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Thank you for putting this up so quickly Neven.
Please correct a typo (29,900 should be 22,900).

Cheers P

John Christensen

Yes, thanks for a quick update on PIOMAS Neven!

PIOMAS average thickness:

The average thickness is calculated for the PIOMAS domain by only including locations where ice is thicker than .15 m (i.e. by extent)

Since ice area has declined less than ice extent in April, the average thickness has increased more with the PIOMAS calculation rather than with your calculation using the area numbers.

The Polar Science Center thickness graph looks a lot different this month, with 2014 jutting out a lot more above the other post-2010 years. It has something to do with how they calculate average thickness, but I forgot the details:

The PSC graph shows average grid cell thickness. That is they add up all grid cell thickness measures and divide that by the number of grid cells.

So it is not a true area-averaged number: the smaller grid cells have a relative overweight. Those small grid cells are near the grid pole: in the northern half of Greenland. This fits nicely with observations that more thick ice near Greenland and Canadian Archipelago is found this year.

We will be able to check this when/if the gridded daily data from April will become available as well.


Nature Paper: Half Of Arctic Warming Due To Pacific


Andy Lee Robinson

Food for thought - April's average volume of 22,931km³ is a sphere 35km in diameter.
Therefore all Arctic sea ice could fit on a city the size of London.

Compared to the Earth, that's like a hailstone to an elephant! Sobering, considering its influence.

The Arctic Death Spiral still retains its distinctive shape as if last year's trend hiccup never happened.

No recovery in sight.

Shared Humanity


Nature Paper: Half Of Arctic Warming Due To Pacific


This statement in their paper and their conclusion that 50% of Arctic Warming is due to Pacific tropical warming seems contradictory.

"It remains to be seen to what extent the Pacific temperatures may themselves be responding to human effects on the climate system, they report."


Stronger than normal tropical convection over Indonesia over the past 15 years has had many effects on the climate system including increased storage of heat in the oceans. That Nature paper is interesting but I think that no one should jump to the conclusion that the strengthened convection in the Pacific is caused by natural variability. Natural variability is likely a factor but decreasing production of Antarctic bottom water is likely to be a factor as well.

Paleoclimate studies have shown oscillations between Arctic and Antarctic warming. When the production of Antarctic bottom water declines, less oceanic heat moves towards Antarctica and the ocean surface around Antarctica cools. That's what's happening now. At first it may seem counterintuitive, but this is caused by global warming.

What's happening is that warm water at a depth of 100m to 300m is melting Antarctic glaciers from below, freshening the surface waters. The freshened surface waters stop large scale mixing and deep convection. Thus, Antarctic Deep water formation has ground to a halt in the Weddel Sea and deepwater formation around Antarctica has declined about 20%, if I remember correctly.

The net result is more warm water in the southern hemisphere's tropics and subtropics and cooler waters around Antarctica. The increased thermal gradient and warmer water in the tropics intensifies the tropical convection and the Walker and Hadley cells.

Thus anthropogenic climate change may have contributed to the intensified Indonesia convection that contributed to the warming in Greenland. The earth's climate system is connected in complicated ways. Natural variability is always a factor in weather and climate but it isn't a catch all for factors we have failed to analyze.

-FishOutofWater aka George


>"Looking at the data I see that modelled volume reached 23,104 km3 on April 15th, which is slightly more than the 292,900 mentioned. Maybe the folks over at the PSC calculated the max differently."

The average of the 30 days in April comes to 22.931 so I suspect this is a rounded monthly average rather than a single day maximum. Probably best not to expect too much accuracy at one day level so I would expect scientists to look more at monthly average than a one day max.

Whether you use a monthly average or single day this is second lowest, above 2011 by about 0.42 or 0.427. So little difference.

Shape of curve in April this year is unusually flat ending month at 3rd lowest. Not really sure why this is. Any ideas?

Please correct a typo (29,900 should be 22,900).

Indeed. Merci pour catcher, as they say in French.

And thanks to John and Wipneus for re-explaining the discrepancy between PICT and PIOMAS thickness. I'll ask again next year. ;-)

The average of the 30 days in April comes to 22.931 so I suspect this is a rounded monthly average rather than a single day maximum.

I calculated that average, but somehow got something else (it was early). This explains it. Thanks, crandles.


Re: Ding paper: It's interesting that fixing tropical SST to the observed is sufficient to set up the observed blocking pattern. On the other hand, the stratosphere tends to have the same number of wiggles (different in summer and winter), and it seems probable that fixing any one region as either very hot or very cold would set up a standing wave which looks very much like observed pattern.

Did they do a sanity check? The sanity check would be whether the modeled heat flux is vaguely reasonable. We know that the models get the albedo of the Arctic in general and of Greenland in badly wrong, which likely sets up a blocking pattern in Greenland in reality but not in their models. If the blocking is really due to the models getting the tropical SST wrong, what is their explanation of why the models fail here?

If only a few of your ensemble members match reality, it's a pretty good sign that reality is an outlier. On the other hand if none of them do, it's a pretty good sign that your model is broken. There just isn't much of a observed correlation between NAO and ENSO or PDO, and claims to the contrary will have to explain why little correlation is observed in reality.

The NAO-/AMO+/Greenland blocking pattern is known to be already significantly due to natural variability, so the significant natural variability conclusion is likely correct, but I haven't heard where they've justified the conclusion of tropical SST causality.

