ASI 2015 update 1: early start in Beaufort

During the melting season I'm writing (bi-)weekly updates on the current situation with regards to Arctic sea ice (ASI). Central to these updates are the daily Cryosphere Today sea ice area (SIA) and IJIS sea ice extent (SIE) numbers, which I compare to data from the 2005-2014 period (NSIDC has a good explanation of sea ice extent and area in their FAQ). I also look at other things like regional sea ice area, compactness, temperature and weather forecasts, anything of particular interest.

The animation on the right consists of NSIDC
sea ice concentration maps, one for each ASI update.

Check out the Arctic Sea Ice Graphs website (ASIG)
for daily updated graphs, maps, live webcam images and
the Arctic Sea Ice Forum (ASIF) for detailed discussions.

May 19th 2015

Here it is, the first Arctic Sea Ice update for the 2015 melting season, and boy, are we off to a flying start. But more about that later. First a quick overview of what's been happening the last few years.

After the 2007 melting season smashed the 2005 record minimum, it was equalled by the 2011 melting season and subsequently smashed itself by the 2012 melting season. Although the 2013 melting season didn't bode well at all, given the trend and the massive amount of first-year ice, the Arctic sea ice had its traditional post-record rebound after a cold and cloudy melting season.

This (volume) rebound had all but vanished at the start of the 2014 melting season, but again the melting season started out cold and cloudy, after which the sea ice hardly moved during the rest of the melting season. And so there was a similar rebound to the one following the 2013 melting season. However, this time the volume rebound was larger and lingered on through winter.

One would think the ice pack would be strengthened and more resistant to weather conditions at the start of the 2015 melting season. But this also depends on how the volume is distributed across the pack, and as we saw in the 2014/2015 Winter analysis I posted 10 days ago, all of the volume has piled up in the Central Arctic and the Canadian Archipelago, the sea ice's last safe haven. This basically means that as far as the periphery of the Arctic sea ice pack is concerned, there is no big difference with the other post-2007 years. This melting season could turn out to be another rebound, but it might just as well go as low as 2007, 2011 or even 2012. The only thing we know for certain, is that the Arctic won't see below 1 million km2 of sea ice come September, the definition of 'ice-free'.

The outcome is obviously determined by weather conditions, but this month and June are particularly important for what I like to call melting momentum. This momentum is determined by the amount of melt ponds that form on the ice pack during these two months, as they soak up more solar energy that would otherwise be reflected. 2012 had a relatively sunny and warm start of the melting season, after which a stable decrease couldn't be thrown off by weather that was less conducive to melting. And that's how the record was broken, compounded by the Great Arctic Cyclone in August. Conversely, 2013 and 2014 had cold and cloudy starts to the melting season, and this couldn't be made up later on during bouts of sunny weather.

And so melt ponds will be the main theme of this first phase of the melting season. In fact, I'm going to obsess over them in the next two months and report on them outside of the ASI updates. The amount of melting momentum decides whether the melting season has a chance of breaking records.

Off we go.

Sea ice area (SIA)

The people behind the Cryosphere Today website have been experiencing some trouble with their server and so data has been updated up to May 13th only:  The 2015 trend line is among the lowest on record. It will be interesting to see if it goes lowest once data is updated, as it is on the SIE chart.

Sea ice extent (SIE)

There was a delay in data delivery due to maintenance, but everything has been updated this morning:

This is pretty low, and it's probably going to stay that way for the time being.

Regional SIE and SIA

This year I'll be using the regional SIE and SIA graphs on the updated Arctic Sea Ice Graphs website, as provided by commenter and amateur Arctic expert Wipneus. But first, here's a map of the entire Arctic Wipneus has sent me yesterday to show where most of the ice has disappeared in the past two weeks (red = less ice than two weeks ago, blue = more ice than two weeks ago):

Just like last year the sea ice in the Bering and Okhotsk Seas melted out really quickly, which probably has a lot to do with that blob of hot water in the North-Pacific. These regions were also the main reason for the extremely early and record low maximum:

But as we can see on Wipneus' 2-week delta map for the entire Arctic, melt has started in the Kara and Beaufort Sea, and Hudson Bay:

Particularly the melt in the Beaufort Sea is very early, as can be seen on Concentration Maps for May 19th. But these sea ice concentration maps and regional graphs are not even telling the whole story. This LANCE-MODIS satellite image is:

As mentioned in the 2014/2015 Winter analysis there was a cracking event in April, and the ice possibly didn't have enough time for a substantial re-freeze, resulting in this broken mosaic of huge ice floes, interspersed with thin ice, and open water even.

But also clearly visible are the lack of snow on the Alaskan mainland that is in something of a heatwave, the early clearing of ice in the Amundsen Sea and a bluish hue on the fast ice and a part of the ice pack, which is a sign of - you guessed it - melt ponds. This is a very early start of the melting season in the Beaufort and Chukchi Seas, the places where a lot of the rebound multi-year ice has been transported this past winter to possibly form a barrier that protects the ice behind it:

Let's have a look at what the forecast has in store.

Weather conditions

Sea level pressure plays a crucial role in determining the position and percentage of melt ponds on the Arctic sea ice pack, as it gives an idea of where the open skies are and if there is a transport of warmer air from lower latitudes into the Arctic. Open skies due to high SLP mean lots of insolation.

This two-week animation of Danish Meteorological Institute SLP images shows what has been going on with regards to SLP: 

Weather systems aren't al that stable and follow each other in rapid succession, but a high pressure area is taking over the Beaufort towards the end of the animation. Like said, this means insolation, ehat being pulled in from the North Pacific and Alaska, and clockwise transport of (the cracked) sea ice towards the Siberian coast.

Here's the weather forecast for the coming 6 days according to the ECMWF model (click for a larger version):

It seems the highs are more or less sticking around over the Beaufort Sea. They're not particularly high (1015-1020 hPa isn't that high), but there will still be plenty of sunlight hitting that part of the ice pack. And so we turn to temperatures.

Surface air temperatures have been low across much of the Arctic sea ice, except for the Beaufort and Kara regions, but very low north of 80°as can be seen on the DMI 80N temperature graph:

The cold is also visible on the NOAA/ESRL 1-day anomaly map (the 7-day and 30-day maps can be found on the ASIG), although it has been slowly dissipating in the past couple of days:

Now this is where things get interesting, as the GFS temperature forecast is showing some massive changes. Below is an animation I made using actual temperature forecast maps provided by the excellent Climate Reanalyzer website (I'll be using temperature anomaly maps in future ASI updates, but these actual temperature maps nicely show the distinction between freezing blue and melting green):

This forecast is showing above freezing temperatures spreading over much of the ice pack. If you want to see how anomalous these temps are, you can check out the new Forecasts page on the ASIG. The forecast gets even warmer after that, but of course becomes less reliable the further out you go.

I can't interpret this in any other way than a heavy assault on the multi-year ice in the Beaufort and Chukchi Seas. This combination of above freezing temperatures and insolation should cause considerable melt ponding. At the same time it looks like melt onset is delayed somewhat on the Siberian side of the Arctic.

Of course, high temps across Alaska and NW Canada don't bode well when it comes to wildfires.

