating on top of the Arctic Ocean, reflecting most of the incoming sunlight back into space," Screen explained by email.

But when the ice melts, more heat is absorbed by the darker water, which in turn heats the atmosphere above it.

"What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise," he said.

From 1989 to 2008, global temperatures climbed on average by 0.5 Celsius, whereas the Arctic has warmed by 2.1 C - the most rapid increase of any place on the planet.

Up to now, scientists have sharply disagreed on the main causes of this discrepancy.

Using the most recent observational data from the European Centre for Medium-Range Weather Forecasting, Screen and co-author Ian Simmonds uncovered a nearly perfect season-by-season match during the 20-year period analysed between surface warming trends and reductions in sea ice cover.

The findings show that the main driver of so-called "polar amplification" - warming in excess of the global average - is shrinking ice cover and not increased cloudiness or changes in ocean and atmospheric circulation, as others have argued.

Models used by the UN's top scientific authority, the Intergovernmental Panel on Climate Change (IPCC), seriously underestimated the recent loss of Arctic sea ice, Screen pointed out.

"They may also underestimate future sea ice loss and warming, but only time will tell for sure," he added.

At the end of northern hemisphere summer 2007, the Arctic ice cap shrank to the smallest size on record, 40 per cent below the average 7.23 million square kilometres observed in 1979-2000, according to the US National Snow and Ice Data Centre (NSIDC).

The sea ice pack thawed to its second smallest size in 2008, followed by the third smallest in 2009.

NASA satellite data has also shown that Arctic sea ice has thinned considerably.

During the period 2004-2008, the ice diminished in thickness by some 67 centimetres."

© 2010 AFP

http://news.smh.com....00429-tsr3.html

Edited May 15, 2010 by Gray-Wolf

[Solar Cycles]

Thank you for talking about the actual level of ice rather than trying to brow beat people with your opinion. I did wonder if anyone else was looking at what the figures are saying

I agree, this and all things regarding Arctic ice, I tend to give a wide birth. Probably as a result of certain peoples OTT rants, and wishes!

[Gray-Wolf]

I must say it's a relief to see the ice concentration not in free-fall, seems to have levelled out and settled into the pack.

Lets see where it goes from here.

http://www.ijis.iarc...aice_extent.htm

???

I still see a normal rapid decline in sea ice? Do you know something I don't? By June , at this rate ,we will also be the bottom of the pile?

[BornFromTheVoid]

???

I still see a normal rapid decline in sea ice? Do you know something I don't? By June , at this rate ,we will also be the bottom of the pile?

Well, I think that after 2 weeks of rapid falls in ice up to the 11th, SteveB was referring to the 3 consecutive days of well below average loss up to 14th. Of course, yesterday we saw another very large fall which if it continues would be a problem.

Guess we need a little more time to see whether the melt is easing a little or the 3 below average days were out of place.

[Gray-Wolf]

Well, I think that after 2 weeks of rapid falls in ice up to the 11th, SteveB was referring to the 3 consecutive days of well below average loss up to 14th. Of course, yesterday we saw another very large fall which if it continues would be a problem.

Guess we need a little more time to see whether the melt is easing a little or the 3 below average days were out of place.

OK, and ,seeing as we are now in the first major phase of melt nothing is to be gained from a 'running commentary' on each day I guess. As I've said (and it would appear 'repeatedly') the real crunch comes in late July/through Aug to see how the surviving pack then fares once the ice which would normally melt over a season has gone.

Through June and early July it might prove useful to see how the pack is positioning itself for this 'late phase' (whether it is a central rotating ice island or whether it is tending to stream towards the 'exits' from the basin).

Thanks for clearing that up by the way ! , I was a tad confused.

[Thundery wintry showers]

In my earlier post I forgt to ask this question......

What would be so calamitous about an ice-free Arctic?

It would have serious potential to disrupt the atmospheric circulation patterns in a very big way, and lead to a strengthening of the positive feedback mechanism over the Arctic, i.e. absence of ice promotes higher temperatures which promotes absence of ice.

The melting of the Arctic ice cap would not contribute to sea level rises, but melting of the Greenland ice sheet certainly would, and a warmer and ice-free Arctic would promote a much-increased rate of melting of the Greenland ice sheet. Sea level rises would inundate our coastal areas and cost billions of pounds in flood defences.

