« PIOMAS March 2017 | Main | Praying polar bear »


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

Tor Bejnar

My recollection is that 'constant' winds clearing the ice out of parts of the Beaufort Sea (sending it to the Rangel Island area) was a significant part of last year's (green line) April-May low extent. Maybe this year there will be an Atlantic sector 'clearance sale'.

Jim Hunt

Thanks for the mention Neven, and I'm quietly confident that we're all now safe from being forced to eat crow filled humble pie!

However I fear I have to report that the purveyors of cherry soaked porky pies are still hard at work in the darker corners of the cryodenialosphere. More on the assorted Arctic specific instances in due course, but this one is hot off the virtual presses in the basement of Great White Con Ivory Towers this very morning:


Last night the Mail Online web site... published an excuse for a “correction” to the egregious inaccuracy published on February 19th 2017 as part of David Rose’s self christened “Climategate 2” campaign in the Mail on Sunday.


Interesting that Bering and Okhotsk were the biggest contributors to the new record - I wouldn't have guessed that after the series of Atlantic-side lows and heat advection this winter.
I expect a flattish graph for the next week or two, with erratic gains in Bering, Baffin and maybe Greenland followed by a partial refreeze in Kara. That would bring this year and last close together - then maybe neck-and-neck for a while.


-Fish aka George here-

The drop in the Kara sea, which doesn't look like much yet, is the big deal in the start of this melt season. A number of maps of snow and sea ice show the snow retreating in NW Europe way ahead of schedule. The heat will continue this melt pattern and the bare ground will amplify the heating. Northern Eurasia is set to have a hot spring and the ice on the Arctic shores of Eurasia is set for a very early melt out.

We're on track for record low ice area, extent and volume in September and a brutally hot summer in northern Russia.

Rascal Dog

Based on PIOMAS volumes, an average change in volume from day 59 to the minimum volume would get the Arctic ice volume to as low of volume as in 2012. A very hot spring/summer (somewhat more than 2 standard deviations) would get to a volume consistent with a "ice free" Arctic Ocean. "Ice free" means some ice remains near Canadian islands and Greenland.


I've never seen this possibility before.


Brilliant Jim,

In all ways, don't forget to paste and copy this retraction correction every time Mr Rose decides to go on a fake science rampage . For now, the Mail on Sunday, not thoughtful or cunning, think they can do this again, lie and correct later in fine almost hidden print, they will of course, but we can put it back again and again in front of any fib they come up with. Congrats!


The curve for the average extent for the 2010's (2010-2017) now runs near or below the -2 standard deviations line on Pettit's graph for most of the year.


Sorry about that last post; please feel free to delete it.


Interesting that Bering and Okhotsk were the biggest contributors to the new record - I wouldn't have guessed that after the series of Atlantic-side lows and heat advection this winter.

Indeed, iceman. I concluded it when looking at the regional graphs, particularly Wipneus' Uni Hamburg AMSR2 sea ice area overview graph.

Of course, those lows also caused a kind of Beaufort Gyre-type export on the Atlantic side of the Arctic.

I expect a flattish graph for the next week or two, with erratic gains in Bering, Baffin and maybe Greenland followed by a partial refreeze in Kara.

I don't know about Bering and Baffin, but you may be right about Kara. The open water 'refroze' again in 2011 and 2012. It depends on the winds also.

Rob Dekker

Rascal, thank you for your assessment of the PIOMAS volume data, as it reflects on the upcoming melting season.
In short : Yours are intimidating numbers.
A bit scary I may add.

Jim Hunt

Neven - FYI, my combined "Pacific periphery" area chart confirms the recent sudden drops on that side of the Arctic:


Jim Hunt

Wayne - Thank you for your kind words!

The next step is to try and "persuade" the Fail on Sunday to "correct" some of the other porky pies in that article. By way of example:


Then of course there's the two preceeding episodes of their long running fantasy fiction soap opera.


That's a great chart that shows the main cause of the lowest maximum on record, Jim. Thanks a lot.



I second what Neven wrote, we may be outnumbered by the fringe media maniacs, but we beat them every time with facts. Let's hope the drive to get real facts and science will always win the interest of most people as well.

