Arctic Ice Discussion (The Melt)

[Gray-Wolf]

"If anyone of you can show me a peer reviewed paper which shows conclusively that we understand (and have evidence for our understanding) what the radiative budget is for the Arctic region, then I'll happily eat my words. I admit I haven't paid much attention to the debate for some time now but the last time I looked no one had figured out the huge conundrum of albedo, radiative cooling, open water and cloud production (more or less, whether positive or negative feedback), small particle pollution, ocean cycles, atmospheric pressure patterns etc etc etc."

This, from J', had been troubling me and so after I'd 'Father Ted'ed' him to sleep last night I 'U Tubed' on his XBox around the subject and was very surprised to find multiple recent lectures, from various 'arctic symposiums', by lead researchers in all the disciplines bringing the latest research to the meetings.

Ice albedo feedback; it's there , it's real, it's quantifiable and it's massive. there seemed to be a glut of research after the 07' melt esp. for the Beaufort sea area. They found the only way to explain the massive increases in basal melt, both in that year and since, was the energy being absorbed by the open water. The interaction with the atmosphere (weather) could explain 20 to 40cm of melt but the warming of the ocean took out 2m plus of ice.

We have been discussing the open water inside the basin this year. from what i learned last night our fears are most justifiable. With the areas open already, on both the Canadian/Alaskan side and the Russian side, and the record thin ice beyond the open water we look set to see the whole of this side of the basin open by seasons end. this would appear significant as this will then attack the ice further east (pole toward Fram). with an ability to gobble 2m plus of ice in 07' (waters opened up much later) the thick ice along the Greenland coast could see some damage/thinning?

We also have the low ice levels in Barentsz and Kara. these have been open since the start of the season so ,again, you'd expect a great potential to take any ice 2m thick or less (most of our side of the basin).

Then we go on to the research done of the interaction between open water and the atmosphere. Again it would appear that we have plenty of data and lots of evidence for the way the late summer/early autumn Arctic is impacting N.Hemisphere circulation via it's impacts on the jet stream. There was a lot of talk of 'stuck' weather patterns, drought ,flood,cold,heat and the increase in such events. it would appear that whilst not able to pin 'AGW' to any one event more 'global weirding ' events occur today than do 'natural variation' events.

Grand solar Min.; apparently no time soon? The best 'estimates give a min of 40years away and a max of 200years away (having just come off the grand max). With the current rate of change to our world any such event would not even return us to todays 1c global increases.

I didn't bother looking at the current research on methane releases. I was so bloomin' depressed to find out just how bad things truly are I chickened out.

Anyhow, these lectures (and the data provided) are easily found. Happy hunting!

[jethro]

Any chance of links to peer reviewed papers GW? U tube crashes my computer.

[BornFromTheVoid]

A little interesting animation of the sediment from the Mackenzie pouring out under the sea ice and into the Beaufort see in the last week.

Click on it for a larger image.

[knocker]

Pity can't access this paper from the Potsdam Institute.

Multistability and critical thresholds of the Greenland ice sheet

Recent studies have focused on the short-term contribution of the Greenland ice sheet to sea-level rise, yet little is known about its long-term stability. The present best estimate of the threshold in global temperature rise leading to complete melting of the ice sheet is 3.1 °C (1.9–5.1 °C, 95% confidence interval) above the preindustrial climate¹, determined as the temperature for which the modelled surface mass balance of the present-day ice sheet turns negative. Here, using a fully coupled model, we show that this criterion systematically overestimates the temperature threshold and that the Greenland ice sheet is more sensitive to long-term climate change than previously thought. We estimate that the warming threshold leading to a monostable, essentially ice-free state is in the range of 0.8–3.2 °C, with a best estimate of 1.6 °C. By testing the ice sheet’s ability to regrow after partial mass loss, we find that at least one intermediate equilibrium state is possible, though for sufficiently high initial temperature anomalies, total loss of the ice sheet becomes irreversible. Crossing the threshold alone does not imply rapid melting (for temperatures near the threshold, complete melting takes tens of millennia). However, the timescale of melt depends strongly on the magnitude and duration of the temperature overshoot above this critical threshold.

http://www.nature.com/nclimate/journal/v2/n6/full/nclimate1449.html

[BornFromTheVoid]

Lowest on record for the time of year by over half a million now...

http://arctic.atmos....nteractive.html

[stewfox]

Heat escapes during the re-freeze. It's true that increased ice loss (lower summer minimum) leads to increased heat escape (more ice formed during re-freeze). This means that the annual cycle gradually gets wider, with more ice loss in the summer followed by more ice re-forming in winter. But these effects are not equal and opposite. If they were, then the winter maximum would stay constant. It hasn't: there is a downward trend in the maximum as well as the minimum - for volume in particular as MYI gets replaced by first-year ice, but also for extent and area.