@George: Generally the top of warmer water is around 125m to 500m, so the depth you're talking about is usually cold, but multiple grounded basins have sills down to nearly 1000m.

Pressure gradients will always stay small near the bottom because there's friction. If, as seems probable, the deep Southern Hemisphere oceans keep absorbing heat, this will translate to surface height changes which will start to have huge effects on ocean currents, probably pouring heat across the Equator as net northward surface currents. This already happens by the default climatology and is increasing slightly. The density-change driven geostrophic current climate change effect is still fairly small, but the deep oceans have really barely begun to respond.

Compare the much greater temperature increase of the Northern Hemisphere with the much greater surface height increase of the Southern Hemisphere. Some asymmetry is predicted by current models, but this degree is really problematic. They don't do well on paleoclimate hemispheric temperature differences either.



Reportingclimatescience reports on a paper that shows that RISING tropical Pacific SSTs are exacerbating Greenland melt; and finds an expert from AWI who explains that it's due to FALLING tropical Pacific SSTs.

Is the tropical Pacific warming or cooling?

(In anticipation of the Californian drought having an adverse effect on the global price of wine, I have taken early precautionary action, and am quite unable to answer this question for myself. Any elucidation would be gratefully received;),



@idunno: The trend since 1998 is cool in the eastern tropical Pacific and warm in western tropical Pacific. You're right, they don't do a terribly good job of explaining that.

The opposite should be the case for the next year or so, which should help with the drought.


Sentinel satellite spies ice cap speed-up



Here's my write up of the recent research on the cessation of the Weddell sea overturning.


It links to an earlier story I wrote about the discovery reported about a year ago on the formation of a low salinity layer on the western side of the Antarctic Peninsula that is impeding overturning there. Overall, Antarctic deep water production has dropped at least 20%.

Last winter strong subsidence from the stratosphere over the south pole led to stronger than normal offshore winds around Antarctica. The combination of these winds and less overturning caused sea ice around Antarctica to expand to near record levels (short record).

The Antarctic circumpolar current and the southern polar jet have tightened around Antarctica. This is coupled with an increase in intensity of the trade winds which have cooled the equatorial eastern Pacific and deepened the warm pool in the western tropical Pacific.

And that ties in with the article in Nature which we are discussing.


Thanks for the resumé, Neven.

I’d like to weigh in on PIOMAS April ’14 too with some NCEP/NCAR comparisons, but find trouble with my system/programs.
So let me just say I’m a bit surprised to see the ‘flat’ line on volume.

Especially the ‘second bump’ near the end of the month, whereas the lines for ’12 and ’13 started moving down. I see not much on the 1000Mb temperature reanalysis that could easily correspond with these differences.

Bottom line is the explanation on the PIOMAS site about uncertainty margins. The same goes for the temp differences,nothing obvious.
So a couple of hundred km3’s are probably not worth much attention when this season gets further down the line.

BTW read Bernice’s blog post (I think 7/5) on Expedition Hope, a vivid description of the actual state of the MYI North of Ellesmere!

John Christensen

Regarding the 'second bump' in volume by end of April, there could possibly have been new ice build-up in the western part of Hudson Bay, as winds had compacted ice near the eastern coast and temps remained low.

Also in Laptev, temps have come down again after ice being moved north, so some new ice should have formed.

Just not sure this would justify the bump..

Colorado Bob

Posted by: Boa05att
Sentinel satellite spies ice cap speed-up

"We've observed Austfonna with various satellite radar datasets over the past 20 years, and it hasn't done very much," explained Prof Andy Shepherd from Leeds University, UK.
"But we've now looked at it again with the new Sentienl-1a spacecraft, and it's clear it has speeded up quite considerably in the last two or three years. It is now flowing at least 10 times faster than previously measured."


Colorado, hi,
For those interested, Austfonna Jokull is on Nordaustlandet, the remote NE island of Svalbard.

Bill Fothergill

@ Neven

It will be interesting to see if your (possibly tongue in cheek???) hint about perhaps getting access to near real time data pertaining to surface melt ponds comes to anything. Any news on that front yet Neven?

Given the wildly divergent outcomes of the last two years, it would be a brave (or foolhardy) person who would attempt a confident prediction this early as to how the 2014 melt season is going to pan out.

Having said that, I will, of course, do the opposite and attempt one prediction. Last year, a certain Lawrence Solomon treated us to his words of wisdom regarding the non existent decline in Arctic sea ice. For about 5 weeks - starting mid April - last year's sea ice extent rose marginally above the equivalent 1989 numbers. As far as Mr Solomon was concerned, this presaged a recovery from a decline which, according to him, didn't even exist in the first place.

(There should be a portmanteau location for all that sort of absolute crud. A suitable name might be "We_grasp_any_straw.com".)

Well blow me, if it didn't happen again! According to the NSIDC figures, this year's extent was once more above 1989's numbers from the 28th of April to the 3rd of May (inc).

1989 was a real outlier for May, and is still 5th lowest on the NSIDC figures. My reasonably confident prediction is that it won't be 5th lowest by the end of the month. Although this year is only slightly ahead as at the 8th (13.256 Vs 13.101), 1989 experienced the lowest drop for the remainder of the month in the NSIDC dataset.

This can be easily seen by using the Charctic tool on the NSIDC site. (Hint: Do a "Hide all" and then reselect 1989 and 2014.)

Will May 2014 be lower than 5th? Dunno.

