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Robert S

Great work, Neven!


This is well worth waiting for. Thanks, Neven.

John Christensen

Great update as always, thank you Neven!

Regarding DMI 80N temp: From the ecmwf forecast it seems like the anti-cyclone on the Siberian side will deepen and move towards the geographic Pole.
This seems to push winds in a southerly direction in the Fram, and I would therefore think the 80N temp will drop to the longterm average in about 4-6 days.
Is that normal: Not really, since an ideal cold weather state like that in the past would have been colder than the average..


There is of course the real explanation of what is going on, always difficult to grasp by many, unless you live it, live from the Arctic, and it seems a "coup d'etat" by where ever the evolving snow falls most. Stating where the pressure cells are is so 1980's, a primitive pre satellite days attempt to explain things ....


I suspect the complexity of sea ice needs be explained by the weather above, and the sea water below. But it is always not what it appears to be.


John, have you seen how far it's gone up since then? Wayne is alluding to how sea ice can only be explained by the sea below and the air above.... I bet ya he means MYI!!

John Christensen


Yes, DMI 80N did go up and is now coming down again. It will continue getting colder until tomorrow or early Tuesday as mentioned above, but the core of the cold will be slightly off the Pole towards Beaufort, and it is unlikely for the 80N temp to reach down to longterm average.

John Christensen

As mentioned Thursday the anti-cyclone has now centered around the Pole, which - unsurprisingly - has cooled down the central polar area.
I would note that by this primitive 1980's pre-satellite approach we could observe from last week, how the temperatures would change, and that the cold spots near the Pole and in the Beaufort are indeed colder than the surface temps in the CAA.

And let me then continue the old-fashioned forecasting by mentioning that the high now seems to move back to the Siberian side - which will make it really cold there, while temps in the CAA will continue rising in the next few days.

So will the CAA this winter be the dominant Polar cold center? Not sure, it certainly could, but when a high broadens into Siberia as will now happen, then it just might influence what happens next.


In light of the content of some of my comments under the previous article, I’m projecting a significant deceleration in the decline of Arctic sea ice volume, if that hasn’t already happened. This includes the case in which the decline in Arctic sea ice area and the decline in average Arctic sea ice thickness continue in line with their respective current best-fit linear trends. Arctic Sea Ice Blog commenter Chris Reynolds has projected a future deceleration in the decline of average Arctic sea ice thickness. That should result in further or greater deceleration in the decline of Arctic sea ice volume than if the decline of average Arctic sea ice thickness were to not decelerate.

Also, I’m suggesting that, while Arctic sea ice volume is a good measure of how much Arctic sea ice remains, it is not currently good for projecting when the Arctic might be virtually free of sea ice. Maybe Arctic sea ice area or average thickness of Arctic sea ice is good for that.

Clueless FM

[edit: Nice self-advertising, Vid, but I'm not biting; N.]


I didn't think it was lowest volume!

Clueless FM

Deleting the biggest sea ice news of the year doesn't make us NOT lowest ever, fascist.

Rob Dekker

DCS said :

In light of the content of some of my comments under the previous article, I’m projecting a significant deceleration in the decline of Arctic sea ice volume, if that hasn’t already happened.

You seem to advertise the theory that summer heat melts only 'area', not 'volume'.
Do you have any evidence that that "already happened" ?

Rob Dekker

The question is especially important, since so far the statistical evidence suggests that 'volume' loss is still accelerating :


John Christensen


Yes, with all trends going in the same direction it certainly seems like we are headed for a major crash in the next few years, or the trend will need a significant shift.

John Christensen

Separately, is that Viddaloo above with the name-calling?


Yes, ignore him (here). You can go to his YouTube channel if you're interested in what he's got to say.

John Christensen

No need, good to see you keep the ship straight Neven, thanks.


Rob Dekker,

I'm not "advertising" that, not remotely close.


Rob Dekker,

I don't know whether or not the decline in Arctic sea ice volume has already decelerated.


Rob Dekker,

Regarding your statement that those graphs show that Arctic sea ice volume is still accelerating, note that some of those curves (such as the exponential ones) FORCE a continued acceleration, and they show a best fit under that assumption. The Gompertz curve forces an eventual deceleration, and that graph shows it happening about now. Such graphs are not a proper way to do a change-point analysis.