Also for snow lovers an ice free Arctic would mean significantly reduced amounts of cold air to tap into so we'd get a much-increased incidence of northerlies and easterlies in the middle of winter bringing rain and 5C.

As for the reasons for the recent changes in the Arctic- I've seen nothing to change my view that most of it is down to natural forcings, but also that the rise in global temperature over the last 50 years has added to them.

[Argyllcraig]

Not too sure if this is the right place to post this question but here goes.

What effect does volcanic activity have on the Arctic Ice pack? My assumption would be particularly this year that we may see some additional ice melt as the result of soot from the icelandic activity and the dirty effect it has on the ice and the extend to which it then absorbs sunlight.

My main thrust however is from under water volcanic activity and could a phase of increased activity beneath the arctic be having a noticeable impact on ice melt particularly along the northern section of the midatlantic ridge fault line over the last few years?

[Gray-Wolf]

Not too sure if this is the right place to post this question but here goes.

What effect does volcanic activity have on the Arctic Ice pack? My assumption would be particularly this year that we may see some additional ice melt as the result of soot from the Icelandic activity and the dirty effect it has on the ice and the extend to which it then absorbs sunlight.

My main thrust however is from under water volcanic activity and could a phase of increased activity beneath the arctic be having a noticeable impact on ice melt particularly along the northern section of the midatlantic ridge fault line over the last few years?

Firstly I'd like to agree broadly with TWS's take on any interruption to our 'weather maker' and it's 'normal functioning'. I'd also like too add that I to see 'natural variability' as the a major drivor in the ice loss we have seen but would go further to add that our 'impacts' have had an 'added effect' that may well prove essential in what we witness today.

Insofar as volcanic influence is concerned ,we are seeing predominantly northly airflows driving the ash plume south (and not North) so 'ash' over the north is not an issue.

The lack of SO2 from this eruption would also mean that any 'cooling' from this tiny eruption is minimal........wait for Katla if you want to see 'impacts' on a global scale!!!

Edited May 16, 2010 by Gray-Wolf

[4wd]

It would have serious potential to disrupt the atmospheric circulation patterns in a very big way, and lead to a strengthening of the positive feedback mechanism over the Arctic, i.e. absence of ice promotes higher temperatures which promotes absence of ice.

The melting of the Arctic ice cap would not contribute to sea level rises, but melting of the Greenland ice sheet certainly would, and a warmer and ice-free Arctic would promote a much-increased rate of melting of the Greenland ice sheet. Sea level rises would inundate our coastal areas and cost billions of pounds in flood defences.

Also for snow lovers an ice free Arctic would mean significantly reduced amounts of cold air to tap into so we'd get a much-increased incidence of northerlies and easterlies in the middle of winter bringing rain and 5C.

Muddying the difference between loss of sea ice and highly improbable Greenland ice sheet melting is mischievous.

Also implying that there would be differences in winter conditions in Europe is rather silly.

There will always be a very large area of sea ice through winter.

There would only ever be a very short period of the year when ice could be largely absent and that is late in the summer when solar input is rapidly diminishing at high latitudes.

I don't think it will make any real difference at all to weather patterns or long term albedo.

It's also likely that open water would lose a good deal more heat from the deeper ocean than ice capped water due to convective circulation.

Edited May 16, 2010 by 4wd

[MR EXTREMES]

Firstly I'd like to agree broadly with TWS's take on any interruption to our 'weather maker' and it's 'normal functioning'. I'd also like too add that I to see 'natural variability' as the a major drivor in the ice loss we have seen but would go further to add that our 'impacts' have had an 'added effect' that may well prove essential in what we witness today.

Insofar as volcanic influence is concerned ,we are seeing predominantly northly airflows driving the ash plume south (and not North) so 'ash' over the north is not an issue.

The lack of SO2 from this eruption would also mean that any 'cooling' from this tiny eruption is minimal........wait for Katla if you want to see 'impacts' on a global scale!!!

and katla is a concern.

[Thundery wintry showers]

Muddying the difference between loss of sea ice and highly improbable Greenland ice sheet melting is mischievous.

Also implying that there would be differences in winter conditions in Europe is rather silly.

There will always be a very large area of sea ice through winter.