Jim Hunt

To be frank Wayne, "hope" is not in general a winning strategy. I think we also need to get our ClimateBall™ "marketing" sh1t together.

Compare and contrast these slideshows of the "Scientific" versus the "Skeptical" approach:


You will note that the Daily Fail features prominently in one of them. Then read this:


Are you aware that in its current war on evidence driven policy making the House Committee on Science, Space & Technology quotes the likes of Delingpole, Rose and Curry?

Susan Anderson

From a highly amateur nontechnical point of view, I look at something like this daily. Note the greens are mostly above freezing point. Svalbard has had many days above freezing throughout much of the winter. Those arrows of warmth from the south come and go but I doubt it is anything like normal for it to be above freezing regularly in winter.


Many thanks for the namecheck Neven - much appreciated. I thought that after lurking in the shadows since the early days of the forum I ought to contribute something!

Incidentally, I've further tortured my graph into an Arctic chart / album cover mashup (for any music fans out there) - located at



Totally agree Jim,

I would add that we often miss the boat, or end up drowning in words not understood by the audience we want to reach.

I can put it this way: "Arctic sea ice is a similar to a graph, it is a display of the current state of heat of the planet, Earth warms, there is more water instead of sea ice, Earth cools, the North becomes more white with expanded snow covered ice. Within natural variations prior to industrial revolution, sea ice was at least 3 meters thick from Canada to Russia, Polar animals spread out and populated the entire Arctic with likewise species because of this. High Arctic human habitation ruins going back 5000 years were never found near sparse animal populations caused by permanent sea ice presence, a wide open Arctic Ocean has never existed in human experience. Bowhead whales from the Atlantic are genetically distinct from the Pacific, if there was wide open water in the Arctic Ocean basin at times there would be a vastly different archeological and biological track ."

I think we can come up with a generic irrefutable explanation, is a matter of making it known. While the fake skeptics prey on ignorance, we can correct their uneducated not researched fictitious concepts with one click.

Rob Dekker

Jim, thank you so much for reporting on the Ding et al 2017 paper.
I just read it in detail and would like to report my findings here.

The essence of the conclusion (attribution to AGW) of the paper lies in this section :

to estimate the anthropogenic contribution to the observed warming and sea-ice reduction in t he Arctic, two additional experiments are conducted. Exp-7 and 8 are equivalent to Exp-2 but we remove t he effects of global warming on the high-latitude winds, which are used to constrain the model in Exp-2 (Supplementary Fig . 8). These results show the same strong geopotential height increases as in Exp-2, with approximately 70% of Arctic low-level warming and sea-ice extent change (north of 70◦N) relative to Exp-2. Hence, these experiments suggest that ∼30% of the anomalous thermodynamic sea-ice extent reduction is attributable to anthropogenic influences on the Arctic circulation. Applying this estimate to the overall circulation-driven sea-ice trend established in Exp-6 (60%), we estimate that about ∼42% (70% × 60%) of the sea-ice decline observed since 1979 in September is due to internal variability.

Now, both these fractions (70% and 60%) are questionable.

First of all, the 60% number refers to the correlation between sea-ice trend and atmospheric circulation over the Arctic.
However, that does NOT say how much atmospheric circulation over the Arctic is influenced by temperature.
Since higher temperature means expanding air mass, geopotential height will always increase with increasing temperature, which their own findings in figure 1e of the paper clearly shows (best correlation of geopotential height at 200 mb is with temperature).
So that 60% influence of atmospheric circulation can very well be simply caused by atmospheric temperature increase, which can easily be AGW in origin. After all, Z200 is high up in the atmosphere, which means that even during summer it is not much influenced by melting sea ice below.

And the 70% (natural variability) refers only to the influence of “high-altitude winds”.
Here, again, high altitude winds (such as the jet stream) are caused by geopotential height, which is again caused by temperature changes over the Arctic. If the Arctic warms more than the rest of the planet (due to albedo feedback or increase in moisture or any other reason), the geopotential height over the Arctic will increase more than the rest of the planet, and thus the high altitude winds will be less “cyclonic” than otherwise. That means this “70% (natural variability of the atmospheric circulation over the Arctic)” may very well be completely caused by temperature increase.

