« Crowd-Source Prediction of Minimum Arctic Sea Ice | Main | Party like it's 1989 »

Comments

Feed You can follow this conversation by subscribing to the comment feed for this post.

Kevin McKinney

Thanks for bringing this forward, Neven. Interesting (and as so often, somewhat disquieting.)

When I used to live in snow country, I often saw point #4 in your list vividly illustrated on the streets of Sault Ste. Marie--exposed bits of dark, refrozen street slush, heavy with dirt and grit, would often create their own little 'melt pockets' when exposed on the southern face of a snow bank. And the overall melt process really tends to bring them to the surface, visibly lowering albedo.

Shared Humanity

If a polar high sets up over Greenland this summer, would the clockwise winds bring anomalously warm temperatures to the CAA, Northwest Greenland and the last remaining mass of thick MYI?

David Vun Kannon

That last map of the 30-day temperature anomaly might make us breathe easier about Greenland ice, but it doesn't make me feel any better about the Arctic ice! The huge positive anomaly over the East Siberian Sea is like taping a "Melt Me" sign on the back of snowman.

David Vun Kannon

Neven, thank you for adding the Greenland maps to the ASI Graphs page. I'm not sure how complicated your update process is for that page, but it would be very nice to see the monthly updates to the albedo reflectivity instead of the static chart you currently link to. I don't want to sound ungrateful - the page is great and one of my regular morning routines is to visit it.

Neven

Thanks for reminding me what that thing was that I forgot to put in the post, David! I also prefer automatically updated images and thought this was the address for it (and that it just needed to be updated). If you have a link for me I'd be very grateful.

colincr

A little perspective...

From Neven's first paragraph, "a record mass loss of over 500 GT", but for "simplicity" let's use just the 500 GT (and assume English rather than Imperial units). That equates to 1e15 (1 Quadrillion) pounds. Now, if we assume the [ahem] "average" weight of a single human (accounting for newborn babies as well as the morbidly obese) is 150 lbs, then an equivalent mass of human flesh would require ~6.67 Trillion humans or nearly 1,000 times the current population of the entire planet. 'Nuff said.

wayne

Lack of snow may be in part due to sublimation from the disappearance of inversions, a state of change of the basic structure of the temperature profile to adiabatic helps sublimation a great deal.
Its warming not measured by thermometers, but warming nevertheless seen by lack of snow.


On the sea ice near Greenland front in middle of the CAA, it melts still about 10 hours a day. While I wait for the first 12 hour melt period, I have just recorded a complete phase change from underside freezing to warming in one hour. http://eh2r.blogspot.ca/

I recommend this new way to study sea ice thermal properties very much to all. It reveals pretty much everything about how much the next minima will be.

Craig Merry

@ Shared Humanity: I would think so.

The albedo chart is really amazing. Let's hope the NAO stays positive.

Neven, like David, I check the graphs part of the blog nearly every morning to see what's up. Invaluable. Thanks!

NeilT

I spent years tracking Konrad Steffen's studies on Greenland so I'm fairly up on the melting.

However I didn't actually put all the figures together. If the Wiki Greenland page is correct, then the ice mass loss in the decade between 2002 and 2012 was equivalent to 7.2mm of sea level rise.

If 2012 became the norm, we would see that from Greenland alone every 6 years.

But as we've seen with the Arctic, there is no "norm", just constant acceleration. OK if we stick at 500 gt per annum then it will take 5,700 Years for the ice sheet to melt. But, then, the ice sheet was in balance in the 1990's and we lost 0.1% of it in the 2010's.

I'd say that only has to move to 1.0% by the 2030's and the human race is in serious trouble.

That looks like a real possibility today.

Hans Gunnstaddar

David wrote: “Neven, thank you for adding the Greenland maps to the ASI Graphs page. I'm not sure how complicated your update process is for that page, but it would be very nice to see the monthly updates to the albedo reflectivity instead of the static chart you currently link to.”

Just this past year NSIDC added a Greenland daily melt site. here is the link: http://nsidc.org/greenland-today/

The melt areas show up in orange. Not been very much so far, with some days showing dots of orange in the South. Today shows no melt. Should be interesting to go that site as the season progresses.

Chris Reynolds

Shared Humanity,

The high pressure over Greenland is a common feature of the summer, it's just that since 2007 it has been even more intense. Given that this intensification has occurred since 2007 it seems very likely again this year.