There would only ever be a very short period of the year when ice could be largely absent and that is late in the summer when solar input is rapidly diminishing at high latitudes.

I don't think it will make any real difference at all to weather patterns or long term albedo.

It's also likely that open water would lose a good deal more heat from the deeper ocean than ice capped water due to convective circulation.

A bit too simplistic and optimistic there I'm afraid.

If the Arctic sea ice is lost in summer then summers will, on average, warm up because of albedo effects (less ice = less reflection of sunlight, so presuming that long term albedo won't change much is wide of the mark). Therefore on average summers in the Arctic will be considerably warmer. Therefore we are likely to see increased warming over Greenland because there will be more warm air/less cold air to tap into. Increased warming at the warmest time of year means more melting.

There was no attempt to imply that an ice-free Arctic means an ice-free Greenland- melting of such a colossal amount of ice will take time even in the improbable event that temperatures jump by several degrees- but even just one-third of the ice sheet melting may contribute to significant sea level rises.

There is nothing "silly" in the implication about changes to winter conditions in Europe. The refreezing of ice requires energy, and large positive temperature anomalies tend to persist in areas where the ice refreezes much later than usual. Ice forming later means less time for the Arctic to cool down once the ice has formed, before the stronger sun in spring starts to raise temperatures again. If there is less cold air to tap into then our northerlies and easterlies will be less cold and more likely to give sleet or rain rather than snow. Last winter showed that we're still a long way short of being unable to get cold snowy winters, but add another few degrees of warming to the Arctic and it may be a different story.

Convective circulation may well cool open water but open water will always be warmer than ice sheets- or else it would freeze.

[Gray-Wolf]

The last time we had a 'seasonal pack' was 600,000yrs ago (or so the records appear to show) and ,at that time, 1/3 of Greenland was ice free.

Recent DNA evidence from the base of ice cores show Forrest's and grasses (kinda like Sweden today) across the lower third of Greenland. I don't know what implications are for sea levels if we lose this much of the ice sheet but I'd bet they would be around the '6m higher' mark that we had when temps were this high last time?

Sorry to hark back to it but any 'thermal mixing' of the Arctic Ocean will only serve to smash the halocline layer even more and it is this layer that enables 'thick ice' to both form and maintain. Once we lose this unique horizon we lose the chance of building thick perennial and so the chance to return to the 'old Arctic'.

It would appear that the 'old Arctic' did not rely on temps alone to maintain a summer ice presence but also upon the special zoning that the ocean developed whilst under protective ice cover. This would also hint at lower temps not being the only thing needed to allow a recovery of summer persistent ice across the Basin.

Could this be the final act in a 'normal' thaw from the last ice age? is this how the Arctic Ocean acts if an interglacial lasts long enough? Whilst the glacial epoch continues we will probably always grow ice at the pole in winter but once the Arctic ocean is again as mixed as the other world oceans will it ever be able to hold a summer pack like we used to have without needing another glacial epoch to rebuild the halocline layer to it's former depths first?

[Yorkshiresnows]

A bit too simplistic and optimistic there I'm afraid.

If the Arctic sea ice is lost in summer then summers will, on average, warm up because of albedo effects (less ice = less reflection of sunlight, so presuming that long term albedo won't change much is wide of the mark). Therefore on average summers in the Arctic will be considerably warmer. Therefore we are likely to see increased warming over Greenland because there will be more warm air/less cold air to tap into. Increased warming at the warmest time of year means more melting.

There was no attempt to imply that an ice-free Arctic means an ice-free Greenland- melting of such a colossal amount of ice will take time even in the improbable event that temperatures jump by several degrees- but even just one-third of the ice sheet melting may contribute to significant sea level rises.

There is nothing "silly" in the implication about changes to winter conditions in Europe. The refreezing of ice requires energy, and large positive temperature anomalies tend to persist in areas where the ice refreezes much later than usual. Ice forming later means less time for the Arctic to cool down once the ice has formed, before the stronger sun in spring starts to raise temperatures again. If there is less cold air to tap into then our northerlies and easterlies will be less cold and more likely to give sleet or rain rather than snow. Last winter showed that we're still a long way short of being unable to get cold snowy winters, but add another few degrees of warming to the Arctic and it may be a different story.

Convective circulation may well cool open water but open water will always be warmer than ice sheets- or else it would freeze.