The hypothesis that Arctic sea ice volume should decline linearly is based on the idea that, as the Arctic gains heat, the added heat should go into reducing Arctic sea ice volume at a constant rate. However, I believe that that is unrealistic because the rate of transfer of heat from warmer ocean water is proportional to the area of the ice that is exposed to the water and the rate of absorption of heat from sunlight by the ice is proportional to the area of the ice. As Arctic sea ice area declines, so should the total rate of absorption of heat by the ice (not per unit of area). Granted, reduced sea ice area results in a lower albedo, which can increase the rate of warming of the ocean by sunlight, but reduced sea ice area and thinner ice can also result in greater heat loss from the ocean during darkness as has been mentioned here many times. Put another way, with reduced sea ice area, a given reduction in average thickness acts on less area, resulting in less volume loss. *(see below)

Also, if Arctic sea ice volume were to decline linearly then the decline in Arctic sea ice extent should accelerate, as the 1979-2016 linear trend in extent projects to 0 at a much later year than the year at which the 1979-2016 linear trend in volume projects to 0. Instead, this graph from the Tamino blog


shows a recent deceleration in the decline of annual average Arctic sea ice extent.

As I stated under the previous blog article, a linear decline in Arctic sea ice area together with a linear decline in average Arctic sea ice thickness corresponds to a decelerating decline in Arctic sea ice volume, and even an accelerating decline in each of the former two can correspond to a decelerating decline in the latter.

Noting that volume is 3-dimensional, area is 2-dimensional, and thickness is 1-dimensional, and then comparing how y = x^3, y = x^2, and y = x approach 0 as x approaches 0, I think that it shouldn’t be a surprise if the decline in Arctic sea ice volume decelerates as it approaches 0, as y = x^3 approaches 0 more quickly than each of y = x and y = x^2 until y gets “close” to 0, after which y = x^3 approaches 0 more slowly than each of the other two.

My projection of a deceleration in the decline of Arctic sea ice volume, if it hasn’t already happened, is based in part on the above arguments.

Also, I’m expecting an increased volatility of the annual minima, if that hasn’t already happened, but that’s another topic.

* If future decline in Arctic sea ice volume were driven almost entirely by a decline in average thickness (with little contribution by a decline in area) then area could ostensibly stay almost constant for a duration. However, it seems unlikely that the linear trend in volume decline could be maintained this way, as a significant part of the past volume decline has been due to area decline. There would need to be an initial acceleration in the decline in average thickness (to compensate for a lack of decline in area), which seems unlikely, and then that accelerated rate of decline in average thickness would need to be maintained. In reality, there should be a negative feedback in the decline of average thickness, due to thinner ice that can better conduct heat loss in winter. It is far-fetched that average thickness would decline much without much decline in area anyways, as thinning ice should melt out in some areas. In any event, there isn’t much indication that area will remain close to constant in the foreseeable future.

John Christensen

Hi D_C_S,

Not sure I grasped the entire argumentation, but I certainly like the idea of the deceleration of sea ice volume decline.

The main arguments for future change in sea ice volume that I recognize, are:

1. Axial tilt: Luckily the axial tilt does not change much, and should help dampening any tendency of accelerating warming, simply as heat will continue escaping the polar area during the Arctic winter

2. Radiative forcing: More CO2 will increase radiative forcing, but it seems like the forcing will not increase as much as the increase in CO2.

3. Sea ice cover: Finally, the reduction in sea ice cover will increase heat influx from the atmosphere, which will tend to accelerate sea ice volume reduction.

I have not considered other factors such as melting tundra, etc., just to focus on the main elements.

The live experiment we are witnessing is how this will play out; will the combined impact be an accelerating volume loss (As trends indicate), or will we see a drawn out decline, as the seasonal changes will continue building sea ice during winter as happens in southerly areas such as the Gulf of Bothnia.