So both numbers are highly dependent on temperature increase, and since the paper does NOT investigate the correlation of these variables to temperature increase, even though its own analysis establishes that correlation very clearly (fig. 1) its conclusions are not sustained by the evidence they collected.

As William Connolly wrote (thank you Jim for reporting on that :

they then convince themselves that most of the circulation changes that matter to the ice are not GW forced, and so must be natural variability; and hence the conclusion.

Rob Dekker

For all the words written in this paper (Ding et al 2017) and all the correlations and experiments they performed it is surprising that they did not even investigate the most obvious test of AGW attribution of them all : A correlation between summer temperature and sea ice extent.



The above is dedicated to NOAA , ESA and NASA type guys and of course ladies who want proper top of sea ice temperatures. There is the first sea ice horizon refraction rule:

Ts >= Ttsi

The top of sea ice (snow) is always colder or equal to surface air. This was first observed optically, then I tried to prove it by buoy data in darkness somewhat successfully, and now with a high precision thermistor unit. It is so.

And Jim

Got an ancient UK inspired idea, if top of buoys thermistors had a snow HENGE , yes the henge circle, say quite distant away, so snow doesn't fill it all, some top thermistors would be in a shade for a greater period of time and measure correct top temperatures. It is either that, or a robotic arm, making a shade by pilling up a snow drift around the thermistor column.

Rob Dekker

I dropped the same comment on William Connolley's site
since Eric Steig (a coauthor whom I respect very much) commented there. Let's see what the response is.


It is rather interesting how it is going, in comparison, isn't it..

Given ice dynamics between the two years and the impact that they play on the ice, almost an exact match so far. Except for the fact that 2017 is much, much, lower.

I wonder if it will continue??


Should have put,

Larger image

Jim Hunt

Wayne - At the risk of drifting even further off topic, here is a very recent article on the very latest research into the troubled subject of science communication:

"The Problem With Facts"

These two forms of evidence paint a picture — a flattering one indeed — of individuals of high science curiosity. In this view, individuals who have an appetite to be surprised by scientific information — who find it pleasurable to discover that the world does not work as they expected — do not turn this feature of their personality off when they engage political information but rather indulge it in that setting as well, exposing themselves more readily to information that defies their expectations about facts on contested issues. The result is that these citizens, unlike their less curious counterparts, react more open mindedly and respond more uniformly across the political spectrum to the best available evidence.


My response Jim would be inspired by Monty Python greatest joke ever written, so funny it kills anyone who reads it. Therefore a less lethal generic anti natural cycles page, so devastatingly brilliant any one reading it would evolve to be an entry level sea ice scientist. We can do it, we have so much talent here, we can write a novel about a snow flake. This is the conversion factor needed from accepting a dumb erroneous seductive simplification to the complex brilliance of sea ice itself, mere words convert people to accept stupidity, many Shakespeare's in the past changed the world, made it smarter.


Occam razor applied, these nice numerical experiments fall in the wrong side.
Too complicated, Feynman said a satisfying theory is a simple theory.
Higher temperature->ice melts

Jim Hunt

Wayne - My very good friend Alice F. has somehow managed to dig up some more dirt on David Rose:


Do you suppose his toes are starting to feel a trifle toasty yet?



I think Murphy's Law will apply and he will get a promotion to Faux News or some other dumbing down brain washing outlet. Is very appropriate to highlight and remind all of Mail on Sunday D.R. retractions at every new article he dishes out.

Philip Cohen

Peter Principle.


Hi Philip,

In this case, it would be a catastrophe if this principle pans out. :)


I used a high precision thermistor, this time over Barrow Strait sea ice,
the temperature of top of snow on sea ice reacted identically than with snow layer on land, except sea ice area had warmer surface surface temperatures. Of course if we extrapolate this for the entire Arctic Ocean, Arctic Islands and lands have a colder potential to spring up Anticyclones than over frozen top of ocean much warmed by thinner sea ice. NOAA physical sciences division
model is not so bad, essentially confirms the first rule of sea ice horizon refraction, but has trouble with quite some distance from shore lines, as if there was a calculation gracefully adjusting the temperature differences, this is not so.