Measuring pressure over Greenland is problematic because the dome is so high. So it's more usual to measure geopotential heights, i.e. the height at which a given pressure level is found.

For 500mb pressure the following graph shows the changes in the height at which this pressure level occurs.
http://farm9.staticflickr.com/8361/8262014104_cab60552a7_o.png

Lord Soth

http://www.bbc.co.uk/news/science-environment-22486153

With C02 topping 400ppm for the first time in three to five million years, expect 2012 to become the new norm.

Ac A

Greenland Today shows surface melting is below average, actually it did not start yet. My bet is record from 2012 will hold for at least 1 year :-)

Alex

David Vun Kannon

Neven, As fas as I can see, the monthly updated chart gets a different location, therefore URL, every time. I didn't find a 'latest' URL that is static and always has the latest month. For example the latest chart is at
http://www.meltfactor.org/files/2013/05/0-3200m_Greenland_Ice_Sheet_Reflectivity_Byrd_Polar_Research_Center.png
which you can see will change every month. Perhaps we can ask Dr. Box to put the latest at a static URL.

Glacierchange.wordpress.com

There is not typically much melt by May 1 and if you look at the data from the ice sheet, limited melt until the end of May. This year the sensors at the K-Transect indicate the limited melt potential as yet. This has little to do with a potential melt record. In 2012 the first appearance of a melt lake in the Russell Glacier catchment was day 150. Last year this played out further north at Sarqardliup Sermia lakes too

Neven

David, I found this image I used for the ASIG,

http://polarmet35.mps.ohio-state.edu/albedo/0-3200m_Greenland_Ice_Sheet_Reflectivity_Byrd_Polar_Research_Center.png

, in this post from July 25th 2012. Because the 2012 trend line goes all the way to the end of the year, I surmised this is the link address that gets updated every once in a while. Also because it doesn't have a date in the ULR.

I'll drop a comment on Meltfactor.

Frankd 1977

574 GT of ice is about 637 km3 out of the 2,850,000 km3 of the total ice sheet. If this became the norm then Greenland alone would contribute 1.6 mm every year to GSL. That would mean a one inch rise every 16 years just from Greenland. Or 7 meters from the whole ice sheet.

wayne

Alex , "Greenland Today shows surface melting is below average, actually it did not start yet."

That is because we (CAA and West Greenland) are under the cold temperature North Pole scheduled to vanish in a few days.

I have just observed the first 12 hour underside melt in history today. http://eh2r.blogspot.ca/ . Despite the said colder temperatures. This leaves only one option, since beginning of May 2012 was Much warmer than beginning of May 2013 and since there has been consistently longer underside daily melting periods in 2013, only one reason for this to happen, the thermal signature of the sea is significantly warmer. Once the remainder of winter vanishes in a few days, top of Greenland will resume its recent course and will melt like last year.

[Test, N.]

Lewis Cleverdon

Neven - I'm puzzled by the general lack of discussion of the cryoconite issue as a potentially major factor in GIS albedo loss.

According to satellite imagery their darkening effect spreads uphill each spring over fresh snow, tracking the filling of the melt-lakes. An article on Japanese GIS research included the following:

- The Tokyo Institute of Technology and Chiba University have been observing cryoconites since the 1990s and have reported that they accelerate the speed at which ice melts.

Professor Nozomu Takeuchi of the Faculty of Science at Chiba University thought that "microbe populations may be growing in the polar regions due to warming," so he analyzed past satellite imagery of Greenland.

He says the area covered by the blackish ice has been spreading inland from the coasts over the years.

"There's no doubt the stains are from microbes. I think it's only a matter of time before they cover the entire ice sheet,” said Takeuchi, who has visited the ice sheet. “Changes in the ecosystem on the ice could significantly alter the Earth's environment." -

The first two links below are to images taken on July 4 & August 17 2010 by NASA's EO-1 of an area of SW Greenland centered on 68.91N & 48.54W, with the second two being enlargements of the ~6km lake in those images' upper left.

http://eoimages.gsfc.nasa.gov/images/imagerecords/80000/80677/greenlandponds_ali_2010185_lrg.jpg

http://eoimages.gsfc.nasa.gov/images/imagerecords/80000/80677/greenlandponds_ali_2010229_lrg.jpg

http://eoimages.gsfc.nasa.gov/images/imagerecords/80000/80677/greenlandponds_ali_2010185.jpg

http://eoimages.gsfc.nasa.gov/images/imagerecords/80000/80677/greenlandponds_ali_2010229.jpg

The degree of darkening shown is plainly not the uniform coverage that airborne dust and soot would provide, and it is emphasized by the contrast in the latter two images between exposed ice and ice shielded by meltwater that then drained away.