Here is my proof from under the previous blog article that if Arctic sea ice area and average Arctic sea ice thickness are each declining and neither of those declines is accelerating (neither is speeding up its declines) then the decline in Arctic sea ice volume must be decelerating (slowing its decline):

Proof: Assume that A(t) and T(t) are each continuous and twice differentiable. Note that V = A T. Then V'(t) = A(t) T'(t) + A'(t) T(t), and V''(t) = A(t) T''(t) + 2 A'(t) T'(t) + A''(t) T(t). Assume that A(t) > 0, A'(t) < 0, A''(t) ≥ 0, T(t) > 0, T'(t) < 0, and T''(t) ≥ 0. Then A(t) T''(t) ≥ 0, 2 A'(t) T'(t) > 0, and A''(t) T(t) ≥ 0. It follows that V''(t) > 0 and that the decline in V is decelerating.

Here is my proof from under the previous blog article that even if Arctic sea ice area and average Arctic sea ice thickness are each declining at an accelerating rate (speeding up their declines) then the decline in Arctic sea ice volume could be decelerating (slowing its decline):

Proof: Here is a hypothetical scenario to demonstrate that the decline in volume can decelerate as the decline in area accelerates and the decline in average thickness accelerates.


(1 Mm^2 = 1 million km^2)

Area in Year 0: 12 Mm^2
Area in Year 10: 8 Mm^2
Area in Year 20: 3 Mm^2

Decline in Area From Year 0 to Year 10: 4 Mm^2
Decline in Area From Year 10 to Year 20: 5 Mm^2

The decline in area accelerated.


Average Thickness in Year 0: 3.5 m
Average Thickness in Year 10: 2.5 m
Average Thickness in Year 20: 1 m

Decline in Average Thickness From Year 0 to Year 10: 1 m
Decline in Average Thickness From Year 10 to Year 20: 1.5 m

The decline in average thickness accelerated.


Volume = Area X Average Thickness

Volume in Year 0 = 12 Mm^2 X 3.5 m = 42 thousand km^3
Volume in Year 10 = 8 Mm^2 X 2.5 m = 20 thousand km^3
Volume in Year 20 = 3 Mm^2 X 1 m = 3 thousand km^3

Decline in Volume From Year 0 to Year 10: 22 thousand km^3
Decline in Volume From Year 10 to Year 20: 17 thousand km^3

The decline in volume decelerated.

Rob Dekker

DCS, I hope you are right.


DCS, you said:

Also, I’m expecting an increased volatility of the annual minima, if that hasn’t already happened, ...

I think you will find "Jim" from "The Great White Con" Blog may like to talk to you about that exact phenomena/observation as he has pointed out on his blog that there seems to be different shaped minima curves occurring over the last few years....

You might find he has some interesting things to say to you about exactly your point of expectation.

John Christensen

Hi wayne,

You wrote on your blog a couple of weeks ago, Nov. 17:

"New state of the art refraction technique confirms Canadian Archipelago atmosphere set to dominate Global Circulation."

And concluded:

"At present, 2017-18 seems to tend going towards a very warm Euro-Asian Arctic winter, while CAA is coldest, we observe if the cut off of snow supplied from the North Atlantic by way of the the North Pole continues, if so, permafrost will freeze hard, sea ice will thicken more, a very cold CAA CTNP will dominate weather as is for quite some time in the foreseeable future."

Two weeks later the CAA is unusually warm with areas as much as 15C or more above average temperatures, while central/eastern Siberia is considerably colder than normal:


Now, if you hadn't used the condescending tone above I would have ignored this - as we all fail in our attempts to understand weather - but would you like to comment on how your approach has worked?

John Christensen

Arctic weather forecast for the coming week with impact on sea ice:

The current low in the CAA will fade away, but then is set to reappear in 4-6 days, as moisture moves north across the US and fails to pass south of the Greenland high, which continues to block the moisture on its western side.

With both the Greenland and Siberian highs seemingly fixed, the three lows (CAA, Barents Sea, and Bering Sea, and the high hovering over the Arctic sea ice (Semi-connected to the Siberian high) will remain.

Central area of the ice will therefore be cold with the Beaufort Gyre picking up speed and further cooling down Hudson Bay, Sea of Okhotsk, while ice accumulation in Barents, Kara, Baffin, Bering will remain weak.


In Wayne's defence I wouldn't say he was using a condescending tone: I think he is simply being forthright in his opinions and actually enjoys the learning he gets from perhaps being wrong at times and so pursuing the mission!


I looked at your link and there certainly seems to be some plus 15 degree Celsius anomalies as you say in the CAA!


(I also note that dmi temps for Saturday, Dec 2, went up!)