Can you show me any evidence of a downward trend in the maximum extent area ??

More ice of course is reforming in the winter as more is lost in the summer. You could argue a slight reduction but no downward trend

http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

[songster]

Can you show me any evidence of a downward trend in the maximum extent area ??

More ice of course is reforming in the winter as more is lost in the summer. You could argue a slight reduction but no downward trend

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

http://tamino.files.wordpress.com/2012/03/bymonth.jpeg

NSIDC ice data: complete series plotted for each month. As you can see, there is a clear downward trend for every single month of the year, although the trend is more pronounced in summer months. The Antarctic has an upward trend, which is much smaller, and is (if I recall correctly) not significant for most months.

[BornFromTheVoid]

Can you show me any evidence of a downward trend in the maximum extent area ??

More ice of course is reforming in the winter as more is lost in the summer. You could argue a slight reduction but no downward trend

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

Yearly maximum extents here

[Methuselah]

I think that the downward trend is obvious, and has been for some time. So, surely our task is to try and explain the why?

[Geordiesnow]

I think the main reason for the maximum extent to decrease a bit is simply because of the persistant below average ice we get in the Barents Sea, most other areas do tend to reach average extents regardless how low the summer extents have been in recent times. I mean last winter for example, the Bering Sea was above average, the Labrador sea was also above average and even the Sea of Okhotsk recorded near enough average extent by March, but per in recent times, the Barants sea was way below the average. I think this tells me in general, regardless how low the extent may go, I doubt it will have a major impact on the maximum extents unless local weather conditions stop ice from forming e.g the Kara Sea this past winter.

Regarding the hear and now, I'm not too shocked to see the extent fall sharply, the Bering Sea ice was always going to melt and anyone who been following the sea ice during the winter will know large parts of the Kara Sea struggled to refreeze and when it did properly refreezed during March, the ice was always going to melt out quickly, I did predict we may see a record low extent come the end of May because of this but the ice held on a little longer in both the Kara and Bering Seas than I thought.

The concern for me is the large open water in the Beaufort Sea and the general state of the ice in the Laptev Sea, I still think we may end up near the 2010 figure if weather conditions become and remain favourable. Even Joe B has now predicted the ice extent could finish very close to the 2007 extent and we know he is the biggest cold ramper/believer in sea ice recovery there is.

Should be an interesting melt season for sure.

Edited June 16, 2012 by Geordiesnow

[BornFromTheVoid]

You can get the regional sea ice extent data from 79-2010 here, handy for regional analysis.

EDIT: Of course, cheers Songster

Edited June 16, 2012 by BornFromTheVoid

[songster]

You can't put a trend on those without removing the seasonal cycle first (e.g. by calculating the daily anomaly before doing the trend analysis. Otherwise your trendline gets misled by the fact that the data series is starting just before a peak and ending just after a trough.

[Filski]

Lowest on record for the time of year by over half a million now...

http://arctic.atmos....nteractive.html

Early prediction, along the lines of the lateness of the maximum extent reached, is that this will level off soon and probably not set a record minimum but still be one of the lowest 3 or 4 yrs on record. Since 2007 in particular this seems to be a trend, unless I'm imagining it: late maximum extents are followed by early rapid melt with a gradually reduction of rate. It looks pretty bad now but will be back with the group by late august if not earlier.

Of course that fact that each new 4-5yr period we pass sets a new lowest 4-5yr period is of concern. Seasonal ice free arctic is some way off though.

[knocker]

I dunno, using the Jakobshaven Ishbrae glacier as an example of Greenland mass loss is a bit sneaky. The rate of retreat with that particular glacier has recently been extremely fast and highly anomalous. It would be like using the Karakoram glaciers as an indication of glacial change in the Himalayas (but I guess, for the opposite purpose).

Possibly a fair comment but from a study in 2008.

The recent dramatic melting and breakup of a few huge Greenland glaciers have fueled public concerns over the impact of global climate change, but that isn't the island's biggest problem.