Given the year on year ascent of the melt-lakes accompanied by the cryoconites, how about a post on the prognosis for the latters' influence on the rate of GIS albedo loss and consequent melt-rate ?

Regards,

Lewis


Peter Ellis

Hi Wayne - could you let us know how you are observing this underside melt, and where you're based? This melt doesn't seem to be visible to any of the sonar buoys across the Arctic.

http://imb.crrel.usace.army.mil/newdata.htm

All of these show that the ice is is still thickening slowly, including 2013A which is quite far south within the Canadian Archipelago. The only exception is 2012L, which is in ~3.4 metre thick ice and so further thickening by congelation is not really expected.

Glacierchange.wordpress.com

Lewis I reviewed a paper two years ago that evaluated cryoconite in detail. They found that the organics despite making up only 5% of the dark material played an important role. Wientjes et al (2011)

P-maker

Lewis

Normally, I am not in favour of geo-engineering, but maybe now is the time to consider one such experiment.

The basic idea is, that two of the World’s superpowers – i.e. USA and China - have contributed quite substantially to the pollution of the Greenland Ice Sheet (GrIS) over the past couple of centuries. The US through forest fires and unlimited burning of coal and oil until the Clean Air Act in the 1980ies put a lid on the worst part of it. Since then, the Chinese have burned all the Australian coal, they could get their hands on. The Russians have been supportive letting massive forest fires add to the problem in recent years.

Atmospheric circulation patterns in the NH are quite stable, meaning that much of the US pollution has been deposited on the western side of GrIS, whereas China and the rest of the gang are responsible for pollution landing on the eastern slope of the GrIS.

My proposal – to help alleviate the accumulated albedo loss on the GrIS – would be to ask the armies of these two super powers to start cleaning up their mess. The idea would be to start early summer in the south – Americans to the left and Chinese to the right of the ice divide. A couple of thousand soldiers equipped with good old fashioned brooms and shovels should then start walking northwards as they clean the ice sheet from accumulated dust, black carbon and algae. The lower part of the ablation zone would be the most critical part to clean up, and they could just let the more dangerous ice streams - filled with nasty crevasses – slide into the ocean.

To avoid even more pollution from heavy duty diesel engines or traditional military aircrafts, the whole operation should essentially be done by foot soldiers. Who knows, the black carbon collected during this operation may turn out to be a valuable resource for lightweight aircrafts, boats or vehicles in the future. Other benefits include a cleaner ice sheet, higher albedo, less ice melt and slower sea level rise.

The experiment would have to stop by the end of summer due to harsh weather conditions. During the summer, scientists should be able to monitor albedo changes though satellites and ground-based observations. After a few years, we would know whether the whole operation has had any significant impact on the current ice loss rate. Maybe this type of experiment could be extended to the whole ice sheet and it could be repeated after a decade if albedo drops again.

Espen Olsen

Lewis;

"I'm puzzled by the general lack of discussion of the cryoconite issue as a potentially major factor in GIS albedo loss."

This issue was reported already reported in 1876 by Richard W. Coppinger on in his visit to Petermann Fjord:u

I quote: "The surface was thickly studded with circlar pits, about six inches deep, and from 1 to 18 inches in diameter, usually containing a little snow and some DARK powder of which I obtained specimens."

Part of the report can be seen here:

https://forum.arctic-sea-ice.net/index.php/topic,270.0.html

Lewis Cleverdon

Glacierchange - thanks for the link to the very interesting paper by Wientjes et al. I'm struck by the fact that while it cites four of Prof. Takeuchi's papers, it neither supports nor challenges his finding that the area of cryoconites is expanding.

Of the five main classes of contaminants identified, anthropogenic deposits appear a minor factor, with higher concentrations in the ablation zone - but since it is an ablation zone, is it not predictable that they would be more concentrated there than in the accumulation zone ?

Moreover, the clean white ice of emptied melt pools (with no visible dust streaks on the bottom of the bath) remains a stark contrast to surrounding areas where microbial activity has developed cryoconites, indicating that dust entrained in the ice is not itself a darkening factor, but in 'fertilizing' microbial ecologies it contributes indirectly to that darkening. Or am I missing something?