Sea surface temperature anomalies on the Atlantic side of the Arctic are already on the up side of things, slightly warmer compared to last year, with some orange showing up in the Beaufort Sea already, but these colours can fluctuate from day to day:

Despite the red blob in the North Pacific there's not much anomalously warm water to be seen near Bering Strait. It's possible that some of it is being transported below the surface waters through the Alaskan Coastal Current, but that's nothing more than speculation:

Conclusion

This melting season started out cold, like 2013 and 2014, but in the past week or so things have been changing, notably in the Beaufort and Chukchi Seas where a lot of multi-year ice has been transported to during winter. This ice is going to get it hard in the next week or so, which will probably mean that sea ice extent and area are going to keep tracking low, if not lowest, on their respective charts. But not only because of this, the ice in the Kara Sea and Hudson Bay is also looking fragile and in for a bout of (relatively) warm, sunny weather.

The big question now is how much melt ponds are going to form, as this is crucial for the melting momentum that can make or break a melting season's record potential. I'll be keeping as close a look on that as possible, as melt ponds are difficult to measure, and come back to it in the next ASI update at the start of June. Or as someone on the Arctic Sea Ice Forum called it Junction June.

Enjoy the Arctic sea ice, it's the only Arctic sea ice you've got.

Comments

[Neven]

As of tomorrow I'm going on a 10-day hiatus, also known as holiday. I'll be back on June 1st, fresh and fit for the rest of the melting season.

[navegante]

2015 vs 2014, time to test May-June "tipping point" theory for the melting season. Slow late start, a lot more resistance for melting throughout the season. Fast early start, a lot more difficult to stop the melting. Arctic amplification.

Eurasian side is late, but Beaufort-Chukchi side early start seemed to be crucial in 2007-2011-2012

[Neven]

According to the ADS sea ice monitor (hat-tip to, who else, Wipneus on the forum) melt ponds have started to form in the Beaufort and Chukchi Sea:

I don't know how reliable these maps are, but it makes sense.

[Jim Hunt]

Neven et al.

Do you believe the evidence of Landsat 8 plus your very own eyes? A large floe in the Beaufort Sea yesterday:

Click the image for the bigger picture.

[Bill Fothergill]

Thanks for the analysis Neven.

A quick observation as regards the University of Hamburg AMSR2 map you received from Wipneus: unless my eyes are playing up again, there appears to be a little blob of red lying to the north of Wrangel Island.

Didn't our unlamented former inmate "C" assure us that melting would fail to go beyond this point by September?

PS Enjoy the hiatus. I hope your diet will be more balanced than mine was.

@ Jim H - An interesting set of photos you have posted there, old chap. Does that look like some potential fracture lines already developing across the Nares?
Cheers BIll F

[Jim Hunt]

If you're still around Bill, do you fancy a Pint of Science in Exeter this evening? Ben Bradshaw and then Andy Williamson have stood me up and hence I have a spare ticket and a pint on offer! More info at:

http://pintofscience.co.uk/event/unzipping-your-genes/

An initial report on last night's event can be seen here :)

https://twitter.com/jim_hunt/status/600600280619679744

[Bill Fothergill]

Jim,

No can do, I'm afraid - this evening has already been mapped out by she who must be obeyed.

Great shame as I would have loved to attend - especially as I know the assistant manager in the Rusty Bike.

Catch you later

[Jim Hunt]

OK - Thanks Bill. Another time it will have to be :(

Will I get free beer if I mention your name?

[wayne]

Neven , I would have defined the cooling, but otherwise a very good synopsis.

My yearly projection of a month ago is on track,

http://eh2r.blogspot.ca/2015/04/annual-springsummer-projection-by.html

and I don't see anything breaking the momentum already in place.

Every season has different features, this one had a cold Arctic North American start driven all winter by a pan continental heat engine, in its wake is drier air because it snowed less and the Pacific is unusually warm causing a greater temperature dew point spread.

There is more potential insolation in polar regions summers compared to anywhere else ascalculated by Tamino:

https://tamino.wordpress.com/2012/10/01/sea-ice-insolation/

With less clouds there is automatically warmer temperatures and a greater melt.

[Chris Reynolds]

Good post Neven,

Fingers crossed for clear open skies and lots of melt ponds. Enjoy your holiday.

[D_C_S]

I'm hoping for a slow melt season.

[jdallen_wa]

I'm with you, D_C_S, but I'm pragmatic, and excited like everyone else seeing our predictions and hunches (however dire) borne out.

Would that it were not so.

I also say, if it is going to melt, let it do so in a way that is unambiguous in its proof of how much trouble we are in, so as to finally knock sense into the brains of those who continue to drag their feet.

[Paddy]

I won't be hoping for unambiguous proof myself, jdallen. Particularly given how many people report their beliefs actually being strengthened by contradictory evidence.

Also, ice area and extent have so much noise and so many disparate measures as indicators that people can easily interpret it selectively and seize on apparently contradictory "evidence"; the latest one that sceptics have been wheeling out in debate is that global sea ice area has been equal to the 1979-2008 average for the past two years (http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg).

Never mind that they liked to completely ignore it for the previous two years, when it was well below said average, or that if you drew a regression line through the whole history, it would go down :S

[Colorado Bob]

Richard Alley at INSTAAR, April 2015.

Published on Apr 13, 2015.

Glaciologist Richard Alley shares recent research on the state of the West Antarctic Ice Sheet, climate change, and what it means for people living near the coasts in "Crumbling Ice Cliffs? Not-So-Good News for Low Coasts." INSTAAR Monday Seminar, 6 April 2015, University of Colorado Boulder.

https://www.youtube.com/watch?v=yCunWFmvUfo

[Bill Fothergill]

@ Paddy

"the latest one that sceptics have been wheeling out in debate is that global sea ice area has been equal to the 1979-2008 average for the past two years"

From the Cryosphere Today dataset at UIUC, the average Arctic Sea Ice area for the period between 1st Jan 1979 and 31st Dec 2008 was 10.001 million sq kms.

By way of comparison, here are some rolling 365 day averages from the same source...

1st Jan 2013 - 31st Dec 2013, average SI area = 9.214 million sq kms
1st Jan 2014 - 31st Dec 2014, average SI area = 9.103 million sq kms

19th May 2014 - 18th May 2015, average SI area = 9.088 million sq kms

As you rightly point out, 2011 & 2012 have been conveniently expunged from their collective memories.

1st Jan 2011 - 31st Dec 2011, average SI area = 8.747 million sq kms
2nd Jan 2012 - 31st Dec 2012, average SI area = 8.671 million sq kms

(20012 was obviously a leap year, and the 366 day average was 8.679 million sq kms.)

That's why they're more accurately referred to as "fake sceptics".

Could you be so good as to indicate the source of this egregious claim? There could be some fun in the offing.

Cheers Bill F

[Bill Fothergill]

Oops! Proof reading failure.

My penultimate sentence in the above post should have read...

It took me all of about 5 minutes to calculate these numbers, that's why they're more accurately referred to as "fake sceptics".

[wayne]

Jim, was wondering if you can pin point exact location of snow and ice interface, as well as water and ice interface given that official buoy ice depths are somewhat difficult to reconcile with official thicknesses, especially with respect to "A" and "D"....

[Paddy]

@Bill,

The discussion was a long and messy one in the comments on a blog article... somewhere. I remember they based their argument on this graph (or at least the most recent part of it) though: http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/global.daily.ice.area.withtrend.jpg

[Lennartvdl]

Colorado Bob, thanks for the link to the Alley-lecture. I reposted it on the ASIF.