A new study shows that the dozens of much smaller outflow glaciers dotting Greenland's coast together account for three times more loss from the island's ice sheet than the amount coming from their huge relatives.

In a study just published in the journal Geophysical Research Letters, scientists at Ohio State University reported that nearly 75 percent of the loss of Greenland ice can be traced back to small coastal glaciers.

Ian Howat, an assistant professor of earth sciences and researcher with Ohio State's Byrd Polar Research Center, said their discovery came through combining the best from two remote sensing techniques. It provides perhaps the best estimate so far of the loss to Greenland's ice cap, he says.

[BornFromTheVoid]

On CT we've now reached 600,000km2 lower than the next lowest on record, quite surprising to be this low already.

Anyway, attempt number 2 at getting the regional sea ice trends.

This time I averaged the monthly anomalies into yearly anomalies, and just plotted them and added the trend line, so here they are.

Bering Sea

Sea of Okhotsk

Barents & Kara

Arctic Ocean

Hudson Bay

Canadian Archipelago

Greenland Sea

Baffin Sea

And finally, St Lawrence

[Gray-Wolf]

Thanks (yet again!) for your efforts BFTV!

I wonder what the mechanism is to make Bering 'buck the trend' of the rest of the basin? Is it it's position outside the basin I wonder? With our side of the Basin having the N.A.D. keeping things toasty does it reflect the increasingly common 'polar displacement'/'stuck weather patterns' we are increasingly understanding to be linked with low sea ice over summer?

[PeteG]

Thanks (yet again!) for your efforts BFTV!

I wonder what the mechanism is to make Bering 'buck the trend' of the rest of the basin? Is it it's position outside the basin I wonder? With our side of the Basin having the N.A.D. keeping things toasty does it reflect the increasingly common 'polar displacement'/'stuck weather patterns' we are increasingly understanding to be linked with low sea ice over summer?

I would think its mainly down to geography. With Alaska and Siberia to the east, west and most of the north, and with the Aleutian Island chain to the south it's virtually an enclosed sea.

Any wind from other than Sw to Se is going to be coming off a very cold land surface which will help the preservation of the ice, and the southerly winds won't be able to push much "warm" water into the Bering Sea because the Aleutians will tend to break up the flow. Also southerly winds will push the ice northwards against the coast and the the Bering Strait, consolidating the pack rather than breaking it up.

[BornFromTheVoid]

The Bering sea ice could be influenced by the PDO. So if we count the PDO as having turned negative in 2007, and do the same plot then for 1979-2006, we actually get a slight, though probably not statistically significant, negative trend.

So there is a chance of the -ve PDO having an effect.

Edited June 17, 2012 by BornFromTheVoid

[Gray-Wolf]

Thanks's Guys!

I know of the 'ice factory' situation where constant s'lys across the straight help ice form, and then blow it into the sea (with the same process happening behind pushing ever more ice south into the sea), but wonder if there is any process to facilitate a positive 'upward skew' on the plot when all others are significantly negative?

For me (and I mean 'for me') it shows that the latter part of the series is more impacted by the 'ice factory' than earlier and PDO does not skew that for me with PDO stuttering into neg. in 98/99? (PDO phases are only really called at their end seeing as we know so little about how to 'spot' the switch t'witch neg./pos.).

The last paper i saw on the PDO phases noted that since the 90's AGW had impacted the phases so I'm pretty firm on the 'switch' being 98/99 but that 'old' measures' would not pick up on the modern change.

Though I've now seen presentations encapsulating data since the onset of the Sat. era I only know of papers using 02' to 10' to show Arctic amplification as an impact of northern hemisphere circulation patterns. As such i can only suggest that the 'early phases' of this were felt mainly locally and only recently has vthe impact been expressed across the hemisphere? We know for sure that the 'blocked pattern' had an influence this year but what of 2010 etc.?

PS. Does not Nares look just about to 'bust out'???

http://lance-modis.eosdis.nasa.gov/cgi-bin/imagery/single.cgi?image=crefl1_143.A2012169184000-2012169184500.250m.jpg

Edited June 17, 2012 by Gray-Wolf

[jethro]

The Bering sea ice could be influenced by the PDO. So if we count the PDO as having turned negative in 2007, and do the same plot then for 1979-2006, we actually get a slight, though probably not statistically significant, negative trend.

So there is a chance of the -ve PDO having an effect.