With regard to the expansion of cryoconite production, I wonder if you know of any research showing that the present darkened area has a particular entrained-dust signature that is not available elsewhere ? If there is no such limiting factor, then given unconstrained warming Takeuchi's expectation of an expansion across the GIS would appear logical.

Regards,

Lewis

Lewis Cleverdon

P-maker - you could do with checking the Royal Society's definition of geo-engieering before indulging your imagination.

You might also want to check the figures for cumulative emissions - those of the EU are way beyond China's.

Some geography study might be helpful too, concerning the area of the GIS, on which anthropogenic deposition appears to be a rather minor factor in current albedo decline.

With regard to your not being in favour of geoengineering, how many dark-skinned people need to be starving (and they will be first against the wall) before you think it's an essential expedient ? I'm looking for an order of magnitude here, not a specific number.

Regards,

Lewis

Lewis Cleverdon

Espen - I was aware of the Coppinger report from C19 but I hadn't seen a scan of it - so thanks for that.

I wonder just what other feedbacks' quiet acceleration has been ignored - given that the IPCC can't even report properly on the majors such as permafrost thaw, I suspect there will be more 'surprises' awaiting us.

Regards,

Lewis

Veli Kallio

I talk seldom as I find it today counter-productive to publish things and work with decision-makers at UN, EU & UK. Yet, I felt it necessary to write a note on this matter as I was nominated back in 2008 for international Nanak Peace Prize (sea level rise risks for global security and economic stability).

Firstly, the Negative Arctic Oscillations will continue and intensify much like sea ice will diminish and the snow line retreat will head to the north earlier than before. Almost each year from now on will show some sort of advance in melting (snow, sea ice, tundra or sea bed) to the previous years. Storms will be fiercer.

Secondly, the metamorphosis of Greenland's cold, dry, stable and moraine-forming ice sheet into warm, wet, dynamic and aggregate-forming ice sheet when summers will see Greenland surrounded by ice-free oceans.

The melt water from the surface percolates to the ice sheet base and transforms it into honeycombed, water-clogged ice that is slushy and unable to withstand pressure of the overlying ice layers. This eventually leads to Larsen B style rapid ice sheet failure as watery base oozes its way out and the overlying colder and dryer ice fractures forming huge ice islands. Heindrich Minus One (H-1) Ice Berg Calving then results, with the associated Last Dryas cooling as the ocean basin between America and Europe fills with ice debris.

Thirdly, the transformation of dominance of the "seasonal impact" moulins/crevasses into "accumulative impact" moulins and crevasses.

Until recently the ice melting occurred on the perimeter of Greenland where melt water and ice drains into ocean by the early autumn and takes the heat (thermal inertia of melt water) with it.

Although Jason Box criticised me that there exist no "accumulative impact" moulins on top of Greenland interior, I was able to find 29 sites that year in aerial survey.

Ice sheet is highly insular material and when melt water falls deep into ice, no heat can escape to the surface. As each summer adds water in subglacial ponds, or crevasses within ice, there is an absolute greenhouse effect in action with 100% retention of summertime heat stored by melt water and ice (if surface water re-freezes within ice crevasses at the end of season).

Accumulative impact moulins sit on ice sheet where subglacial ground inclination is inward, thus taking the melt water ever deeper into ice. Although some water re-freezes in crevasses to form those blue bands (occasionally seen in the ice bergs), the thermal inertia is absorbed by the surrounding ice matrix which warms.

Each subsequent summer see the energy required for melting decreased and in many cases there are growing liquid water pockets at the base of the ice sheet. At the end of this process, after just a decade of seriously warm post-sea ice summers, the ice is so honeycombed and soft that it cannot withstand overlying layers. The harder ice sheet surface caves in while the highly pressured slushy ice and water come out. This then triggers a rapid sea level jump, Heindrich (H-1) ice debris event and the Last Dryas.

Fourthly, the large supply of water triggers three rapid erosion forces. Those of cavitation, plucking and kolking and where the ice sheet edge meets ocean, the turbidic mud flows and rock falls like in Melville Bay. This region then rapidly subsides in a Storegga-slide style event pushed by the large ice islands launched to sea and the high pressure water jets that cause the three rapid erosion forces.

Besides ice free Arctic Ocean, the methane infested Arctic air will trap sun's energy far more effectively that it is still doing today. None of these things should surprise us.

wayne

Peter, "let us know how you are observing this underside melt, and where you're based? This melt doesn't seem to be visible to any of the sonar buoys across the Arctic."