Colorado Bob

This Weekend Watch Schwarzenegger Fight Wildfires, Or GOP Pol Make On-Air Climate Science Conversion

James Cameron’s acclaimed docu-series, “Years of Living Dangerously” is essentially the U.S. National Climate Assessment in living color. Now, Showtime is making “Years” available for free this weekend.
I’ve heard plenty of concerns from folks who watched the first episode online but have been wondering what to do since you don’t subscribe to Showtime. You haven’t been able to see Episode 2, in which Harrison Ford actually gets action from corporations and even the Indonesian government on the illegal deforestation seen in Episode 1. Nor have you seen former California governor Arnold Schwarzenegger join a Colorado Hotshots wildfire fighting team and learn about how climate change is making wildfires worse. This is an especially timely story given the record drought and early start to the wildfire season in California this year.
The good news is that this weekend — May 9-11 — Showtime is making all its programming, including “Years of Living Dangerously,” available for free to 74 million homes that get cable, which is to say most of the country. And most of those homes will be able to watch all of the first four episodes.


Any news on that front yet Neven?

No real news there, Bill. We'll have to wait and see.

Colorado Bob

I spent the most of the day trying to remember something that when with this news about Svalbard......

Constant Arctic Heatwave Sends World’s Largest Ice Cap Hurtling Seaward

Svalbard. Until lately, a little-known locale situated between the previously frigid extreme North Atlantic and the Arctic Ocean about 500 miles east of Greenland. Typically a frozen island Archipelago, this pristine and sparsely inhabited redoubt has, over the past few years been ground zero for the assaults of an ongoing and extreme polar heat amplification.


Then I remembered this :

Northeast Greenland ice loss accelerating, researchers say
March 16, 2014
Ohio State University
The last remaining stable portion of the Greenland ice sheet is stable no more, an international team of scientists has discovered. The finding will likely boost estimates of expected global sea level rise in the future. The new result focuses on ice loss due to a major retreat of an outlet glacier connected to a long “river” of ice — known as an ice stream — that drains ice from the interior of the ice sheet. The Zachariae ice stream retreated about 20 kilometers (12.4 miles) over the last decade, the researchers concluded. For comparison, one of the fastest moving glaciers, the Jakobshavn ice stream in southwest Greenland, has retreated 35 kilometers (21.7 miles) over the last 150 years.


Colorado Bob

Sorry, I have spent nearly 65 years writing {when), when I wanted to write went .

Bill Fothergill

@ Bob

Bloody useless old fogey.

I, on the other hand, have spent a mere 64 years randomly duplicating the the definite article.

Bill the the frog


NSIDC's April review is out, featuring the Nature melt ponds paper:

'The size and number of melt ponds on sea ice are in part governed by the sea ice topography. First-year sea ice is smoother than multiyear ice, and the melt ponds tend to be shallower and more spread out over the first-year ice. While the melt pond fraction in May makes up about 1% of the total summer melt pond fraction, the shift to a predominantly first-year ice pack has helped to increase the number of melt ponds in spring and provides useful input into predictions for September sea ice extent.'


Regarding Bill's comment at 22:02, Lawrence Solomon writes for one of Canada's two national newspapers. That paper has four or five columnists who consistently attack AGW and have for years. No idea why the paper has such an unbalanced editorial policy unless it's advertising money from oil companies or senior management bias. FWIW all of the columnists are well on in years.

Bill Fothergill

@ Magma

Mr Solomon first appeared on my radar about 5 years ago after he had collated a series of "it ain't happening/ it ain't us/ it ain't bad" bollox - sorry, I meant articles - into a book called "The Deniers".

Sadly, the term "denier" has inescapable overtones following the Holocaust. However, if pronounced slightly differently it sums things up rather well. The denier is a unit of density measurement employed in the textile industry and effectively describes how full of holes something is.

In April last year, in a totally successful attempt to wind me up, one of my old chums from university days showed me the latest egregiously bad offering from Mr Solomon.

As a form of catharsis, I documented the voluminous errors in Mr Solomon's article, and Neven was kind enough to allow me to post it here.

Yesterday, whilst playing the "guess the monthly average Arctic extent after the first 7 or 8 days" game, I happened to notice that 2014 was extremely likely to bump 1989 out of its current position as 5th lowest average for the month of May. This triggered the appropriate neurons (still a few left) and reminded me about Mr Solomon.

(BTW He now seems to have a bee in his bonnet about the UN. Don't know what kicked that off - don't care either.)


A denier was also a medieval coin. Fittingly, the smallest value in circulation.


Bill & Bob: At least we can understand you. I remember reading a novel one time and it took me an entire page to find out that the author had gone from the present to the past based on one word "read". Hows that for english. Had to reread that page to really understand what he was talking about.


OT to Neven

Congratulations – Austria won the Eurovision Song Contest with this song;

”Waking in the rubble….
And rise like a phoenix
Out of the ashes
Seeking rather than vengeance
You were warned
Once I'm transformed
Once I’m reborn
You know I will rise like a phoenix
But you’re my flame ”

“You know who you are - we are unity and we are unstoppable."

C.f. http://www.bbc.com/news/entertainment-arts-27360310

Al Rodger

The UAH Lower Troposhphere Temperatures for the Arctic Ocean continue to drop from the record levels of Jan & Feb and are now (ie for April) down to more 'normal' levels (as graphed here).
The Surface Sea Temperatures from NOAA's nomad3 shows the Arctic Ocean as a whole & the high Arctic continuing at record temperatures for the time of year (as graphed none-too-clearly here).