Relevant to the above....

http://159.226.119.10/uploadpdf/wanghj_csbe_2006a.pdf

http://nldr.library.ucar.edu/repository/assets/osgc/OSGC-000-000-002-030.pdf

http://climate.gi.alaska.edu/researchprojects/hartmann%20and%20wendler%202005.pdf

http://www.arctic.noaa.gov/essay_bond.html

[Gray-Wolf]

Relevant to the above....

http://159.226.119.1..._csbe_2006a.pdf

http://nldr.library....000-002-030.pdf

http://climate.gi.al...endler 2005.pdf

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

As relevant as a Megalania to a monitor Lizard Jethro?

When all the studies focus on the 'old Arctic' and the 'old PDO' how can you draw any meaningful conclusions? (unless you need a cast iron 'Papers' and not refutable ongoing research conclusions presented at reputable Scientific AG M's?)

Truely apples and pears here J'!

[jethro]

As relevant as a Megalania to a monitor Lizard Jethro?

When all the studies focus on the 'old Arctic' and the 'old PDO' how can you draw any meaningful conclusions? (unless you need a cast iron 'Papers' and not refutable ongoing research conclusions presented at reputable Scientific AG M's?)

Truely apples and pears here J'!

Oh for goodness sake.

BFTV was wondering about whether or not the PDO has an influence, the papers I posted show and describe the known mechanisms. They're not making any comment on AGW, nor drawing any conclusions about the current state of the Arctic.

It is still possible to post in here about what's known isn't it? Or is the thread to be purely limited to amateur speculation?

And what do you mean about the 'old PDO'? Have the history books been re-written on that too?

[Methuselah]

Oh for goodness sake.

BFTV was wondering about whether or not the PDO has an influence, the papers I posted show and describe the known mechanisms. They're not making any comment on AGW, nor drawing any conclusions about the current state of the Arctic.

It is still possible to post in here about what's known isn't it? Or is the thread to be purely limited to amateur speculation?

And what do you mean about the 'old PDO'? Have the history books been re-written on that too?

That was the very same question I was about to ask, J...I wonder if the early signs of 'Modern Winter' Syndrome are beginning to appear?

[BornFromTheVoid]

Cheers for the links Jethro.

Just a thought, but not everything that passes the peer review system is true and established. I've read through numerous papers on the Arctic of supposed cycles in regional ice variations, over varying time scales and with quite flimsy theoretical mechanisms for how these come about, very few stand the test of time.

Thus the first paper which find the AO leads the PDO with a lagged 7 year correlation seems... I dunno, a little hopeful? You can generally find correlations between anything if you play with the numbers for long enough

The second paper is interesting, but hasn't passed peer review as far as I can tell, but it would still be interesting to see if the black carbon variations could actually have a visible effect on the sea ice on an annual time scale...

The 3rd paper, after a brief glimpse, appears to make sense anyway. Though it does bring in the question of why the change to a +ve PDO in '77 could have an immediate effect on global and regional temperatures, yet 6 years in to the -ve PDO and we're being told by some to wait because of the lag effect?

I think with the current "discussion", we need to be aware that the Arctic sea ice has undergone a significant change in thickness and nature in the last 6 years, and so correlations and relationships that may have worked in the past may now need to be modified. They don't need to be discarded completely, but were not dealing with the thick, strong and consolidated ice pack of the 70s, 80s and, to a lesser degree, the 90s and early 00s, so it's only logical that the sea ice will behave differently now to how it did "back then".

[jethro]

Thank you for taking the time to read them.

Off the top of my head thoughts....I don't know about the lag of the PDO, personally I'd be happier to accept either a lag or an instant impact if we knew what drove it in the first place. Theories abound on what drives the PDO from Solar, wind, through to atmosphere and link-up with other ocean currents. Perhaps there are many reasons and depending upon which coupling takes place, the time for effect may be instant or lagged?

I don't buy the argument of current ice conditions making a difference. For sure, ice loss may be exacerbated or influenced by the PDO but I have seen no evidence to suggest it is changing the PDO or any other ocean current. From a seasonal perspective, a larger expanse of open water may influence the weather but taking into account that re-freeze is rapid and the temperature up there drops quickly once darkness descends, any impact from this would be transitory.

As for the carbon issue, I've previously linked to papers about the impact of this (a few weeks ago), can't remember who did the studies but they have been done and peer reviewed. I know there are issues with peer review, not least that findings are revised once new information becomes available but that's the nature of the topic we're discussing. We can only work with what the current science tells us and that's got to be better than our unresearched musings.