[Bill Fothergill]

@ Paddy

I see where we are at cross purposes. The link in your first post is broken, and, subconsciously, I simply tuned in on the first part of the URL - namely "Arctic". Mea Culpa.

Again however, this just goes to demonstrate the fake scepticism that is so prevalent whenever climate change is discussed. Using the CT database, the long term average (1979-2008) for global sea ice area is 19.001 million sq kms. The 730-day rolling average over the 2013 - 2014 period is actually 19.145 million sq kms, or 144 thousand sq kms above the long term average.

The argument that this somehow shows global warming isn't happening is a mixture of verisimilitude and stupidity.

Verisimilitude is a noun, and relates to something which, as an assertion, merely possesses the appearance of being true - as opposed to actually being true. The Arctic and Antarctic are, literally, poles apart: therefore, as we live on a planet which displays pronounced obliquity (or axial tilt - currently about 23.4 degrees and dropping) the poles have seasons which are in complete anti-phase.

It therefore seems completely logical - because it is completely logical - that as sea ice coverage goes up at one pole, it must therefore be expected to reduce at the other. However, this behaviour simply demonstrates the seasonality differences between the boreal and the antipodean parts of the planet - and that's where verisimilitude comes into the picture.

The stupidity comes in when this perfectly logical view is extended to account for long term variations in the averages at either end of the planet. Perhaps I can explain this best by means of an analogy.

Imagine a parent taking his (or her) twins to the doctor's surgery because one child is running a temperature. To the parent's amazement (and doubtless consternation as well) the doctor examines the second twin and declares that, since twin number 2 is hypothermic to the same degree that twin 1 is hyperthermic, then there is no need for concern as, taken together, their combined temperatures are normal.

Under such circumstances, the parent would be perfectly entitled to question not only the doctor's competence, but his/her sanity.

Under such circumstances, not only would the doctor be facing imminent disbarring from the profession, but he/she would be staring down the barrel of a serious lawsuit.

I wonder how long it will take us to get to that stage. Sadly, I suspect it will be too late for the generations to come.

Cheers Bill F

[D]

The problem, Bill is that the thermohaline circulation in the Weddell Sea has collapsed. It stopped producing the coldest water in the global oceans in the late 1970's. Deep water formation is down 20%, and possibly more, around Antarctica. Warm intermediate water is melting the ice cap from below producing a fresh water layer on the surface.

In winter, ice forms and serves as a thermal lid. Climate deniers are totally misunderstanding the increasing winter ice around Antarctica. Summer sea ice around Antarctica never amounted to much so, again, the slight increases in Antarctic summer sea ice don't in any way offset the large decreases in Arctic sea ice. Ocean heat content is rising in both the Arctic and Antarctic.

-FishOutofWater, aka George

[Chris Reynolds]

I've been looking at Beaufort/Chukchi/East Siberian Seas, a region I call the BCE region.

For the BCE region, the 2007 to 2012 period has an average September extent 14% of that for the 1980s. For comparison with the whole Northern Hemisphere extent, 14% of the 1980s average would be 0.979M km^2, which fits the commonly accepted definition of below 1M km^2 for which the Arctic be considered virtually ice free in September. Therefore BCE can be considered virtually ice free in September for the period 2007 to 2012.

[Burnrate]

When I read

"The only thing we know for certain, is that the Arctic won't see below 1 million km2 of sea ice come September, ..."

I thought, oh no, he made definitive prediction; we are going to see an ice free arctic this year! :(

[Colorado Bob]

'Epic' flooding on Dalton Highway hinders North Slope oil operations

DEADHORSE -- Unprecedented flooding continues to interfere with daily operations on the North Slope oil patch after surging waters wiped away swaths of the Dalton Highway and isolated a section of Deadhorse, the jumping-off point for the sprawling industrial region.

“This is just epic,” said Mike Coffey, commander of the unified incident command, a response team consisting of the state, the North Slope Borough and oil companies. “People who have been here for decades say they’ve never seen anything like it.”

https://www.adn.com/article/20150521/epic-flooding-dalton-highway-hinders-north-slope-oil-operations

Look at photos they are amazing.

[Colorado Bob]

The forecast for Fairbanks , Ak.

89F degrees.

http://www.wunderground.com/weather-forecast/zmw:99701.1.99999

This heat goes all the way to delta of the MacKenzie River.

When the sun come up tomorrow, thousands of square miles of tundera will be exposed to above 80F degrees in May.

[Bill Fothergill]

@ George/FOOW/D

No argument from me on most of the points you made, but I've long suspected that the gradually increasing Westerlies way down there are at the heart of the matter.

Eric Steig wrote an article at RC last year that represents time well spent in the reading...
http://www.realclimate.org/index.php/archives/2014/12/clarity-on-antarctic-sea-ice/

Of particular significance is the direction of Coriolis deflection: in the antipodes, the Westerlies will produce a bulk movement to the left - i.e. in the direction of the equator - hence the spreading.

Also, mass balance losses from the massive ice sheets help create a less-dense "fresh water lens", with its concomitant higher freezing point.

Also, also, higher air temperatures in the South Pacific/Southern Ocean in conjunction with the Clausius Clapeyron relationship leads to greater moisture content in the air - which leads to greater precipitation and hence further freshening. (Think of the directions of surface level and high level flows in the SH Polar Cell.)

The one aspect that needs to be looked at closer is the overall albedo effect of the reduced summer ice in the NH and the increased summer ice in the SH.

Although the positive delta in the SH is much less than the corresponding loss of ice in the NH, size isn't everything. There are two other important factors which need to be considered...

1) Antarctica itself sits more or less straddling the South Pole. As the area of the white continent is about 14 million sq kms, this means that the sea ice only starts at about 70 degrees South, and extends northward from this margin.

I therefore think that, for most of the SH sea ice, the antipodean summer sun will be higher above the horizon than that experienced during boreal summer.

2) At our present phase in the Milankovitch cycles, perihelion (closest approach to the sun) occurs on about the 3rd January. Insolation at this time is about 7% higher than at aphelion (Earth's furthest distance from the sun), which occurs on the 4th July. (Sorry about that, USA)

Without crunching the numbers, I therefore don't know if it's safe to simply dismiss this particular aspect of denialist folklore. (Let's face it, if they make up enough stuff, something might actually make sense once in a while - even if the correct reasoning is beyond them.)

Cheers Bill F

[D]

The tightening of the westerlies is caused by the poleward expansion of the subtropical high pressure areas and subsidence from tropical convection. It also tightens up the Antarctic Circumpolar Current (ACC) around Antarctica.

Yes, this tightening is a key factor in changing both the wind fields and coastal currents around Antarctica. Multiple papers have been published on this and they paint a consistent picture. This change in winds drives more upwelling and less deep water formation.

Yes, more precipitation and more melt water are also important in creating a fresh water layer than freezes up over a larger area in winter.

[D]

Bill, did you see this paper:

http://www.the-cryosphere.net/8/1289/2014/tc-8-1289-2014.pdf

which finds that much of the apparent growth of Antarctic sea ice is the effect of a change in the method of analysis of satellite imagery?