Congratulations – Austria won the Eurovision Song Contest with this song;

Thanks, P-maker, but I'm Dutch (who came in second). ;-)

Even though I'm not a Eurovision-fan, I'll listen to the songs later this evening.

Daniel Bailey

"Sadly, the term "denier" has inescapable overtones following the Holocaust."

The evidence for man-made global warming is as final as the evidence of Auschwitz.

No other word will do.


Hidden network of methane found on East Coast of New Zealand


Not pretty... We don't want the seas to warm...

Jai Mitchell


Davy, B., I. Pecher, R. Wood, L. Carter, and K. Gohl (2010), Gas escape features off New Zealand: Evidence of massive release of methane from hydrates, Geophys. Res. Lett., 37, L21309, doi:10.1029/2010GL045184.

A >20,000 km2 field of sea floor depressions on the southwest flank of Chatham Rise, New Zealand provides evidence of episodic formation of GEF’s during glacialinterglacial cycles. We interpret dissociating methane hydrates as the most likely cause of gas release.

Dissociation of gas hydrates at the deep‐water BGHS is dominantly the result of pressure decrease, which is greatest at peak stage glaciation, due to the accompanying ∼120 m drop in sea‐level. The pressure effect is potentially enhanced by the coincident arrival of warm temperature
pulses at the BGHS.


It has been hypothesized that a significant slowdown of the Meridional Overturning Circulation in this region would lead to a rapid warming and evidence exists for regular methane pulses during glacial stages (lower water depths)

Just another potential non-linear threat associated with a breakdown of the ocean conveyor current, as has been recently witnessed in the southern hemisphere.


The increased southward flow of warm waters is balanced by a decrease in the southward flow of lower North Atlantic deep water below 3000 m. The transport of lower North Atlantic deep water slowed by 7% per year (95% confidence that the rate of slowing is greater than 2.5% per year).


Y' know, if all this data was the printout of the function of my heart's pacemaker I would be very worried indeed. A classic chart of the stuttering engine of our biosphere is Cryosphere's Tale of the Tape


Imagine that was the printout of the revs of the engine of your old lawnmower... Starting out in the 1980s all Brmmmm BrMmmm BrMMmmm BrMMmm but now its mmBrrSplutter-gasp- wheeze-gasp-Brr- Gasp splutter-cough-sputter -- --- die! The classic instability of a complex feedback system in trouble...

Kevin McKinney


Yes. It's entirely obvious--except for those Holocaustically challenged, chronically perforated, or Medievally monetary (in a small way, of course.)

For them, the infamous "Parrot sketch" is only a slight exaggeration. And the Arctic ice is 'only resting.'

Bill Fothergill

Beautiful bird, the Norwegian Blue

Colorado Bob

Collapse of Parts of West Antarctica Ice Sheet Has Begun, Scientists Say

Both papers conclude that warm water upwelling from the ocean depths has most likely triggered an inherent instability that makes the West Antarctic ice sheet vulnerable to a slow-motion collapse. And one paper concludes that factors some scientists had hoped might counteract such a collapse will not do so.

The new finding appears to be the fulfillment of a prediction made in 1978 by an eminent glaciologist, John H. Mercer of the Ohio State University. He outlined the uniquely vulnerable nature of the West Antarctic ice sheet and warned that the rapid human release of greenhouse gases posed “a threat of disaster.” He was assailed at the time, but in recent years scientists have been watching with growing concern as events have unfolded in much the way Dr. Mercer predicted. (He died in 1987.)

Hans Verbeek

Hi Neven.
What are your thoughts on the negative feedback of increased precipitation as suggested by Bintanja & Selten in Nature ?

They suggest the increased precipitation (snow) may slowdown the melting of the Greenland icesheet, other glaciers and Arctic sea-ice.
The increased evaporation and precipitation in the Arctic may even slowdown the rise of the sealevel.


Hi Hans, I had just read your blog post on the subject.

Increased precipitation is obviously one of the most logical negative feedbacks, which is probably already playing a part. The question is how this negative feedback scores against the positive feedbacks and the forcing in general. And also what the consequences of this negative feedback can be (I see the paper mentions freshening of the Arctic Ocean).

It's clear that increased snowfall during winter influence the mass balance of glaciers and ice caps (as does more rain in fall), but I'm not sure that increased snowfall will preserve sea ice. I thought that sea ice thickens less when there's an insulative layer of snow on top of it.

If we really want to find out how much the Arctic - and by extension the global - climate can change, we need to burn as much tar sands, lignite and Arctic oil as possible.


Whatever PIOMAS and volume may hold, I'm a bit surprised after going over MODIS tonight. Especially the r05c04 tile 'New Siberian Islands'.
Near Wrangel the ice is breaking up extensively. The polynia near the Novosibirsk Islands is even larger than the same in June '13. Though there are no melt ponds in vue yet, the severe cracking over most of the tile area does seem to indicate a quality that is weeks ahead/worse than last year...


Hi everybody, I have been absent due to a broken telephone cable.
Coming back I noticed that after I wrote this about the PSC thickness graph:

The PSC graph shows average grid cell thickness. That is they add up all grid cell thickness measures and divide that by the number of grid cells.

So it is not a true area-averaged number: the smaller grid cells have a relative overweight.