Another of my main corpus of discoveries requiring a second deeper look by the big leagues researchers. If a model presents the temperature of top of sea ice warmer than surface air this may not be correct, unless there is water on top.

Al Rodger

Rob Dekker,
Ding et al (2017) does address a worry that imposes itself on polar climatology. I think it presents a useful result but that result is presented in such a way that it can be used to suggest that natural variability is responsible for perhaps half of the loss of Arctic SIE recorded over the last four decades - a suggestion which is patently false. Importantly, it is not the absolute loss of SIE in 'millions sq km' which Ding et al address. It is the trend in SIE decline in 'millions sq km/decade'.Sadly the paper does not assist very well in preventing its findings being misrepresented.
If you plot (as Rob Dekker suggests) temperature against Sept Arctic SIE, what do you see? For temperature, HadCRUT4 global is probably the best choice. It doesn't have a lot of Arctic weighting so we are surely comparing AGW against SIE without picking up any natural Arctic temperature wobbles. The resulting plot shows a strong linear relationship except for the period 2007-12. It is that wobble (which is now over) that impacts the calculation of trend in SIE decline. The trend in SIE if the wobble years are ignored (and using 1979-2014 as per Ding et al) is something like 0.6M sq km/decade. If the wobble-years are reinstated, the trend increases to 0.9M sq km/decade, yielding a 33% reduction due to the wobble which is a result not greatly different to Ding et al's 43%.
But importantly, that wobble is now over and as of 2016 there is no significant natural wobble impacting the levels of summer SIE.


Over on the Arctic Sea Ice Forum I have posted an animation of the current sea ice retreat in the Kara Sea (south of Novaya Zemlya), as compared to the retreats in 2011 and 2012. The big question is whether the ice will get shoved back again, or the water re-freezes again (like happened in 2011 and 2012), or whether it will stay open this time. If it does, that will be unprecedented.

Rob Dekker

Al Rogers

I think it presents a useful result but that result is presented in such a way that it can be used to suggest that natural variability is responsible for perhaps half of the loss of Arctic SIE recorded over the last four decades - a suggestion which is patently false.

You are right, but still it is a challenge to actually show where the paper goes wrong. I think I found the problem with Ding et al 2017 in this comment :

Rob Dekker

Needless to say that I think the conclusions from Ding et al 2017 are flawed.

The valid conclusion that I think we can draw from the Ding et al 2017 paper findings is this :

60% of Arctic sea ice reduction is caused by summer-time climate change, while 40% is caused by climate change over the remaining 9 months.

Which is a very interesting conclusion by itself.



I think we should work on a fake skeptic antidote page, come up with something so powerful we would make a big oil fat cat cry. So take it from here and "start to make it better" like the 1968 Beatles song sings:

"Arctic sea ice is a similar to a graph, it is a display of the current state of heat of the planet, Earth warms, there is more water instead of sea ice, Earth cools, the North becomes more white with expanded snow covered ice. Within natural variations prior to industrial revolution, sea ice was at least 3 meters thick from Canada to Russia, Polar animals spread out and populated the entire Arctic with likewise species because of this. High Arctic human habitation ruins going back 5000 years were never found near sparse animal populations caused by permanent sea ice presence, a wide open Arctic Ocean has never existed in human experience. Bowhead whales from the Atlantic are genetically distinct from the Pacific, if there was wide open water in the Arctic Ocean basin at times there would be a vastly different archeological and biological temporal trail. Despite high latitudes lower sun in the sky, there was always enough solar energy to melt the entire ice pack many times over at any summer throughout geological history, but the very nature of sea ice is to reflect solar radiation up to 90 % of it because of the lower sun angle and especially with snow cover. Clouds added on an extra layer of sun ray reflectivity up to 80% especially when it mattered. The very nature of sea ice creates clouds in the spring summer by increasing the surface relative humidity of air well above 70%, sun rays even help create an insulation ice crystal laced fog. In total winter darkness thick sea ice cover clouds are naturally reduced by the drying out of the Arctic atmosphere lifting its protective heat cover, increasing heat radiation loss to space always creating thicker sea ice for months, ensuring a main massive amount of sea ice to exist at summer end by mid September ..... "

A bit more points to add, rewrite it up like a poem and let the dumb ideas explode in the aether of nowhere.