[VaughnA]

Bill F.,
if I am remembering correctly the northern hemisphere summer is about 4 days longer than the northern hemisphere winter thereby making up for the greater distance from the barycenter of the solar system. The opposite is true in the southern hemisphere...winter is about 4 days longer and summer about 4 days shorter.

Remember also we actually orbit the barycenter of the solar system instead of just the sun. This also causes variability in our distance from the sun as well as variability in solar input as the sun also orbits the barycenter as well. Of course, over time this all averages out but can cause variability over the span of several years.

Right now the barycenter is beneath the surface of the sun so variability is smaller. Starting in 2017 the barycenter will be moving outside the sun for a number of years increasing the effect of this variation.

https://tallbloke.wordpress.com/2011/01/14/gerry-pease-barycentric-orbital-periods/

[wayne]

I offer this article:

http://eh2r.blogspot.ca/2015/05/dedicated-sea-ice-model-proofing.html

to the hard working sea ice model physicists in particular to check if their temperatures profiles match what is observed by the refraction
method. I have not seen any similar figures in the literature. I would useful to see one for verification purposes...

[Bill Fothergill]

@ D (or any other alias)

Re: The cryosphere-net paper.
Yep, I read that one a while ago, and, like any other single study, I don't know how much to read into it. I haven't seen any "robust debate" on the paper's methods and conclusions, and I certainly don't know enough about the details to have a worthwhile opinion on the matter.

That said, the recent CT figures strongly suggest that, even if the findings of Eisenman, Meier & Norris are fully vindicated, things are still changing way down there.

The CT Antarctic annual average sea ice area values for 2008 (9.48 million sq kms), 2009 (9.36), 2010 (9.37) and 2012 (9.42) were all above average, but not really remarkably so. Up until that point, 2008 had seen the highest value in the dataset.

However, 2013 (9.89) and 2014 (10.08) blew the record away. The recent jump seems far too large to be accounted for by the mechanism proposed in the EMN paper. I also remember that an Australian Ice Breaker was experiencing problems with high levels of ice a year or so ago. (Can't recall exactly when.)

But, hey! What the hell do I know?

Cheers Bill F

[Bill Fothergill]

@ Vaughn

Yep, you do recall correctly (something I am having increasing difficulty with these days) when you say that the boreal "summer" is about 4 days longer than its austral equivalent.

However, that figure is based on the length of time between successive equinoxes, in that the approx 6 month period spanning perihelion is indeed shorter than the equinox - equinox spanning aphelion. Welcome to the wonderful whacky world of Kepler's Laws of Planetary Motion.

Kepler's 2nd basically states that, for any given planet, a line segment joining the planet & the sun "sweeps out" equal areas in equal times. As it "falls" towards the primary from the aphelion point, any planet gradually picks up velocity, until, at perihelion, it reaches its peak value. On the outward jaunt from perihelion back to aphelion, this velocity delta is gradually shed.

To a reasonably good approximation, at any point in its orbit, a planet's orbital speed is just about inversely proportional to its distance from the sun.

However, and I apologise for not wording this better in my original comment, I was specifically thinking about albedo effects close to the time of maximum insolation - say about 4-5 weeks either side of the summer solstice.

On various early threads, there have been ruminations about the possible effects of a low Arctic sea ice level by, say, the beginning of June. I should have made it clear this was the kind of situation I was thinking about. mea culpa

Regarding the link about barycentrism: yep, I'm well aware of this. An orrery is a great teaching device, but it comes at the cost of possible over-simplification.

Of course, judging by the blogroll down the LHS (or possibly make that "bogroll") I rather suspect the blogger in question would like everyone to believe that climate is controlled by absolutely anything - as long as it isn't a triatomic molecule containing one carbon and 2 oxygen atoms.

Back when I was naive enough to think that WUWT actually was interested in genuine scepticism, I seem to remember there being someone with the moniker "tallbloke". One and the same, perhaps?

Cheers Bill F

[EthonRaptor]

Thanks for the update

Eli

[Bill Fothergill]

@ Vaughn Re: Tallbloke link

Tamino did a hatchet job on the idea that planetary alignments were in any way linked to climactic changes...
https://tamino.wordpress.com/2012/03/22/mathturbation-king/

When the moon is in the 7th House, and Jupiter aligns with Mars - or something like that.

Even arch deniers, such as Lubis Motl, have put the boot in...
http://motls.blogspot.co.uk/2014/03/barycentric-climatology-was-never-good.html

Even Anthony Watts was moved to write...
"Oh, people will still debate it I’m sure. Tallbloke and his group of cyclists will try to prop it up, but I’d say it pretty much has reached the end of credulity as a workable theory."

Cheers Bill F

[VaughnA]

Bill, in case you missed it in my previous comment:

"Of course, over time this all averages out but can cause variability over the span of several years."

I am in no way suggesting this causes any type of long term trend, only temporary noise that averages out due to some variability in our distance from the sun over the short term. I am not even suggesting this is the major source of noise. I won't bore you with a list like that because they have been and continue to be well discussed here.

It's probably more about me thinking artifacts like this are cool especially since this is one of the ways extrasolar planets are discovered.

[Jim Hunt]

A picture of Seasonal Ice Mass Balance Buoy 2015A sitting in the midst of melt ponds. The buoy is located on landfast ice in the Beaufort Sea near Prudhoe Bay:

Click the image for a closer look.

[Bill Fothergill]

@ Jim

There is an old saying (possibly from the former UK Prime Minister, Harold Wilson) that "a week is a long time in politics". Judging by the differences in the photos from the 16th and the 23rd, it's a bloody long time in the Arctic as well.

@ Vaughn

My post timed at 18:16 was purely meant to demonstrate the precise level of credence that should given to the tallbloke blog.

cheers bill f

[VaughnA]

Bill, I've never seen or heard of the tallbloke blog before you mentioned it. I have gotten all my info from astronomy resources that were mostly concerned about the mechanics of the motion. I think the topic is very interesting; however, I agree the effects on climate are ephemeral and swing both ways over a short time scale with a NET effect for all intents and purposes "0."

[Sam]

I agree that in terms of global warming, the barycentric argument is grasping at straws to try to in some way excuse continued inaction and profit making while the world burns.

However, we should not then throw the baby out with the wash water just because that is a bad argument. Doing so would echo the opposition to J. Harlan Bretz noting the factual and extremely important evidence of massive cataclysmic floods on the Columbia Ricer on the basis that flood catastrophism is religion and we are doing science. That was foolish and wrong headed.

I believe we would be equally foolish and wrong headed to discard barycentric astrophysical arguments on the basis of fallacious arguments trying to avoid blaming humanity for global warming. Likewise, reducing the arguments to gravitational tidal affects is also wrong.

The complex orbital dynamics clearly occur and cannot be avoided in a multi body system. Gravity and resulting accelerations are important. But so too are conservation of linear and angular momentum (both orbital and body rotations) and the first, second and third order moments of inertia and the complex impacts on these. These lead to complex changes in torque and rotational accelerations, as well as drifting changes in the orbital parameters of all of the bodies involved. In the near term, these will at the least appear to average out. Howeve, the situation is made more complex by the non average deviation from baseline and most importantly by fluid dynamics.