The next day PSC changed the graph! I haven't looked at it in detail, but would not be surprised if the average is now more area-weighted and perhaps more in line with Neven's graph.

Bill Fothergill

Neven wrote...
If we really want to find out how much the Arctic - and by extension the global - climate can change, we need to burn as much tar sands, lignite and Arctic oil as possible.

You seem to have neglected the "slash and burn" possibilities inherent in the Taiga.

Also, if some buildings up the the frozen north are suffering stability problems due to their foundations being compromised by tempafrost (new name for permafrost), then a few dozen cement production factories could be just what the doctor ordered.


Not to mention the need to stabilise lots of new roads and railways built on top of tempafrost:



Hans Verbeek

Thanks for your reaction.

we need to burn as much tar sands, lignite and Arctic oil as possible.
Let's not even try that. It is not our purpose in life to try that.

Chris Reynolds

New post up with analysis of starting conditions for the 2014 season.

Looking good for something exciting. ;D


My thickness calculations now seem to be more like theirs! Thanks for that.


Hi Chris,
Thanks for the analysis. I think you set up a good reference-line for the deploying season.
As I suspected based on 'winter power', the Bering side doesn't look good. You illustrated that.
It will be 'fun' to see how and if a developing ENSO event might affect the sea ice.


@Jim: From a source closer to 'home'.


AS for the Antarctic there are 2 views.
Very Bad:http://www.huffingtonpost.ca/2013/07/30/us-cities-sinking-climate-change_n_3676325.html
Based on what has happened in the Arctic, I would be more inclined to be a pessimist.


@LRC- A recording of the NASA press conference about the WAIS "collapse"


Hat tip to checkmate

Artful Dodger

Hi Wipneus,

Axel Schweiger (PIOMAS Principle Investigator and current Chair of the Polar Science Center PSC at UWash) acknowledged and thanked you for your contribution in the PIOMAS April 2014 thread.

I think that's also worthy of a mention in this MAY PIOMAS THREAD, too.

Well Done, Wipneus! +1



Another changing mechanism.
As has been noted before, those waves can reach 10s of miles into the pack ice because of its poor condition. Even pack ice that is known to be thick.


Lodger: yes Neven notified me of dr Schweigers post.

I am glad we are able do something useful in return for (and with) all the data we get every month.


Thanks Jim/checkmate: Makes one think that the most important line for the Antarctic is not extent but grounding line. Although that one would have to have a satellite that see through the ice and 'see' the water between the ice and ground.


Way O/T http://www.businessinsider.com/cities-exposed-to-rising-sea-levels-2014-4
Just a thought crossed my mind. If there is anyone with kids out there encourage them to go into engineering specializing in flood control and/or dike work. See the red swashes for the 2 metre make that a few have said could happen by 2100.


Also O/T.

Tropical storms migrate toward poles



Derek, really off topic...

On the Forum, Jai Mitchell just posted this link: http://earth.nullschool.net/#2014/05/19/0600Z/wind/surface/level/overlay=mean_sea_level_pressure/equirectangular=-32.05,-40.34,819

Looking at the circulation patterns in the North and South Atlantic on the 19th May, one could get the impression, that two tropical cyclones are forecasted...

Chris Reynolds

Thanks Werther,

If you need breakdowns for areas other than Beaufort/ESS/Central, I can provide.


P-maker: Very nice site. Really gives one prospective on how interconnected everything is and gives one reasons to get back to work ;).
Combine that with heat maps and one can see how the heat and cold is getting pushed around.
Looking a the Arctic myself right now.
In case your new to it, it can zoom in and out (very nicely with a wheel) and left clicking it gives wind speed.


Check out around the Fram.Surface temps with Ocean currents
a visualization of global weather conditions

forecast by supercomputers

updated every three hours

ocean surface current estimates

updated every five days

ocean surface temperatures and

anomaly from daily average (1981-2011)

updated daily


OOps forgot the link:


Having way too much fun http://earth.nullschool.net/#current/wind/isobaric/850hPa/overlay=wind_power_density/orthographic=-210.79,85.03,863
Some of the variables such as hPa and map type such as azimuthal_equidistant and orthographic. You can also pick days and times (from that data bases they use) back to Nov 1/2013. Do not know where they archive it or how long they will keep it.

Jai Mitchell


the posting at the bottom was supposed to show how an extreme ridge was setting up in the atlantic. There are some pretty extreme blocking patterns starting now. Just like they did last year.

The idea that I have is that these blocking systems are forcing increased moisture into the arctic that contribute to intensified low-pressure systems and colder temperatures.

Remko Kampen

"There are some pretty extreme blocking patterns starting now." - By Jai.

Indeed, and I have to note once more that over 30 years of experience with north Atlantic circulation patterns are down the drain.
But I'm beginning to see the picture, I think, and it is dead simpel. A very strong poleward shift of the subtropical dynamical high pressure band. See http://globalweatherlogistics.com/seaiceforecasting/gfs.500mb.height.anomaly.arctic.html . The strangest feature to me is the strong increase of these warm highs in an area we used to know to be 'forbidden' for this, that is around Newfoundland/South Greenland.

Chris Reynolds

Remko, Jai,

I'm not aware of Newfoundland/South Greenland being forbidden for GPH highs. What I'm seeing is a mix of May 2007 and May 2012.
May 2007.

In 2012 May showed average anomaly ridge south of Greenland and into Baffin Bay, surprisingly similar to the end of sequence on GWL's 500mb GPH animation.