The ice was not thinning and should not until the melt period is greater than 12 hours, so until yesterday there was a very slight net accretion worth about 1 or 2 hours a day. . Does your instrument used distinguish between "soft" ice and solid ice? That is how I know there is melting, drilling through the ice column there is soft ice in its bottom layer, this is an active zone of freezing and refreezing. So in fact your buoys seem to be correct. Remains to be seen if those near by show an actual thinning from about now, very slight for now.

Sorry I deleted your comment request on my blog site the link you gave was not working thought it was a hoax, me bad.

P-maker

Lewis,

Please don’t blame me, that the Royal Society missed this idea of increasing the surface reflectivity of ice using low cost, low tech and low risk means.

Here is what they did consider:

“Increasing the surface reflectivity of the planet, by
brightening human structures (eg by painting them
white), planting of crops with a high reflectivity, or
covering deserts with reflective material;”

c.f. http://royalsociety.org/uploadedFiles/Royal_Society_Content/policy/publications/2009/8693.pdf

With Arctic summer sea ice most likely gone within the next couple of years – and before the scenario of Veli Kallio starts to unfold - we may not have enough time to roll out a grand scheme like this (their Rec. 7.2)

“Relevant international scientific organisations
including the WMO, ICSU, Earth System Science
Partnership and UNFCCC/IPCC should coordinate
an international programme of research on
geoengineering methods with the aim of providing
an adequate evidence base with which to assess
their technical feasibility and risks, and reducing
uncertainties within ten years. This should include a
programme of observational work aimed at better
understanding possible responses of ecosystems,
atmospheric chemistry, clouds, and other
components of the Earth System. These observations
should be integrated into a programme of work to
develop and use Earth System models, Integrated
Assessment Models and state-of-the-art climate
models for the purposes of evaluating both SRM
and CDR methods.”

I know that emissions of soot from the EU have been higher in the past, but they rarely end up in Greenland.

I also know how big Greenland is and how rapidly we are losing albedo these years.

My proposal was merely an attempt to increase the resilience of the ice sheet, to gain some time.

Concerning your last question, I would say that when the number of storm surge victims start to outnumber the soldiers required to do the job, then we should start the field trial, to see if it works.

Neven

Lewis, I had planned to write about the ice microbes September last year when there were some news articles referring to the Japanese research, but unfortunately never got round to it.

Peter Ellis

Wayne: Thanks for clarifying that you weren't talking about net melting - that makes more sense now. I have no idea how well the buoys detect the active thaw/refreeze zone at the base of the ice.

P-maker: You're a loony. Buckets and spades? Even leaving aside the sheer implausibility of the scale of it (work out how much you can reasonably expect a man to shovel in a day, what area that equates to, and how many men you'd need to cover the ablation zone), it's a totally wrong-headed endeavour.

What will you do with the snow you scoop up? You can't just move it to a different part of Greenland, you know. That wouldn't achieve anything. You'd have to take it somewhere else, God knows how many gazillion tons of it. And then refrigerate it forever, using God knows how much energy to do so, because if you just let it melt, that itself constitutes a significant mass loss off the sheet. And what of the heat generated by the men on the ice sheet, and the machines required to cart the snow away?

"Just sweep up the dirty snow" my sweet aunt Fanny. Honestly, I'd expect more sense from any seven year old.

wayne

Peter, thanks also for the buoy data, which I can't look for now.
As an experiment I will say if the ice is thinning substantially and let your capable probes confirm it. Mean time I am working on a sea ice phase latency period, whereas there should be a time period, like melting ice or boiling water, when the horizon seems to be fixed before it changes phase, its another way of proving melting or freezing. http://eh2r.blogspot.ca/

Glacierchange.wordpress.com

Cryoconite only develops in glacier ice in the ablation zone, thus the accumulation zone and even the zone of firn will not develop these. This is largely because water drains through permeable snow and firn. Cryoconite requires long term water pooling in the small holes. In terms of expansion. This is a big region, and past observations of distribution are lacking, so it will be tough to observe. Though the albedo measurements of Box certainly suggest this could be occurring.

P-maker

@ Peter E

Having spent about one year altogether mainly in the ablation zone in Greenland makes you feel lonely from time to time, but that doesn’t make you a lunatic.

Observations of cryoconite holes has a clear observer bias, since these holes are mainly developed during sunny weather, when helicopters can fly and when it is fairly safe to operate on the ice.