This is especially true for that big gaseous object we call the Sun. It is abundantly clear that the combined orbital oscillations of the Sun, Jupiter and Saturn, and to a lesser degree the other planets drive the solar atmospheric circulation. Even minor torque changes disrupt that systems stability and gaseous distribution and flows, as well as the main solar sun spot cycle. Holding those minor imbalances for years creates a bias that moves a lot of parameters. It is not at all surprising this results in major impacts in the solar atmosphere, and consequently to earth in a variety of ways.

The end effect is quite observable in the solar minima cycle in sun spots. This is less dramatic than the main cycle, but none the less important, as some minima can lead to a very quiescent sun for prolonged periods. And, that can have somewhat large climatic effects (e.g. The little ice age).

Even though we are smack in a solar minima, that is not happening now. Let me repeat, that has happened before, but is not happening now. This minima is a relatively mild minima, which serves to lengthen and lessen the expected cycle. The reality is much more complex though and will extend over two to three cycles.

What I do find interesting are two things.

First, a good understanding of these cycles and their effects could lead to a vastly better retrospective model of the past, which could iron out some of the minor discrepancies or more properly irregularities that exist between observations and the modeling (which include the larger 22,000 - 25,000 year cycles of precession, insulation, movement if the nodes, oscillation of the polar tilt, etc...).

Second, I am perplexed that so many astronomers seem to be either completely unaware that this issue exists, or adamantly opposed to it based on what appear at least to be either anti religious, anti political or overly simplified physics arguments. It us all too easy to try to simplify the complex orbital systems to simple gravitational effects. And I am sympathetic to a degree, as the arguments of the denialists do often seem like a never ending barrage of gibberish.

The Suns orbit is so perturbed by the planets, that it is quite fair to say that much of the time, the Sun itself orbits the vacant barycenter of our solar system. At other times the barycenter is near the center of the Sun.

And as anyone who has ever played on or around the center of a merry go round can attest, moving in, over and out of the center can have huge dynamic affects and in the case of humans can result in severe vomiting.

Now what does any of this have to do with the polar melt? Well, I would argue that during the little ice age it had a significant impact deepening the freeze and altering climate and weather. I would argue that it is having a very small effect during this minima. Worse, whatever effect it is having is serving to mask the effects of human caused global warming, meaning that it is leading to a lessening of the warming impacts at the worst possible time.

In no way is it, or can it, lead to a sharp increase in warming as we are seeing since the 1960s or so. What it can do is provide a slightly dampening of the apparent warming, leading politicians and profiteers and denialists to rage for more inaction all the while momentum builds and a faster rate of change is locked in for the future. And I again emphasize that this is a mild solar minima.

Sam

[Kris]

Jim Hunt wrote:

The buoy is located on landfast ice in the Beaufort Sea near Prudhoe Bay:

The picture coming from camera 2 is even more impressive. Do you know whether this camera 2 resides at the same location (Prudhoe Bay) or not? “Washington Edu” doesn't look very communicative about ..., albeit to me.

[Bill Fothergill]

@ Vaughn
"Bill, I've never seen or heard of the tallbloke blog before you mentioned it."

Please look at the link contained in your post timed at 06:49 on May 23rd. I think you'll find it is rather at odds with the above assertion.

[Jim Hunt]

Kris - That camera is looking at IMB 2015B, currently located in the Chukchi Sea. Much more info at:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/summer-2015-imbs/#2015B

[wayne]

And here you have it, 2015A

http://imb.erdc.dren.mil/irid_data/2015A_clean.csv

will swim with the fishes soon, if its loss of 30 cm at bottom, from 05/23/2015 20:00 to 05/24 04:00 UTC, was accurate. At about 1 C outside temperature not much more. The rot at bottom makes it so, for quite a while the bottom melted and refroze, a process that can be seen if you drill through the ice. The continuous phase changes created mushy soft ice boom layers likely more porous, where micro-creatures hide from krill. The tides played a role as well with likely warmer water moved in.

I think the speed of sea ice melt is set in no small part by pre-existing conditions, which are not favorable for sea ice to last when insolation spans long periods.

http://eh2r.blogspot.ca/2015/05/dedicated-sea-ice-model-proofing.html

[Jim Hunt]

Wayne - I've never been able to tie up the thermistor and bottom sounder readings from 2015A satisfactorily, since the sudden jump in April at least. Here's the latest temperature profiles:

Click the image for a closer look.

Based on the thermistors I see no evidence for an inrush of warmer water or the sudden onset of bottom melt. Whatever the bottom sounder pings were being reflected off seems to have gone. Other than that, the core temperature of the floe is still below "melting point", so I don't expect to see any sudden changes just yet.

[Bill Fothergill]

@ Wayne

So, you decided that "2015A" was a boring sort of name, and that we should now refer to it as "Luca Brasi".

;-)

[Kevin O'Neill]

Jim, the top meter of ice on 2015A has warmed by an average of 1.34 C over the past 10 days. The core is now just 0.7C above the water temperature.

If the next two weeks are like the past two weeks the ice will be isothermal and the buoy will indeed be swimming with the fishies shortly thereafter.

[Jim Hunt]

Kevin - I did say "just yet"!

Have you seen this temperature profile from last summer?

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/summer-2014-imbs/#2013F

Buoy 2013F is still with us this summer:

http://GreatWhiteCon.info/resources/ice-mass-balance-buoys/summer-2015-imbs/#2013F

[Kevin O'Neill]

Jim, 2013F was/is more than 350 miles north of 2015A. At this time last year 2013F still had 0.8m of snow on it and through all of last summer 2013F only saw 700 hours of above 0C air temperatures - only 33 of them in May. By contrast, 2015A has already seen 200 hours of above 0C air temperatures in these first three and one-half weeks of May.

The difference in latitude is quite important as is the snow depth. I'll be surprised if 2015A isn't in swim mode a month from now.

[Jim Hunt]

Kevin,

Forget the differing dates and latitudes. Consider the temperature profiles. My point is that even when an ice floe has become "isothermal" as far as the thermistors are concerned it doesn't vanish overnight, or even in two weeks.

Do you fancy a little flutter? ;)

[wayne]

Jim , correct I couldn't reconcile the thermistors data with sonar for the longest time. I suppose they decide thickness by sonar rather temperatures. However In A's case consider the top point where the ice was just below zero at 08:00 UTC which is thermistor 6, and thermistor 22 where -1.8 C has been recorded likely the bottom.
Which was not always the bottom warmest thermistor of record, most times is thermistor 19. I think the bottom is messed up, although we need a visual confirmation, its the the time when krill must work harder to get din din.

Yes Bill, Brasi buoy is more apt!

[Bill Fothergill]

Judging by the NSIDC and ADS VISHOP numbers posted for the 24th of May, it looks a virtual certainty that both these metrics will still be showing 2015 in record low territory come the beginning of June.

Given that it will still be almost 3 weeks shy of the solstice, there should be a few more joules going into the ocean.

[Robert S]

There is currently an extremely odd little area of fractured ice between the north east coast of Ellesmere and the north coast of Greenland, surrounbded by what seems to be immobile/fast ice. What is the dynamic that could cause this effect? https://earthdata.nasa.gov/labs/worldview/?p=arctic&l=MODIS_Aqua_CorrectedReflectance_TrueColor(hidden),MODIS_Terra_CorrectedReflectance_TrueColor,Reference_Labels(hidden),Reference_Features(hidden),Coastlines&t=2015-05-21&v=-334809.2698409726,-842860.0705504486,-89049.26984097261,-722156.0705504486

[VaughnA]

Bill,

According to what I am seeing about barycenter is we currently vary about 0.8 radii of the sun with corresponding radiation gain when closer and equivalent loss when roughly this distance further away a half year later. This is independent of seasonal distance and is quite small. It looks like it will max out at about 1.6 solar radii in 2022-2023. The earth should get equivalent increased and decreased radiation over the course of each year with a net difference of "0" as both of us have been saying. I am not quite sure why you are saying my "0" is different from your "0."