Westwards of the Lena River is seen a tendency to trough in the GWL anim, in 2012 this was apparent in the May average on NCEP/NCAR. There was much stronger troughing in May 2007 in the same region.

Towards the end of the GWL anim is seen a large block forming over the Pacific wing of Siberia, a dome of gph was seen in the same region in 2012.

In 2007 there was a strong blocking high in Bering (semi-permanent feature).

Aside from the north Atlantic, which in 2007 was low dominated and in 2012 low tendency. I think a mix of 2007 and 2012 is a reasonable interpretation....

I admit you could probably play a similar game with other years. But my point is I see little evidence for conditions indicating a re-run of 2013 is on the cards. For comparison here is May 2013 500mb GPH.
The action around Greenland was opposed to what is going on this year. And it is unusual intensification of the Greenland ridge that has charcterised summers from 2007 to 2012, yet failed to mainifest in 2013.

As for May 2014 so far, here is NCEP/NCAR 500mb GPH to 12/5/14.
This is markedly different from 2013's May average.

For completeness here are the sfc temps for May 2014 so far:
And the same period in May 2013.
It was in the second half of May that temperatures dropped across the pack stalling the start of melt in June.

I should add that I've wasted a lot of time trying to find a precursor to the Greenland anomalous GPH ridging during JJA 2007 to 2012. I've not found one. However it seems that the anomalous Greenland GPH ridging is what is setting up the Arctic Dipole common to those years and this is in turn linked to the large retreat of sea ice in the Siberian sector in all summers, apart from 2013, e.g. Bluthgen et al http://onlinelibrary.wiley.com/doi/10.1029/2011GL050486/full

Given the number of links in this one I suspect I'm destined for the spam filter...

Here goes. ;)


Hear hear Chris, it is more like 07 and 12, with a tinge of 08 and 11. Especially with El-Nino now on, getting stronger. On top of that, the European ECMWF model seems to agree. The High more often over Beaufort sea is key:


Jai Mitchell

Chris, Wayne

my idea (and it is simply an idea based on 3 years of observation) is that a static high pressure system curled under Alaska moves moisture laden air into the arctic circle (leaking into the polar cell) which feeds the polar vortex and generates low pressure anomalies.

This is what it looks like right now. The current low formed from the blocking pattern a few days ago: http://earth.nullschool.net/#2014/05/15/2100Z/wind/isobaric/850hPa/overlay=total_precipitable_water/equirectangular=-169.35,64.65,965

If you compare your NCEP/NCAR reanalysis for 2007 and 2012 you will find a low pressure anomaly below Alaska. For 2013 and now 2014 you will see a high pressure anomaly.

similarly you can simply compare the sudden dip in 80N-90N temperatures between 2013 and Now They are identical and happened at the same time of the year.


Is it possible that this is a signal of geoengineering. . .perhaps in response to the 2012 summer?

What is your July average NCEP NCAR reanalysis for 2012 look like? can you post that please?

Jai Mitchell

This is the pattern that set up the low pressure anomaly in the arctic. It lasted in this pattern for 5 days.



Jai, I think you are spot on!

Since 2004, the Earth has been heated up due to GHG emissions to such an extent, that natural ”heat pumps” were dominating global climate. Both 2004, -5, -6 & possibly 2007 were dominated by tropical cyclones, which were essentially evaporator-dominated heat pumps on a global scale. It was the evaporation of waste amounts of humid air over the Tropical Oceans, that drove these Tropical heat pumps. The end result was a cooling of the Tropical oceans (also known as a decade of La Nina’s or a halt in global warming).

Since 2012, the Earth has moved into a condensator-dominated “Chiller”-mode, which is dominated by persistent Arctic cyclones. Condensation in the cold cores of these phenomena takes out energy from the surface of the Arctic Ocean (hence the below normal 80N+ surface temperatures in recent years from DMI) and delivers heat aloft. It is the condensation of the humid air from lower latitudes, which drives the Arctic chillers. A shift of lower latitude high pressure cells may contribute, but essentially it is the chillers driving the process.

As long as we have cold ice in the Arctic Ocean (and high pressures with sublimation of snow over the continents) during spring, we will have this chilling effect in operation.

At some stage in the future, the chiller will start working before the Arctic marginal seas have cooled down. This means that the evaporation of warm marginal seas water will lead to a late autumn/winter humidity content in the air, which requires more surface cooling than the sea ice can provide. The result will be a perennial ice-free Arctic Ocean.

Jai Mitchell

I see it differently.

The hydrological cycle of the tropics hasn't changed all that much (with the exception of the artificial column of abnormally dry and rapidly rising midtropospheric air over the Tropical Indian Ocean warm pool, moving vast quantities of low-altitude sulfates into the stratosphere. . .but I digress in the first sentence).

The "chiller-mode" you are talking about is, in my view, a breakdown of the polar cell due to warming and the forcing of stronger, longer lasting blocking pattern high pressure systems.

The introduction of this moisture laden air adds significant energy to the polar vortex and as this moisture cools and the air condenses it forms a strong and pervasive low pressure system that produces a significant cooling IN THE SUMMER MONTHS due to cloud-albedo.

The energy for these systems are not being drawn from the surface of the arctic ocean. It is being introduced from mid-latitudes.