Jim Hunt

Wayne - Perhaps we could package it into 140 character chunks and "Tweet" it to @POTUS?



Good idea Jim

But it wont work, because he only reads certain tweets of a select few grand illuminati's, Kane West, TMZ, Faux News, Hulk Hogan, Blimey Piers Morgan, Matt the bottom Dredger, not one scientist I am afraid. Daughter did not stand in the way of Pruitt nomination. Foget about it.



Global Sea Ice Graphics seem to be strangely attractive these days...


Particular care must be given for snow analysis, there seems to be a lot of it throughout the Arctic. If so expect a bit later massive melt drops, also I wonder if analysis of sea ice thickness is correct given current apparent much thicker snow layer.


There may be less sea ice than ESA projects. Depends on whether there is a remote sensing caveat with respect to snow cover, is it likely there is less sea ice thickness when the snow layer is thicker?

"We show theoretically
that relative ice thickness uncertainties between 20%
and 80% can be expected for typical freeboard and snow

"Antarctic sea-ice thickness estimations
are high and likely of the order of 50%. This is only a
ballpark number. Uncertainties vary in space and time and
depend on absolute total freeboard values, number of valid
ICESat measurements and snow depth."



I have here:


practical techniques as to where thinner thicker ice is, without AMSR2 or a dedicated for sea ice satellite, it is a complementary method adding another tool to your sea ice evaluation kit.

Jim Hunt

For the attention of the powers that be. The ASIF currently tells me:

"Table './arcticse2/smf_messages' is marked as crashed and last (automatic?) repair failed"


Wasn't there some sort of notification that this is a scheduled maintenance operation? Give it time.


The Arctic Sea Ice Forum is down:

Database Error
Please try again. If you come back to this error screen, report the error to an administrator.


I just got behind the computer, sorry. I have notified Fred, who hosts the ASIF on a server somewhere. I'm sure he'll fix things as soon as he can.

There had to be a first...

Jim Hunt

Fingers crossed here in Soggy South West England Neven!

Meanwhile, in the absence of the ASIF here is the news that I wished to report:

"Should Climate Scientists Boycott Congressional Hearings?"

According to retired Rear Admiral David Titley they should:

It seems David wasn't too impressed by the hearing he got from Senator Ted Cruz concerning "Data or Dogma"!

Jim Hunt

Fred seems to have done the trick!

Or maybe it was the crossed fingers?

Bill Fothergill

As noted in the preceding four comments, the ASIF server has temporarily turned up its toes.

I was going to post a comment about yet another milestone on the "Sea Ice Extent around Antarctica" thread
but, in its absence, I'll mention it here instead.

Every day since the 5th November 2016, Antarctic sea ice extent has been at record low levels. The NSIDC daily Antarctic sea ice extent value for March 27th came in at 3.304 million sq kms. This was a somewhat jaw-dropping 2.037 million sq kms lower than the equivalent figure from last year.

The cumulative effect of just over 20 weeks at record low levels has obviously been dragging down the rolling 365-day annual average extent figure. In fact, for the last 5 days, this average extent value has been dropping at over 5k sq kms each day.

The latest (as at 27th March) rolling 365-day average extent value has now dropped to 10.966 million sq kms. The previous record low average was 10.969 million sq kms (6th Aug 1979 - 4th Aug 1980).

To give a bit more perspective, decadal averages (calculated from the NSIDC monthly values) come out as...

1980-89 11.82 million sq kms
1990-99 12.03 million sq kms
2000-09 12.18 million sq kms
2010-16 12.46 million sq kms

Several weeks ago, on the relevant ASIF thread, I had been demonstrably cautious when I had suggested that the rolling 365-day figure would drop below 11 million sq kms by the end of March, and could likely surpass the previous record low sometime toward the end of April.