This is getting off topic, so it is probably not worth discussing further on this blog since the effects are as you say non existent or too small to measure.

[Jim Hunt]

Robert - That's the northern end of the Nares Strait, through which flows lots of water. I posted a similar image recently on the ASIF forum:

http://forum.arctic-sea-ice.net/index.php/topic,176.msg52621.html#msg52621

We're idly wondering over there when lots of ice will start flowing through it also.

P.S. Another pretty picture of mine has been stuck in your moderation queue for a couple of days. See the one above.

[wayne]

Returning to 2015A

http://imb.erdc.dren.mil/irid_data/2015A_clean.csv

in fog brings out reality, with top 5 shielded by cloud thermistors measured an inversion a 260800 and 261200.
Note the small temperature differences especially with the surface reading, this small difference is enough to raise the horizon. Buoy thermistors readings in the sun become very suspect when the temperature differences between surface measurement and above ice string thermistors are very large. But the visual observation is prime and is not affected by instrumentation artifacts. This is why its important to be as correct as possible when verifying with models.

http://eh2r.blogspot.ca/2015/05/dedicated-sea-ice-model-proofing.html

On a sunny day, if top string thermistors did not have solar induced artifacts they would measure very close to an isothermal profile as observed when the sun is high enough. When the sun lowers to midnight an inversion is created because the ice is colder than the air. This is not quite the same as air being cooled by land in the morning after night time at Southern latitudes. The ice cools the air at first chance it gets. For those who drive on a hot summer day right after twilight on a highway, you can still see road mirages by distant car red back lights doubling on pavement, if the road was ice, it would not be seen likewise, the red lights would be raised without cognizance.

[Colorado Bob]

Has the Last Human Trekked to the North Pole?

Faced with a dearth of logistical support and challenges related to climate change, human-powered trips to the North Pole may be on the brink of extinction.

"North Pole expeditions are going the way of the passenger pigeon," says Eric Larsen, a Colorado-based polar explorer who has completed three North Pole expeditions.

" You're camping on thin ice and to me that's dangerous. It's thin, and it moves in the middle of the night. Nothing's going to stop it from cracking under your tent. "

[Bill Fothergill]

@ Bob,

How about kayaking trips to the NP in the not-too-distant? One could play tag with the belugas en route.

Since they appear to be gripped with gambling fever, perhaps Jim, Chris or Kevin might care to lay odds when such a venture could start?

[Kevin McKinney]

"How about kayaking trips to the NP in the not-too-distant?"

Now, *that* should garner some headlines! But, conservative me, the flutter of excitement should be quite enough… though I will certainly watch any punters who ante up with interest.

[Jim Hunt]

Bill - Well, Anne Quéméré is going to attempt to kayak through the Northwest Passage once again, following her abortive attempt last year:

http://www.anne-quemere.com/?lang=en

A couple of years ago I spoke to Anders Bache of the Fram Museum in Oslo, who assured me he knew of a team planning to kayak to the Pole itself.

http://forum.arctic-sea-ice.net/index.php/topic,116.msg1621.html#msg1621

Who knows, maybe this will be the year?!

[wayne]

JIm, I hope they plan to come back with kayaks as well, since pilots may refuse to land at the Pole if the ice is too thin. In the recent past, NP pick ups were always preferred on multi-year pans, now is only Borneo. The reason for thick ice make-shift runways may be understood by the DeHavilland plane which sank at the Pole when it landed on First year ice in the 80's. So one day, someone will film a plane at the bottom of ocean very near a Russian flag.

[Kris]

Jim Hunt wrote:

... to attempt to kayak through the Northwest Passage once again

According to her website it's rather the Amundsen route, which is of course one of the possible Northwest passages.

[wayne]

Does anyone have a schematic of string thermistors as installed with current mass buoys?

[Kris]

The Pacific and central parts of Alaska look bound to be baked too. So already now we know 2015 will be remembered as a hell of an inferno ...

Unusually hot and dry weather will settle into southcentral Alaska beginning Friday through the weekend. High temperatures will stretch from the mid 70s to mid 80s throughout the region with the hottest day likely occurring on Saturday.

Sea breezes which usually moderate afternoon temperatures will be limited during this timeframe. Also periods of gusty winds in Seward, Whittier and Valdez will aid in warming temperatures even further.

[Jim Hunt]

Wayne - If by "schematic" you mean what we call a "circuit diagram" over on this side of the Atlantic then I'm afraid I don't.

How would having one help?

[Kevin McKinney]

Wayne, I don't, but apparently Woods Hole does, though not the very latest:

http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CB8QFjAA&url=http%3A%2F%2Fwww.dtic.mil%2Fcgi-bin%2FGetTRDoc%3FAD%3DADA274499&ei=dGxoVYO4CcilsAWj7YOADw&usg=AFQjCNHqayYkP7KE5yV8sESLbbYFigfShQ&sig2=XIKn0poQsRBrtl-CL6m_nA&bvm=bv.93990622,d.b2w

Hope that helps...

[wayne]

Jim, Kevin Thanks but I am looking for how the thermistors are installed.. On a simple wire string? Or from what it seems, in a vertical plastic tube , where as at installation water fills a vertical pipe and freezes thereafter. The schematic was nice but was for O' buoy's.

[Espen Olsen]

We just had a seasonal around the 1st of June calving at Jakobshavn:

https://forum.arctic-sea-ice.net/index.php/topic,154.msg52916.html#msg52916

[Jim Hunt]

Wayne - 2015A is a "seasonal" IMB buoy. Diagrams are available here:

http://imb.erdc.dren.mil/SeasonalIBinst.htm

and in this paper:

http://imb.erdc.dren.mil/pdfs/SIMB.IGS.Final.pdf

[wayne]

Thanks Jim,

Is a familiar problem but instead of snow , ice., water or air its plastic:

"For comparison, a thermistor string of the same design used in the IMBs, also deployed in a ponded area, melted out even sooner (g),"

What appears to be faster melt caused by the instrument may be explained by the material used, plastic, or PVC which has half the heat capacity of ice or snow. This means for every joule of kinetic energy about this material would gain temperature twice as fast. Now I think that refraction method supersedes buoy thermistors in "absolute" quality by several levels of magnitude.

1) Sea ice naturally reflects light, but during mid to late spring, top of it is usually colder than air, this implies an immediate above ice surface air inversion. Which is nullified with sun rays, but not enough to cause a "road mirage" , like a paved surface, in fact sun rays SW warm the ice column (which in turn affects the thermal balance throughout the ice which if strong enough causes it to melt at bottom), so a very near air isotherm is created until the sun lowers to a critical point when the inversion returns immediately. This critical point is dynamic and depends on how long sun rays have bombarded the ice.