"Two weeks later the CAA is unusually warm with areas as much as 15C or more above average temperatures, while central/eastern Siberia is considerably colder than normal:"

My oh my, as if I did not notice:


John you have a continuous habit of jumping into conclusions without reasoning your assertions. The greatest cooling zone of the world "attracted" a strong Low to remain fascinatingly still causing warm air
advection giving temperature records. This is weather John ! You
assume wrong , at least you are consistent.

Now that this situation has more or less vanished, the cooling over the CAA is returning strong and is just about to dominate again. Luckily the mega blizzard (a weather event) didn't appear to last the whole winter.

I find your penchant to be annoying very amusing!!! And especially revealing. Besides there are other more serious things to worry about:



My point about "pressure system" comments stands. It is a very old way of expressing an obvious image or prognosis, without explaining the origins of the High's or Lows, they are just there, as a matter of fact, a bland assessment.


Why is there a High over the Arctic Ocean now? Aside from just stating that there is one, it is because there are two very cold atmospheric cells dominated by land zones, mainly because they have more snow (or Glaciers) on the ground. But if we don't know where the snow is, we are stuck to express in bland terms, the ice moves out more because there is a High over the Arctic Ocean, the ice is kept in because there is a Low etc.

What we fail to figure out, as the volume of sea ice goes towards a vanishing point, Global Circulation changes from very basic geophysical transformations. Namely, with warming oceans twinned with lesser sea ice, we see smaller cold cells, instead of a huge big one, which in turn gives the great jet stream undulations which cause anomalous weather events. Such as the mega blizzard just past.

As John would describe:

"With both the Greenland and Siberian highs seemingly fixed, the three lows (CAA, Barents Sea, and Bering Sea, and the high hovering over the Arctic sea ice (Semi-connected to the Siberian high) will remain."

Sigh, terrible description. Greenland most always has a High (it is
at very high altitude and the calculation to sea level pressure makes it often so). "Seemingly fixed" old way of doing things, why is the one over the Arctic Ocean fixed?


Thanks Another Journey

It is good to be wrong only we admit we are. It is a way of learning by observing whether or not an hypothesis is correct. As far as my latest projections are concerned, when forecasting there should be always a disclaimer in fine print:

"wait for the projected time period ends before making a comment" :)

As far as sea ice is concerned the warmer weather over it in tandem with a frequent persistent presence of a High (which should be a cold Anticyclone) should raise alarm bells. But as we were tagged by the oil funded loud mouths, we are definitely not alarmists :)


DCS, whilst the logic of losing a greater amount, of less ice, means that less volume is lost overall; there are a few gotcha's in that calculation when it comes to the reality of sea ice loss.

First and foremost is that the amount of ice lost tends to be correlated to the amount of energy entering into the system. Given weather and other mechanisms throw a spanner in the works, it is still a case that measured w/m^2 input gives us x% of ice loss.

If we have less ice to lose, then the ice is not doing its job of offsetting the input of energy. In that case, in a 2007/12 scenario, the ocean and land of the Arctic is going to take up the offset with heat absorption.

Whilst more sea is roughly equivalent to more heat transferred to the atmosphere at the onset of winter, the rapid onset of Arctic winter can cap the heat transfer and retain a portion of that heat.

Regardless, instead of reflecting and radiating out to space or being used to transition ice to water, the heat will be absorbed and some will remain in the system.

You mentioned that in terms of albedo but not in the sheer amount of fusion energy required to change ice to water 333kj per kg, without changing the temp by 1k. The less ice we melt to water, the less fusion energy we take up, over and above all the other energy to move it from -5 or less.

Essentially we have a smaller aircon so we get hotter. How this balances with having a smaller blanket (initially), in winter is an interesting point, but the other point is that this heat, initially, transfers to the local atmosphere. Inhibiting further ice generation until it can be moved away by the weather systems.

The other point you didn't mention is this.

Right now the thermal inertia of the current volume of ice is greater than the thermal inertia of any single melting season. Thus it is, essentially, impossible to lose the entire pack in one melting season.

However, as the average thickness of the ice reduces towards 1m and the area of that ice declines, we reach the state where the thermal inertia of the ice becomes less than a single exceptional melting season. Which puts the Arctic into a shooting gallery for any exceptional melting season.