What you observe, when it starts to rain, is that the ice surface is rapidly eroded, to the base of the cryoconite holes, so after a few days of rain on the ice, you will end up with a fresh and fairly even ice surface. Material from the bottom of the holes will follow the rivulets and will be redistributed into new patterns. After a few days of sunshine, new cryoconite holes will again develop.

Since rain on the ice is now a more and more frequent phenomenon – due to the vanishing sea ice and advection of warm and moist air masses from the south - we should expect to see more days without cryoconite holes. This will make it easier for the soldiers to collect the dirt. I did not mention snow at all in my posts, so please spare me the details of that exercise.

In case cryoconite holes remains a problem, I am sure that some ingenious young fellow will invent a solar powered vacuum cleaner to do the job.

PS Thanks for reminding me to bring buckets!

wayne

2007 great melt comes to mind today when apparently greater clearer
or cloudless skies spurred a record thawing. Some here have commented that 2007 was not so cloud free over the Arctic ocean . Last night at 75 N 95 W was clear, this prompted the ice to start a later underside melt by about 50 minutes. Later than when compared to a partially broken sky of may 10. The optical method of studying sea ice phase changes
seems to indicate a greater melting may be from a combination of clouds and strong sun light, will be more certain after several days of comparison, todays sequence was darkened to enhance the 1 hour phase change. http://eh2r.blogspot.ca/

Syddbridges

Neven, I think you are looking at Greenland melt the wrong way round. My Faux News brain tells me that there's no need to worry as they have every eventuality covered.
Anything under 573 Gtons, a massive recovery, which shows the utmost fraudulence of the alarmists, utterly crushing their case for ever.
573 Gtons. We told you the problem wasn't real. Recovery is happening fast.
574 Gtons. The position is totally stable. Nothing to see, move on.
575-650 Gtons. Statistically insignificant change caused by natural variation. Nothing to see, move on.
651-1500 Gtons. Who believes scientists, GPS, or tide gauges anyway? Nothing to see, move on.
1500-15000 Gtons. Who's worried about the odd centimeter or two of SLR? It's been happening for millennia.
15001-100000 Gtons. The number of ports that can handle deeper draught ships is a great benefit to commerce, especially with the newly opened up transpolar routes. What's wrong with that?
Entire GIS melts, killing or dispossessing 1.5 billion people. We told you that God was angry with the gays. Now he has drowned all these coastal Sodoms and Gomorrahs. We warned you that this would happen, but you didn't listen.

crandles

Foot soldiers? Buckets and spades?

We need to boost our economies with the production of laminated tin foil or something similar. Install with South facing slats so most snow falls through it but sunlight gets reflected ....

Also apply to roof space to reflect back to space (or towards nearby solar panels).

In fact why start with Greenland, start with dark areas eg above black tarmac roads ...

;)

Villabolo

Since we're on a roll here with Geo-engineering fantasies let me mention that science fiction writer Jerry Pournelle, in his book Oath of Fealty, came up with the idea of towing icebergs to supply household water to cities.

Won't do a damn for global warming but at least the faucets won't dry up.

;-)

Lewis Cleverdon

Neven - thanks for your response. I guessed that other issues might have pushed that of the cryoconites off the writing to-do list. The reason I'd urge a fresh focus on them is that the propensity to snow droughts under the rising occurrence of the Greenland high seems to me pretty much ideal for the acceleration of their expansion across the GIS.

If it is correct that the entrained and windborne dust have no significant darkening effect, as the clean white ice under emptied melt-lakes attests, then it is the microbial component of cryoconites that are capable of imposing very significant albedo loss to coincide with the peak of the melt season.

Given that the melt area since '79 has on average extended right across the GIS as far north as 67 degrees (NSIDC), and that this releases water through the permeable surface to form a fairly impermeable ice layer at the level that it freezes, the cryoconites' need to be able to form mini-pools is increasingly being met across potentially huge areas of what has been the accumulation zone as the accumulation declines.

In effect the ablation zone is gaining elevation, which is critical to the rate at which the ice-sheet's internal decay advances. To my mind it is not simply the area of additional melt lakes forming over newly impermeable ice that is troubling, but their location. For example, along the west coast for each five metres of extra altitude melt-lakes form at, there is around 1,000 kms2 of extra area whose moulins deliver melt water within the bedrock watershed to increase the retained water under the ice cap.