2- In darkness of the long night when sun is completely removed, my next subject to write about, there seems to be nothing but above ice/snow surface inversions unless there is cold air advection, which is relatively infrequent, so top of sea ice thermistors must record more often than not inversions during the dark season. I have never recorded a pure isotherm horizon during the dark season yet, like when its sunny at noon during spring. This suggests that LW radiation from the sea overwhelms even cold air advection and thickening ice to the point where surface adiabats should be rare or possibly improbable. At least for now -yet to be observed-

[Jim Hunt]

Whatever the cause might be (maybe the Colville River?), buoy 2015A suddenly finds itself sitting in a bath of much warmer water. Perhaps unsurprisingly the bottom of the ice has melted a bit more:

Click the image for a larger version.

[Ghoti Of Lod]

Isn't it odd that the temperatures below the ice are so far above -1.8C? This has to be rather fresh water. I presume that's why you suggest it might be river water.

It also might be from surface water draining down the hole made for the thermistors which would mean it is a misleading artifact.

[Colorado Bob]

Hell is coming to breakfast , everyone buckle their chin strap.

[Colorado Bob]

The dead from Texas Floods are being found 34 miles downstream.

[Kris]

GOL wrote:

above -1.8C? This has to be rather fresh water

How come? The chart indicates -1,8 ºC and not above. And fresh water freezes at -1,8 ºC, doesn't it?

All the more as the “suddenly” Jim talks about spans from 5th May till 24th May. And as we all know, the “heat wave” hitting North-East Alaska and the Mac Kenzie region began around the 1st of May.
So defenintely it's sea water there, or, to be more specific, briny water due to the fresh water coming from the Colville and other off coast running melt water.

[Pjie2]

Uh, are you missing the trace from 30th May that shows the water under the ice as hovering about -0.2 degrees?

[Kris]

Talking about Alaska's Colville river, look at Permafrost melting at Colville River Bluff to see a devastating result of melting permafrost.

[Kris]

Pjie2 wrote,

are you missing the trace from 30th May

Yes I did.
Nevertheless, is the water is already fluid at -1,8 ºC while warming up we rightly can assume it isn't fresh water, can't we? For sure the mass of water coming from the Colville has forced temperture upwards, still, a mix of salt water with fresh water remains brackish (or briny) water.

[Pjie2]

Without seeing more traces from between 24th/30th I don't think we can say.

All we know is that currently there appears to be a lens of fresh (or very nearly fresh) water under 2014A. We don't know where it came from or how deep it goes.

It could be localised melt pond drainage - probably not directly down the thermistor string though as otherwise you'd see the temperature rise all the way along the string. Could also be river outflow pooling under the ice.

If the thermistor string was long enough we could distinguish the two, since I imagine localised drainage would form a pool a few tens of cm deep at most, whereas river outflow might form a thicker layer.

[Jim Hunt]

Although not shown in the graph above, the water temperature started to increase on the 27th, and is consistent all the way down to thermistor 31, i.e. getting on for a meter. See also:

http://forum.arctic-sea-ice.net/index.php/topic,1149.msg53038.html#msg53038

It certainly isn't drainage of melt water down the side of the buoy itself.

[Bill Fothergill]

"What appears to be faster melt caused by the instrument may be explained by the material used, plastic, or PVC which has half the heat capacity of ice or snow. This means for every joule of kinetic energy about this material would gain temperature twice as fast."

Wayne, whilst the above statement seems reasonable enough at first glance - it doesn't adequately capture the physics, specifically the energy transfer rates.

As you know better than me, the thermistor string is encased in a plastic (or PVC, whatever) sheath, which is itself buried within the ice column. Owing to the massive thermal inertia of the ice sheet (or floe), the temperature profile is pretty well determined by the ice, not by the buoy.

It is possible that one could get an anomalous temperature profile if the thermal conductance of the introduced material was sufficiently high. However, the thermal conductance of PVC is typically just under 10% of that of ice.
(The values are about ~ 0.19 Watts/metre-Kelvin as opposed to ~ 2.19 Watts/metre-Kelvin.)

So, although you are correct about the relative Specific Heats, the energy transfer rate straight down (or up) through the PVC sheathed thermistor string would actually be much less than the equivalent transfer rate through the ice. Hence, one would not expect to see any significant rate of change of temperature owing to the differing material.

As regards those thermistors located above the ice, yes, they might respond fractionally faster owing to their lower SH. On the other hand, they might instead respond slower due to the low thermal conductivity of the encasing protective sheath.

NB: If the PVC sheath was very thin, and there was a nice thick electrical conductor - with high thermal conductance - running down the middle, that could make a slight difference. However, the temperature profile of the ice should still dominate in either event.

NNB: Thermal conductance can appear to have seriously weird units - Watts/metre-Kelvin. The trick is to work through the logic: the total (steady state) energy transfer rate is directly proportional to the surface area and the temperature differential, but inversely proportional to the thickness of the material. So, when you multiply the conductance by the area (metres squared) and the temp differential (Kelvins), and then divided by the ice thickness (metres) - lo and behold - what pops out of the equation is Watts. (Not him!!!!)

cheers bill f

[Chris Reynolds]

Bill, I agree.

If it is reasonable to assume that within the thermistor bead the heat is going nowhere, which I think is the case (as do you). The insulation of the sheath merely affects the time taken to respond to changes in temperature.

If readings are taken only once at the same time in a 24 hour cycle this might induce an error due to shadow moving over the string where it is exposed to the air just before the time of measurement. Otherwise it can be neglected. In the case of thermistors in ice or water the large thermal mass of those bodies means the effect can probably be safely neglected.

[Sam]

Wow.

The minor fracture off Ellesemere is now a major fracture that extends all the way from the Beaufort Sea to the Atlantic.

http://1.usa.gov/1LUvmyJ

The thick land fast ice is now completely free to move with the wind and currents. The last remaining piece that had only narrow fractures was the part over Ellesmere. Not any more. This should be an amazing melt year.

[wayne]

Bill and Chris, Interesting comments. You must start with the premise that the thermistor string helps melting sea ice faster. And work on the reason from there. I would use a material or no material, but first a material equal to SH of ice. Different plastics have various SH. As far as conductance is concerned it depends whether the string pipe is filled with material or hollow with air. Either way need be studied. Ideally the instrument should not affect the medium it measures.

Camera 2015A must focus at open water hole (may be there is one) to see if it is river water or tidal flows which is bringing about already very much warmed up near by sst's.

[Bill Fothergill]

Wayne, you are working from the proposition that...
"You must start with the premise that the thermistor string helps melting sea ice faster"

However, you might be skating on thin ice (tee-hee) with that one, as you have not provided justification for making such a statement. I'm not saying that isn't the case, just that you haven't (yet?) made the case.

If such melting does indeed happen, one might reasonably expect the buoy (and its encased thermistor string) to gradually slide down through the ice. My knowledge of the mechanics is too meagre to know if this indeed happens.

As I mentioned, the limiting factor as regards response time is almost certainly going to be the thermal conductance (k) of the assembly - specifically the outer sheath, as this is the means by which the buoy is provided with its structural integrity.

The differing Specific Heats (SH) of the constituent parts versus that of the surrounding ice has, at best, a second order effect on response times.

If you only require half the energy (SH), but the energy transfer rate (k) is one tenth, then the response time is going to slow down by a factor of five.