Jai, the Highs South of Alaska will have a hard time because of North Pacific warm temperature anomaly. it may be interesting to see if El-Nino drives its existence. But the High pressure to watch occurs between beginning of June to end of July over the Arctic Ocean basin or gyre, whether it reinvigorates the gyre or not is key. It has been more common than last year, with clouds now taking over the entire Arctic Ocean as they usually do at this time of the year, it will be interesting to see if the coming ECMWF High over the Basin will be cloud free or not. But I tend to think that there are plenty of reasons to imagine more cloud coverage this summer and much more this fall. Especially by El-Nino. which warms as well as seeds clouds worldwide, reshapes the patterns as well. 2012 had a mild mini El-Nino which affected the circulation with Ice melt results well known. So the determinant for a greater melt is whether the thicker ice on Canadian side will help sustain an Anticyclone when the sun is high enough for maximum impact. Having a permanent low pressure dominance like summer of 2013 is not sustainable forever because of outside and inside influences which change chaotically.

Remko Kampen

"I'm not aware of Newfoundland/South Greenland being forbidden for GPH highs." [Chris Reynolds]

Such highs near the Cold Wall (this is where Labrador- and Gulf Stream meet) rarely lasted a day, that is they used to form an endless chain of fast moving highs turning Azores.
Blockings in this region used to be rare and shortlived. In fact the only convincing one I knew until a few years ago was this one: http://www.wetterzentrale.de/pics/archive/ra/1985/Rrea00119851101.gif .

I coined the term 'Sandy High' for them. That was the first convincing one (resulting in the very first hurricane making a left turn like she did). Since this strange pattern or things like it have become almost common. An immediate repeat of Sandy was the Nemo winter storm situation a month or two later.

Enjoyable archive: http://www.wetterzentrale.de/topkarten/fsreaeur.html .

The pattern coming week exhibits the pathology again. It is as if (only: as if!) a much weakened circumpolar jet coincides with the subtropical jet while the Arctic jet, usually a nondescript feature, is displaced slightly to the north and vastly stronger than climate used to be. This sickish pattern seen first half July 2006.

To be sure, such patterns have occurred in history many times too, but the crucial difference is they used to be transitional circulations lasting two days at the very most, while they stick like glue these years.
Generally there is a very measureable increase in length of duration of any Atlantic pattern - over +50% by 2010, perhaps already double now. Average duration used to be 3-4 days, became 5-6 by 2010 (reference: http://www.pik-potsdam.de/research/publications/pikreports/summary-report-no.-119 ).

Chris Reynolds


July 2012, 500mb gph anomaly.

Average July 500mb gph anomaly for 2007 to 2012.


I'm sorry but I just don't buy it that "The current low formed from the blocking pattern a few days ago". But I need to be clear.

On 9th May 2014 there was a high to the south of Alaska adjacent to the Bering Sea. Are you saying the the flow across Bering created the low observed in the Atlantic sector of the Arctic Ocean?

The Low in the Atlantic Sector originally formed from a state (2/5/14) where the Canadian Arctic was high dominated (a ridge, from Beaufort to the Atlantic ice edge. Note that due to low ice extent in the Barents Sea that region has seen many lows since January, low pressure was also evident on 2nd May 2014 over Barents.

Then on 3rd May the Canadian Arctic ridge retreated to Alaska, and a tongue of low developed from the existing Barents low.

This low then intensified and moved towards Beaufort, deepening to around 995hPa by 6 May. It then weakened and moved towards the Atlantic, by 8 May it had deepened agin to 990hPa. At which time a weak low existed over the Gulf of Alaska.

By 10 May the same low had arrived back in the Barents Sea, where low sea ice has been creating lows all winter. At which time it had intensified to 985hPa.

By 12 May the system had largely dissipated, the centre of action of the 500mb GPH trough being over Svalbard.

So, if we are talking about the same low, then I don't buy your interpretation because the low actually declined in intensity as the transient high over the Gulf of Alaska formed, and only increased in intensity when it got back to Barents - the centre of action for a lot of low pressure. That thi is the centre of action for many lows makes sense because during the winter with reduced ice cover it has been able to produce convective lift against the colder air masses over the pack and Siberia.


I can't read German so can't make use of the paper you linked to. Does that paper address blockings in the region just south of Greenland?

Jai Mitchell


On 9th May 2014 there was a high to the south of Alaska adjacent to the Bering Sea. Are you saying the the flow across Bering created the low observed in the Atlantic sector of the Arctic Ocean?

No, I was not speaking of the Atlantic sector but rather the CAB, as I posted on the forum here: https://forum.arctic-sea-ice.net/index.php/topic,784.msg26006.html#msg26006

The Series of North West blocking patterns that set up on the 10th and lasted through the 14th funneled significant low and mid-altitude moisture into the CAB which fed the resultant low. http://earth.nullschool.net/#2014/05/11/2100Z/wind/isobaric/850hPa/overlay=total_precipitable_water/orthographic=-169.22,64.01,922

here is the low
initial formation: May 14th http://earth.nullschool.net/#2014/05/14/2100Z/wind/isobaric/850hPa/overlay=mean_sea_level_pressure/orthographic=-169.94,82.88,922


The projected increase on the Atlantic side won't really happen until the 19th. I have only some observation of this area but see a very unusual blocking pattern setting up, posted here: https://forum.arctic-sea-ice.net/index.php/topic,784.msg26013.html#msg26013

I did not say specifically that this was producing an arctic low but a very large low pressure formation is setting up, largely as a result of mid-atlantic water vapor moving up to the north sea.