We already have around 60,000 kms2 in the SW and 20,000 kms2 in the SE whose melt-lake moulins are within the watershed and are feeding that reservoir (as can be seen by overlaying the watershed and maximum melt-lake altitude lines on a topographical map). Moreover that water is not heading for Jacobshaven but for the lowest point it can find, specifically the 300km-wide depression at about 68 degrees North. Only when the water-table in the arterial melt-water system and in any caverns it carves out exceeds the level of the bedrock watershed inland of Jacobshaven does it start to overflow to the sea. And at the end of the melt season and the end of that outflow it then has all winter to transfer its heat into the base of the ice sheet.

From this perspective the potential of snow droughts to assist the cryoconite microbial ecology's expansion not only along the coasts but also up and across higher elevations looks like a highly significant factor in the coming GIS melt rate, and in the advance of the date where the ice-sheet base is decayed to the point of starting to collapse into its underlying water reservoir.

All of which of course demands the caveat of:
"if we failed to apply effective geo-engineering to cool the arctic while we still have the geopolitical stability to agree to do so."

Regards,

Lewis

VaughnA

Veli Kallio,
Sounds at least plausible...do you have a timetable for these events to occur? How much ice would have to melt and how far from the edge of the ice sheet would this have to happen before we see these events?

R. Gates

Veli Kallio,

Your post was quite interesting. I'd like to hear more about this "Last Dryas" event specifically. Obviously a northern Atlantic choked with sea ice would do interesting things to the AMOC. Do you really see this happening? And if so, how intense, how long, and over what regions do you see a Dryas like cooling lasting?

R. Gates

Veli Kallio,

Your post was quite interesting. I'd like to hear more about this "Last Dryas" event specifically. Obviously a northern Atlantic choked with sea ice would do interesting things to the AMOC. Do you really see this happening? And if so, how intense, how long, and over what regions do you see a Dryas like cooling lasting?

VaughnA

Veli Kallio and R. Gates, I am visualizing what a localized cooling would do so far south with all that extra energy in the atmosphere from more distant regions.

Boa05att

A new paleoclimate study in Science suggests that climate sensitivity in the arctic is even higher the previously thought, and that the GIS was likely to have frequently been in an almost ice free state.

' “One of our major findings is that the Arctic was very warm in the Pliocene [~ 5.3 to 2.6 million years ago] when others have suggestedatmospheric CO2 was very much like levels we see today. This could tell us where we are going in the near future. In other words, the Earth system response to small changes in carbon dioxide is bigger than suggested by earlier models,” the authors state. '

Press release:
http://www.umass.edu/newsoffice/ice-free-arctic-may-be-our-future-say-umass-amherst-international-researchers

See this excellent talk for a presentation of the results:
http://www.youtube.com/watch?v=YxbOSB7zDgY&feature=player_embedded

bluesky

Thanks Boa05att for the great video on el'gygytgyn

another good video on lake el'gygytgyn, the most interesting is after 20 minutes or so:
http://www.youtube.com/watch?v=MDWUzWAtiyQ

bluesky

Boa05att, another interesting comment from the paper you mentionned:
"Finally, the new Lake E paleoclimate reconstructions and climate modeling are consistent with estimates made by other research groups that support the idea that Earth's climate sensitivity to CO2 may well be higher than suggested by the 2007 report of the Intergovernmental Panel on Climate Change." Will amazing researches on lake El'Gygytgyn sediments be taken into account in IPCC 2014??

wayne

Got some big discoveries if they hold true especially after further observations. One, clear skies favor longer freezing periods when the sun is lower in elevation as compared with partially cloudy days. And 2, a strong proof of underside sea ice melting can be visualized by the horizon remaining at the same local noon levels despite higher and lower sun elevations, a natural display of the melting phase. http://eh2r.blogspot.ca/

Hans Gunnstaddar

http://nsidc.org/greenland-today/

I’ve been checking the above link daily, which as of today is the first time it’s shown melt in Greenland beyond just a couple of orange dots. Looks like the melt season is well underway.

wayne

Clouds returned on May 15, the sea ice period appeared to freeze way less from their presence.
Again confirming that clear sunny Arctic skies do not necessarily mean a dramatic decrease in thickness. At least during spring time.

wayne

Neven, a serious look back at 2007 and 2012 great melts with respect to clouds should be done. My latest observations confirm again the most lethal damage to sea ice is not from direct sun light on clear days, but rather with sunlight piercing through the clouds on a partially cloudy day, especially night. I forgot the commenter's name who said 2007 wasn't that cloud free, this person was likely right. But a revisit of these 2 summer melt downs may sharpen prediction skills. Latest observations reveal a sharp brutal freezing after the midnight sun lowers diurnally , which means from April- most of May, Late July and August till mid September- clear days may offer a reprieve from a super melt down. http://eh2r.blogspot.ca/

Neven

Neven, a serious look back at 2007 and 2012 great melts with respect to clouds should be done.