I'm not to sure about the above TWS.

The sun's ability to heat ocean water in the arctic is pretty poor (due to the angle of the suns rays, only really impacting for two to three months at most). There is then also the added complication of heat loss to the atmosphere (this is in fact part of the global thermocirculatory system ... heat gained in the tropics is circulated via ocean currents to Northern areas of permament heat loss.

Temperatures in the arctic over winter months will always fall very low due to the permanent night, and ice will always form in the winter months........ unless global warming really sky-rockets.

I'm also not so sure about the arctic's perceived global refrigeration role ....... it has been ice free (summer months) in the past (at least there is very good anecdotal evidence) and yet this has not led to runaway warming. I suspect that as you say, it is more to do with ocean currents and cyclic changes that dictates the amount of summer ice retention.

The PDO has been in a positive phase since 1979 and ice in the arctic has been on a more or less downward spiral since then. The last negative phase was from around the late 40's when ice extent increased (30's and early 40's were also bad for arctic ice cover). PDO is now mooted to have moved into its negative phase, so I guess we will need to wait and see what happens next ?

Y.S

[Gray-Wolf]

What we need to nail down is this notion of variability of sea ice Y.S.

I'm sure we all agree that ice extent varies, according to the many varied drivers, and that in the past the 'long cycle' phases (like the PDO) have lead to increases/decreases of ice cover over decadal timescales. None of this is in question.

Have we ever had sea ice so depleted in the past (in the past 600,000 yrs that is) as we see today. You, amongst other posters, seem to feel that it has and that , this being the case, the current Arctic Ice loss is nothing alarming.

I feel very differently about the situation.

I believe that science is telling us that we have NOT had such a depleted pack before (in the span of human existence) and that the wrecking of both the halocline and the 'old perennial' has placed the Arctic in it's current 'death spiral' (as some would put it) with no way for a 'recovery' to occur without the depth of cold,fresh water (halocline layer) across the surface of the ocean. If this layer formed under the conditions present at the height of the last glaciation how do we expect it to reform during an interglacial? what does this mean for the Arctic Ocean?

I feel it means that ice thickness will be pegged at current values, I think this is why the ICESat DAT showed such a uniform thinness in the pack from 04 to 08 (Kwok, et al) and that this years IceBridge and Cryosat2 data will show a continuation of this 'thin' ice trend.

If 2nd and 3rd year ice can now only manage that 2m+ depth (as occurs in the well mixed 'southern ocean' each southern winter) then we will always have a seasonal pack in waiting for the foreseeable future.

As for any change in the 'energy' the Earth receives. 12.64 w/m sq is what we get at the pole come solstice. With an intact pack 90% and more bounced straight back into space. With dark water now available 80% of that energy is absorbed. You feel this 'negligable' , I feel this addition, to a previously balanced system, important.

I do not believe in 'runaway warming', the planet is too clever to allow that, I do believe in a 'step change' to a warmer carbon cycle setting (as we have had in our geological past) and that is what I fear we are living through.

[4wd]

As for any change in the 'energy' the Earth receives. 12.64 w/m sq is what we get at the pole come solstice. With an intact pack 90% and more bounced straight back into space. With dark water now available 80% of that energy is absorbed. You feel this 'negligible' , I feel this addition, to a previously balanced system, important.

I do not believe in 'runaway warming', the planet is too clever to allow that, I do believe in a 'step change' to a warmer carbon cycle setting (as we have had in our geological past) and that is what I fear we are living through.

At Solstice there won't be much open water at all - the only time there might be more will be late August/September.

The minimum is always just before the onset of rapid re-freeze.

Someone way back was bemoaning the likelihood of sudden collapse in area and remains being flushed out "this year".

And yet also we're being warned about how impossible it must have been for all the ice to have ever been lost before.

You can't have it both ways, either the pack is rather difficult to melt and flush or it can happen fairly quickly over a decade or two of reductions - in which case it's highly likely to have happened countless times in this 600,000 year history (not sure where that timespan came from but Hey Ho...)

[stewfox]

It would have serious potential to disrupt the atmospheric circulation patterns in a very big way, and lead to a strengthening of the positive feedback mechanism over the Arctic, i.e. absence of ice promotes higher temperatures which promotes absence of ice.