So whilst the math and the stats are valid, in terms of reduction; so is the fact that the entire system can flip to another state right in front of our eyes.


Dmi temps for Sunday, December 3, are up again!

What in the world are we giving our kids for Christmas??



I was already aware of considerations of that nature before I made my projection.

John Christensen


Regarding the DMI 80N temp, which I assume you are looking at:

This measure is calculated as the average temperature for each degree of latitude between 80N and 90N. Consequently, the average temp of the 80N latitude has the same weight as the 89N latitude, although the latter covers only a tiny geographical area.

The DMI 80N measure is therefore extremely sensitive to the temperature at the geographic Pole and not the CAB or the Arctic.

DMI 80N temp is then useful only to compare across years and seasons, but is not providing a meaningful measure of the Arctic temperature.

I referenced DMI 80N a few weeks ago since an anti-cyclone was moving to the geographic Pole, which therefore more significantly impacts this measure.

Right now the anti-cyclone is closer to the Siberian side, so the cold is moved to the lower latitudes on this side, while the highest latitudes are relatively warmer:



John, so is there a better indicator of arctic temperature?



I can’t seem to copy the exact image but in the second set of images in this article, entitled “Percent of average precipitation”, Mexico seems well dried and I have heard that started a number of decades ago but I can’t source that information.

Further, it looks (to me) like the drying of Mexico started (when I’m not quite sure) and this has simply spread North and so I suppose will continue to do so!

I think I have also read that it is the Western side of continents, and so the Eastern side of ocean gyres, that generate this behaviour.

Do I have the right to read that from that particular graphic?

Clueless FM

Arctic sea ice volume for January-November was lowest ever at 12.9 k km³. 2017 is bound to go lowest on record for the full year at 12.7-12.9 k. Previous record low 2012 ended at 13.5 k km³.



There is a great deal of resilience in localized deep frozen atmospheric areas, namely the CAA is back cold, despite a massive warm temperatures record shattering event. A study of how long this warming remains turns out to demonstrate that warm air advection events may seem big, but huge cold cells are deep rooted upwards and on the ground, and have persistence.


Kevin McKinney

John, I don't think that you're correct about the DMI-80 methodology. At least, what it says on their page is this:

The daily mean temperature of the Arctic area north of the 80th northern parallel is estimated from the average of the 00z and 12z analysis for all model grid points inside that area.

Since the number of model grid points per latitudinal band is not constant, the issue you identify should not arise. Here's what they have to say about the grid structure:


"The standard Gaussian grid has the disadvantage that the east-west distance between the grid points decreases polewards. To avoid some numerical problems around the poles and to save computing time, a reduced Gaussian grid was introduced in 1991, which reduces the number of grid points along the shorter latitude lines near the poles, so as to keep the east-west separation between points on different latitudes almost constant."

John Christensen

Hi Kevin,

Yes, but..

DMI has this to say about their 80N temp:

"Plus 80N Temperatures - explanation.

The temperature graphs are made from numerical weather prediction (NWP) "analysis" data. Analyses are the model fields used to start NWP models. They represent the statistically most likely state of the atmosphere, given the information available to make the analysis. Since the data are gridded, it is straight forward to deduce the average temperature North of 80 degree North.
However, since the model is gridded in a regular 0.5 degree grid, the mean temperature values are strongly biased towards the temperature in the most northern part of the Arctic!
Therefore, do NOT use this measure as an actual physical mean temperature of the arctic. The 'plus 80 North mean temperature' graphs can be used for comparing one year to an other."



Fair enough John, but complex systems can only be measured by indicators: so the question simply becomes, “Is there a better indicator?”

The exact numbers don’t really matter that much: it’s all about the relationship!

Hence graphical aids!



This article says sea temperatures pick up trends in global warming faster than other methods of measurement!



NSIDC also has a nice piece on “Open water in the Chukchi Sea”

John Christensen


You wrote Nov. 17:

"a very cold CAA CTNP will dominate weather as is for quite some time in the foreseeable future."

I commented on Dec. 2, but that was too early, as you said:

"wait for the projected time period ends before making a comment"

However, in the forecast reaching mid-December I still see the circulation dominated with the Siberian high semi-connected with the high between the Pole and Laptev, so is the foreseeable currently ongoing or have we perhaps not reached it yet?? ;-)

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