Yes it is true that it could easily be hollow, i.e. air filled. However, this would simply reduce the conductance by yet another order of magnitude. The k value for air is ~ 0.024 Watts/metre-Kelvin.)

Typical conductance values for a range of materials can be found at...
http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

cheers bill f

[wayne]

Bill, I was not my conclusion, but from the paper linked by Jim.
It remains wise to be skeptical of some of the MB temperature data, and especially know its limitations more.

[Colorado Bob]

Climate scientist Paul Beckwith reports on recent spikes in Arctic methane:

Arctic methane skyrocketing.

https://www.youtube.com/watch?v=p2ckkxEnWpAJenny Loveitt

[Colorado Bob]

New paper by Prof. Francis

Rapid Arctic ice loss linked to extreme weather changes in Europe and US

http://www.theguardian.com/environment/2015/jun/01/rapid-arctic-ice-loss-linked-to-extreme-weather-changes-in-europe-and-us

[Boa05att]

Special issue in 'Philosophical Transactions of the Royal Society A' on "Arctic sea ice reduction: the evidence, models and impacts"

http://rsta.royalsocietypublishing.org/content/373/2045?current-issue=y

[Bill Fothergill]

Bob has just linked to a video featuring Paul Beckworth (from the Arctic Methane Emergency Group - AMEG) talking about recent - i.e. since 2000 - rises in methane levels.

AMEG gets mentioned from time to time on this blog, but those unfamiliar with views held by AMEG members may care to have a look at...

http://www.ameg.me/index.php/about-ameg

and...

http://arctic-news.blogspot.co.uk/p/about.html

AMEG represents one end of the spectrum when it comes to how concerned we should all be about the destabilisation of methane clathrates in the Arctic. I think it's fair to characterise people such as David Archer as being far more relaxed about the impact.

I don't profess to know enough about the topic to have a strong view one way or the other, but any additional positive feedbacks at least deserve to have an eye kept on them.

cheers bill f

[Chris Reynolds]

Wayne,

"not my conclusion, but from the paper linked by Jim"

This paper?
http://imb.erdc.dren.mil/pdfs/SIMB.IGS.Final.pdf

Can you give me a string I can use to find the relevant part? I'm too busy to read the whole paper. The string shown in figure 1 will cause a very limted effect, the question regards the new system (fig 2) is much more complex!

I should point out - the lab I manage does temperature calibration. When I agree with Bill I do so with practical knowledge of similar problems in getting the best precision from baths, and zero point cells.

[Chris Reynolds]

Wayne,

I've just scanned it very quickly.

The Results section suggests to me that the new design exhibits substantial melt due to solar heating. But this might be due to deployment in a melt pond. It is unclear whether the other IMB referred to is a traditional type with a thin thermistor string.

In terms of the thin string of thermistors. If the string is substantially above zero due to solar heating heat will conduct down the string and there may be small localised melt at entry to the ice. The water would have a lower albedo and would compound the problem of solar heating. It would also lower the level at which heat flux down the thermistor starts to penetrate the temperature gradient within the ice.

It's tricky, but on the face of it I am not convinced about the new design - its larger surface area suggests more potential for warming and heat flux into the fitting hole than a thin string of thermistors.

Now I am reminded about why I looked at the data from these buoys about two years ago and decided I wasn't convinced it was very useful to me.

[Ostepop1000]

A general remark: where denizens of WUWT would like Arctic ice to grow, to prove their theory that human-induced warming has little impact on temperature and thereby on the melting of Arcic ice, I find the opposite on this forum:

Here on this forum, people are cheering on the ice to melt as soon as possible. Looking for evidence of melting, hoping for the weather to be conducive to melting, hoping for an ice-free Arctic to make headlines across the world.

Both groups are blinkered, one-eyed, two-tongued, deaf by choice, unscientific cheerleaders, disconnected from the reality that normal people inhabit.

Most of the warming we have seen in normal times is probably natural. Even the IPCC admits it, finally.

And when the world community asks the question: "How much warming can we expect from a doubling of CO2 in the atmosphere?"

The IPCC answers: "we have no idea. We used to think it was around 3 degrees. Recent studies now indicate it might be much less, but there are scientific differences, so we now refuse to give you a number. It would be a lot lower than last time, so you might use it against us and against our cause, so we prefer not to give you that number."

Good stuff, IPCC.

Stabding up for science and rationa.ity in the face of politics and the irrationaity of emotions!

[D]

Ugh, we just got trolled.

The IPCC answers: "we have no idea. We used to think it was around 3 degrees. Recent studies now indicate it might be much less, but there are scientific differences, so we now refuse to give you a number. It would be a lot lower than last time, so you might use it against us and against our cause, so we prefer not to give you that number."

Good stuff, IPCC.

Stabding up for science and rationa.ity in the face of politics and the irrationaity of emotions!

RE troll: There was no pause. There is absolutely no statistical basis for any claims of a slowdown in global warming. Grant Foster, statistician, analyzed the temperature data in detail and it didn't even come close to being anything but natural variability on a long-term linear increase in temperature.

https://tamino.wordpress.com/2015/04/30/slowdown-skeptic/

RE temperatures below the ice: Don't forget that once the snow is melted that light penetrates into the upper layer of water below the ice, heating it.

[Kevin O'Neill]

Osteopop - The IPCC does not say they have no idea how much warming there will be due to a doubling of CO2. The IPCC Fifth Assessment Report stated: Equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C (high confidence), extremely unlikely less than 1°C (high confidence), and very unlikely greater than 6°C (medium confidence).

"Most of the warming we have seen in normal times is probably natural. Even the IPCC admits it, finally." I call Bulls...t. Please provide a citation.

Is it possible for you to post without spreading incorrect or misleading information?

[Kevin O'Neill]

Osteopop wrote: "Most of the warming we have seen in normal times is probably natural. Even the IPCC admits it, finally."

I call bullsh...t. Here's what the IPCC *actually* says:

"It is extremely likely that more than half of the observed increase in global average surface temperature from 1951 to 2010 was caused by the anthropogenic increase in greenhouse gas concentrations and other anthropogenic forcings together. The best estimate of the human-induced contribution to warming is similar to the observed warming over this period."

In IPCC parlance, 'extremely likely' means with 95% confidence. Note this is all anthropogenic - GHG forcing alone would be *higher* because currently they are offset by aerosols. And the final sentence pretty much sums it up; the human-induced contribution is similar (equal) to the observed warming. I.e., all of the warming is anthropogenic.

Osteopop, as always, is full of it.

[Ostepop1000]

Kevin O'Neill:

Your qute:

"The IPCC Fifth Assessment Report stated: Equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C (high confidence), extremely unlikely less than 1°C (high confidence), and very unlikely greater than 6°C (medium confidence)."

Show us the proof.

[Ostepop1000]

Kevin O'Neill:

Your quote:

"The IPCC Fifth Assessment Report stated:

Equilibrium climate sensitivity is likely in the range 1.5°C to 4.5°C (high confidence),

extremely unlikely less than 1°C (high confidence),

and very unlikely greater than 6°C (medium confidence)."

Lat's just agree that we know very little.

Almost nothing.

OK?

[Ostepop1000]

We know almost nothing.

Agree or disagree.

That's what the IPCC says.

[Ostepop1000]

[snip, please write in English, and stop trolling in any language, thanks; Neven]

[D]

Speak for yourself. You know almost nothing, troll.