The melting of the Arctic ice cap would not contribute to sea level rises, but melting of the Greenland ice sheet certainly would, and a warmer and ice-free Arctic would promote a much-increased rate of melting of the Greenland ice sheet. Sea level rises would inundate our coastal areas and cost billions of pounds in flood defences.

Also for snow lovers an ice free Arctic would mean significantly reduced amounts of cold air to tap into so we'd get a much-increased incidence of northerlies and easterlies in the middle of winter bringing rain and 5C.

As for the reasons for the recent changes in the Arctic- I've seen nothing to change my view that most of it is down to natural forcings, but also that the rise in global temperature over the last 50 years has added to them.

I dont think anyone (apart from AL Gore and a few die hard alarmist) are suggesting that the artic will remain ice free in the winter !

Worse senario 4-6 weeks in the summer where the artic is effectively free of ice , even then it will probably only mean the whole of the artic is navigitable by pleasure boat rather then it being ' free of ice'.

That doesnt mean the whole of the Greenland ice sheet will melt and Florida will see 150ft sea rises.

Not fully understood wether it would be 'bad' to have a few weeks of artic free ice apart from the development of some decent cruise opportunities and potetntial environmental impact that could bring.

Edited May 17, 2010 by stewfox

[Gray-Wolf]

At Solstice there won't be much open water at all - the only time there might be more will be late August/September.

The minimum is always just before the onset of rapid re-freeze.

Someone way back was bemoaning the likelihood of sudden collapse in area and remains being flushed out "this year".

And yet also we're being warned about how impossible it must have been for all the ice to have ever been lost before.

You can't have it both ways, either the pack is rather difficult to melt and flush or it can happen fairly quickly over a decade or two of reductions - in which case it's highly likely to have happened countless times in this 600,000 year history (not sure where that timespan came from but Hey Ho...)

The 'perennial pack' is the key to this and yes it is a very difficult thing to melt out.

It appears it takes over 50 years of sustained melting to achieve it (and probably over 100yrs, which includes the period prior to the globally 'dimmed' period from 1940 through 80).

The workings of a 'thin pack', and the ease that this can be lost, are wholly different.

We are now entering the period of 'thin ice' as the perennial has now collapsed.

[Gray-Wolf]

As an 'add on' to the above watch the way thar Beaufort sea area behaves this melt season.

It is currently well fragmented and the buoy data has the ice on the move and heading for the 'ice free' area across the front of the Bering Straights. This would include the perennial that has been forming there over the past 2 years (if we still call this 'thin multiyear' perennial) so let's see how it performs in a normal melt season once out of 'protective' waters?

EDIT: Incoming solar and dark water.

It does not have to be across the geographic pole, those are just the 'max' figures. Look at the SST anoms across the open water of Barents already this year and see how far these anoms spread over the season. How do you figure drift ice will cope if it finds itself driven into such high SST's? East Siberian Shelf sea has also posted high sst anoms over the past years so let's also keep our eyes over that side of the Basin this year.

For those hoping that the 'late ice' would fare better check the SST's outside of the Bering straights.

Edited May 18, 2010 by Gray-Wolf

[songster]

Yes, very worrying. I wish I could find out how unusual this is. Unfortunately the historical images from that site are uninformative as the historical image set uses a different mapping from extent -> colour. On the daily gif, yellow indicates a concentration of ~85%, while on the historical gifs, everything from 85% up appears as subtly different shades of magenta. Looking at http://igloo.atmos.u...5&sd=11&sy=2010 for example (comparison of extent for May 11th 2007 / 2010), there seems to be not a lot of difference. Those subtle shadings could be concealing a world of hurt though.

Looking at this in a bit more detail, check out the 30-day animation available here

http://arctic.atmos.uiuc.edu/CT/animate.arctic.color.0.html

There's a patch north of Svalbard that drops down to ~85% between 12th-15th April before heading back up towards ~95%. Note that the full moon was on the 14th, so that looks to me like the ice cover shattering due to the spring tides. Just under four weeks later, on the 7th May, the extent in this area drops rapidly again, this time drops down to ~75% before slowly coming up again. It's still weakened now and hasn't got back up to the 95% level 11 days later.

I'm going to stick my neck out and say that this region's going to start looking very ropey indeed around the June new moon, maybe below 70%.