CAVEAT: Prior to the 20th Aug 1987, figures were produced on alternate days. Therefore, during that earlier record low period (1979-1980), the rolling 365-day figure actually comprised just 183 data points. The implicit assumption is, of course, that the "missing" days will, on average, tend to be halfway between the before/after dates. Some will be lower, some will be higher, but this should just about even out over the 182 "missing" days.

Bill Fothergill

Whilst I was typing the above, Jim Hunt has managed to post twice, and the ASIF is back in business.



Yes, it's back up. It was probably Fred who crossed his fingers the right way.

Speaking of milestones, this month the ASIF has broken the record of most page views in a month, and is currently at almost 1.7 million page views for March.

Bill Fothergill

@ Jim H:

Rear Admiral (ret'd) Titley: my hero - I wonder if he writes his own punch lines?

My favourite was when questioned about what impact rising sea level could have on defence capabilities.

"We tend to build our bases at sea level ... we’re not the Air Force, we can’t build our bases at 6,000 feet" Brilliant!

Jim Hunt

Bill - It seems the ex Admiral rather "liked" my alter ego's recent "tweet" of one of his punch lines:


"If you wait for 100% certainty on the battlefield you'll probably be dead"

Bill Fothergill

Some people regard debating with climate change "sceptics" as something of a contact sport; for those who do, you might enjoy a perusal of the comments section in this article by Jim Hunt...


Keep an eye open for comments by Michael Olsen, Timo Soren and Arno Arrak. It's funny how these people seem to clam up after their initial bluster.

Jim Hunt

Bill/Wayne - There was a great example of the "contact sport" of ClimateBall™ played yesterday at the behest of the United States’ House Committee on Science, Space and Technology:

"The House Science Climate Model Show Trial"

There's over 2 hours of riveting video for the cognoscenti to analyse. Michael Mann seemed to be working from "Snow White's" playbook at times, and devoted several paragraphs of his written testimony to criticising the David and Judy Show in no uncertain terms.

Lamar Smith didn't appear to be listening though. Lots of bluster but sadly no clamming up! He did however demote the Fail on Sunday to the substitute's bench, replacing them on the field with the Wall Street Journal.



It does not take much effort to ridicule proper science, it takes only a pulpit, media with audience. The fake skeptics best points are taken from repeated falsehoods, thus ignorance spreads like a plague. But this is nothing new, we humans have been digging out from superstition mud traps ever since drawing nature scenes in caves for the first time. From then, we progressed in steps always followed by dark ages, but now we can paint with electrons, something anti-science gangs eagerly do without appreciating the great enlightenment making this possible, while not realizing their base need for spreading some regressive stupid agenda which will do way more damage than fleas carrying pestis, how small minded and powerful some persons may be.

Jim Hunt

Wayne - In the latest "Shock News!" from the calving face the "fake skeptics" at the Fail on Sunday have been forced to "correct" their recent "correction" to the most recent cherry sauce soaked porky pie to fall off the end of their production line:

"Stale News? Mail on Sunday Corrects Yet Another David Rose “Porky Pie”"


Great job Jim

I would agree they regret being wrong if they retract all their misleading articles, it would take more than a few words. This is bait and switch again, excite the spread of moronism then insinuate a serious institution practice. Keeping afloat a semblance of journalism does not make for a good newspaper.

Are you getting any buoy thermistor data this season?


Also Jim

No big news, but I can say with a fairly high level degree of confidence that all mass Buoy top 4 or 5 thermistors had sun radiation artifacts. Spring time top thermistors at night or with lower sun were always colder than surface air, however this does not change much during the day unless surface air is greater than 0 C. A work around would be to evaluate the much more precise surface air data, when there is a stall in diurnal warming, this is likely latent heat of snow or sea ice effect, when the partial Short Wave radiation absorption warms top of snow and ice column. Understanding this process has huge implications,
one of which is melt ponds, if top of ice is always colder or same temperature as surface air, the only time when melt ponds can occur is when surface air is warmer than 0 C. Unlike what top thermistors buoy data might have suggested. There is another very top snow skin process at work as well.