I agree that would be great, but to be honest, I wouldn't know where to start.

Artful Dodger

Hi Wayne, Neven: BTDT ;^)

Kay, Jennifer E., et al. "The contribution of cloud and radiation anomalies to the 2007 Arctic sea ice extent minimum." Geophysical Research Letters 35.8 (2008).

Get the PDF from UCAR.edu

Al Rodger

An interesting Greenland-esque paper within the Skeptical Science weekly listings.
J.L. Chen, C.R. Wilson, J.C. Ries, B.D. Tapley Rapid ice melting drives Earth’s pole to the east.
The article linked by SkSc is here & the full paper here.
I would warn folk not to be carried away by the size of the arrow in the paper's figure 2b. The units 'mas' are milliarc-seconds which are by my reckoning about 30mm long.

wayne

Thanks Artful, that was a good paper, but they missed the months preceding June and following August. May and September also plays a role in any melt. The 60 % cloudiness also seems right, it wasn't that clear, even in June July at near 50%. The conclusion of .3 meter melt due to decrease cloud cover applies well for June until mid July. Because we have now the same amount of sun cover as mid July, current observations show that late clear nights are not so conducive to melting. But rather a cloud diurnal effect may be more important, such as clear during the day, and cloudy at night, if there was a way to see if the cloud radar graphs can be broken in 2. One for Local Apparent Noon and other for Local Apparent Midnight cloud cover may be more revealing. This can be usually so, a natural cycle, when the sun lowers to midnight, fog and other low clouds usually take place. A similar cloud analysis for 2012 melt season would be useful.

P-maker

wayne,

You are absolutely right. It is the most efficient way to melt ice, and it happens from time to time in the Arctic, particularly during the first half of the melting season.

Cheers

P

wayne

P-maker

We are now equipped with the best knowledge to date, there is a short time period when direct sun has a huge impact, for the 70-80 N area its likely most of June till mid july. The rest of the season is dependent on the cloud sunlight mix. We can do a series of satellite pictures one at local apparent noon, the other at local apparent midnight. If it gets cloudy regularly only at LAM outside of the short sun sensitive period, it will be the greatest melt by a large margin.

wayne

The northpole Cam 2 shows a significant drop of the horizon, as expected, the difference with april 16 seems quite large, more so than I expected. For the time being what counts is that it indeed lowered. http://eh2r.blogspot.ca/2013/04/north-pole-horizon-drop-confirmed.html

wayne

The only way the horizon would drop near the Pole would be for the camera to rise by several meters (like 10 giving a dip) or for the sea ice to melt in the underside and or for the sea ice physical properties to change, ie more rotten bottom side ice. I finally looked at Peter Elis Mass Buoy (a sonar result) the http://imb.crrel.usace.army.mil/irid_data/2013B_thick.png

the accretion has stopped, there was a bottom melt although slight , it is pretty much like I am thinking, especially near the North Pole where the sun has a very weak variation in altitude which gives a lesser freezing diurnal variation.

Further to the South, this is becoming certain, direct sun 23 degrees high in the sky or higher melts underside ice, but not
completely it refreezes as the midnight sun goes lower. There is a day time melt and night time freeze cycle. Only to be broken by low clouds or a higher night time sun which will never achieve 23 degrees at 75 N, but will do at the Pole.

There is always a daily midnight sun diurnal effect South of the Pole to 65 North which favors a reprieve from the melting unless the surface temperatures are warm. This suggests that there can't be any massive melt in strictly prolonged clear air as long as there is sea ice present. In other words without low clouds, massive sea ice loss is unlikely. http://eh2r.blogspot.ca/

Verify your Comment

Previewing your Comment

This is only a preview. Your comment has not yet been posted.

Working...
Your comment could not be posted. Error type:
Your comment has been posted. Post another comment

The letters and numbers you entered did not match the image. Please try again.

As a final step before posting your comment, enter the letters and numbers you see in the image below. This prevents automated programs from posting comments.

Having trouble reading this image? View an alternate.

Working...

Post a comment