I think the denial-peddlers are getting a bit desperate- and therefore more strident - as the younger half of the audience (at least) are slipping away from their grasp as they see what's happening outside the window. Unprecendented weather, not just in the Arctic is demolishing the false equivalence. More of the fossil-fueled comment BTL on sites like the guardian is along the lines of "It's too late to do anything?" - reminds me of the Simpson's classic fugu episode

Events like the 47C heatwave in Sydney while our local trumpoids juggled a lump of coal in parliament didn't go down well despite media urging.

The trogodolytes in power now are making a last stand for the vested interests. That doesn't make the situation rosy or anything given the pace with which AGW is unfolding


Hi Subgeometer

There is also the most important responses, individual actions, either buying an electric car or a bicycle ride to corner store instead of driving a Hummer. All these combined a million times have the largest over all influence in the long run. Hope exists despite the flat Earth people who will never give up Job's table on 4 pillars at the center of our candles are stars universe.


Any thicker snow over sea ice , as there appears to be over the central basin, Kara and Barents can give an illusion if not a false measurement of thicker sea ice. Although the melt would stall, because sea ice with a good snow cover has high albedo. However, snow sublimation is a 24 hour continuous process increasing water vapor which brings more fog, equally good to further a melt stall. Eventually vaporizing snow will leave a more bare sea ice surface , with much reduced albedo, the vaporized snow will flip its thermal effects from cooling to warming with a higher sun since water vapor is also a greenhouse gas, sudden rapid melt within those snow rich areas will surprise, as snow vanishes the revelation of a much thinner sea ice will make for bleak pictures. So I expect a slower or normal melt period for a while then a sudden dramatic high speed melt rate along with scary pictures of much fractured sea ice.

Snow illusions aside, linking sublimation with inversions may interest a few:


Hans Gunnstaddar


Time lapse of a glacier receding.

Jim Hunt

Wayne - In the latest news from the Beaufort Sea, the thickness of the sea ice underneath ice mass balance buoy 2017A has just crept over 1 meter:

Current Buoy Data (04/03/2017):

Pos: 72.90 N, 147.10 W
Air Temp: -25.88 C
Air Pres: 1021.52 mb
Snow depth : 9 cm
Ice thickness : 102 cm

Since Deployment (03/09/2017)

Snow surface accumulation: 9 cm
Ice bottom growth : 17 cm

I'll have to tweak my scripts a bit. At 04:00 on April 3rd when the red temperature profile was recorded the buoy reckoned "air temperature" was -20 Celsius.


Very interesting Jim

By the way, my latest research suggests taking buoy data at the lowest sun elevation possible, 04:00 to 08:00 UTC, so that top thermistors represent a closer temperature without being too much affected by sun irradiance effects.

This said 102 cm is very thin, despite 9 cm snow which is about more or less normal for a great accretion rate. Further East, snow thickness as much as 50 cm, has severely reduce sea ice thickness despite and in tandem with winter over all warmer temperatures, to about 130 cm near Barrow Strait shores. Without the greater snow cover , Beaufort sea ice 102 cm should largely be a result from a very warm winter.


I would suggest a slight add on for your Mass Buoy graphs Jim,

Would be very effective if the surface temperature should be represented
by a dot which would help detect top thermistors solar irradiance effects.

It is excessively difficult to make a proper temperature measurement of top of sea ice or snow when there is direct or indirect sunlight, even with reflected rays bounced downwards from clouds of thin fog affects thermistors. So it is only wise to study top thermistors when the sun is completely blocked ( by very opaque and wide cloud cover, or during the night time). A simple dot representing the surface reading would immediately give a reliability of readings. in essence "skin" temperature top of snow or ice should be colder or equal than surface, if not the data only represents a good study about photons warming thermistors.

Jim Hunt

Thanks for the suggestion Wayne. When I find the time to "tweak my scripts" I'll try and add an extra indication of air temperature.

I'm not sure that a disembodied "dot" will do the trick though. As more profiles are added things can get pretty cluttered. Maybe a dashed line to the air temp "dot"?


Dash line will do fine Jim

It will be a very strategic addition.



Jim's Buoy graph above reflects very well the fragile state of Beaufort sea ice as seen from space, 2016 had a stronger high pressure system, same date early April 2017 looks eerily similar minus the high pressure power.

The comments to this entry are closed.