The setting up of a North East Pacific high-pressure blocking ridge (under the Aleutians) is heavily represented in GeoMIP


The negative PNA-like pattern in G1-
piControl is associated with a westward shift of the jet stream toward East Asia, blocking activity over the high latitudes of the North Pacific Ocean, and a strong split-flow configuration over the central North Pacific Ocean. Figure 7 displays these features with a decreased jet speed over central, west Pacific region (with across-model differences, Figure S7), and the 200 hPa geopotential height map also shows a “blocking” high pressure over the northern North Pacific under G1.

If it is possible to use regionally-targeted geoengineering to establish the spring-summer blocking high pattern in this region, as was observed in 2013 and now again in May 2014, then this may be a way to reduce CAB temperatures to below normal and help to stabilize arctic ice loss:


Francesco Meneguzzo

Hi all! I might go a little OT - anyway I'd like to share with you an astonishing (should say inconvenient=? :) ) truth arising from a bulk of research about real climate forcing power of fossil fuels.

Although I smelled something strange few years ago after few colleagues in my institute measured unexpected methane leaks from the grid of urban gas pipes - http://dx.doi.org/10.1016/j.envpol.2012.01.019 and http://dx.doi.org/10.1016/j.egypro.2013.08.062 - a true atomic bomb on conventional methane, besides of course fracking one, was launched by Prof. Howarth from Cornell University with his recent paper on Energy Science & Engineering http://onlinelibrary.wiley.com/doi/10.1002/ese3.35/abstract

It's worth pasting the abstract, while recommending a full reading:

In April 2011, we published the first peer-reviewed analysis of the greenhouse gas footprint (GHG) of shale gas, concluding that the climate impact of shale gas may be worse than that of other fossil fuels such as coal and oil because of methane emissions. We noted the poor quality of publicly available data to support our analysis and called for further research. Our paper spurred a large increase in research and analysis, including several new studies that have better measured methane emissions from natural gas systems. Here, I review this new research in the context of our 2011 paper and the fifth assessment from the Intergovernmental Panel on Climate Change released in 2013. The best data available now indicate that our estimates of methane emission from both shale gas and conventional natural gas were relatively robust. Using these new, best available data and a 20-year time period for comparing the warming potential of methane to carbon dioxide, the conclusion stands that both shale gas and conventional natural gas have a larger GHG than do coal or oil, for any possible use of natural gas and particularly for the primary uses of residential and commercial heating. The 20-year time period is appropriate because of the urgent need to reduce methane emissions over the coming 15–35 years.

It looks like that while we're all concerned with leaks from permafrost as well as from submarine methane clathrates,the ordinary pipes are already doing a very good job against the climate - about double as good as coal... please read to believe.
Hopes are quickly vanishing, isn't it?

R. Gates


Thanks for mentioning this. Yes, indeed these direct leaks of methane from oil and gas drilling and transmission are far larger than the industry would like to have known. These leaks, going on now worldwide as fracking has exploded around the world, are adding insult to injury in regards to their additional contribution of methane in addition to the permafrost melt, new biological sources being activated by permafrost melt, and methane hydrate destabilization going on globally. While we've mentioned it many times here, I think as serious as CO2 is, methane looms as the issue requiring even more attention right now. Sadly, I am not optimistic this will occur.

Chris Biscan

we are entering unprecedented territory and the worst is still to come. We haven't seen anything yet. So far this is all wind driven and solar maintained.

Solar prevents freeze up but the melt hasn't really started on the Russian side. But that is about to dramatically and radically change.

Oh and the winds are expected to continue to blow the ice towards the Atlantic.

I have zero doubt if this dipole continues into mid June this year will be like 2007 was in it's time.

Chris Reynolds


The scenario as you now state it (we were looking at different lows) is more feasible.

With regards the final line in the abstract of the Moore et al paper you linked to. Coincidental with the 1975ish start in linear GW (~0.2degC/decade), the PNA seems to show a step jump into positive index behaviour. Using JFM average PNA index for 1950 to 2014 the 1950 to 1964 average is -0.301, the 1975 to 2014 average is 0.284. The 1950 to 2014 std dev'n is 0.691. But I've not got time to read the whole paper, sorry.

Remko Kampen

Chris, on that German text. In short, a long time ago German climatologist Franz Baur devised a categorisation for North-Atlantic circulation types. They number 24 plus a bucket for 'transitionary' flows.

Then, there is a statistic as of 1900, daily. Notes:
- Such a pattern on average used to exist for 3-4 days.
- A transient pattern, however, 1-2 days.
- There is no relation whatsoever between two successive patterns.

In the 2010 report, find Fig. 12, showing the increasing trend in 'stuckness' of patterns (any).
While the graph there seems to taper down a bit, the effect has nevertheless increased since.
But in 2010, the Newfoundland-Greenlandblock didn't take existence time like it does today. The article, and the original catalog, doesn't mention it as a specific pattern. This may be explained partly for its rareness and the fact that the catalog tried to be relevant for Europe, rendering such a 'Sandy block' into different patterns depending on the location and length of the trough to its east (Germany could get both northwesterly and southerly air flows from it and they are considered widely different patterns).

Better leaf through all and sundry in the charts archive, methinx. I know a lot of them but confess I didn't go through absolutely every summer's day.

Jai Mitchell

Final Line in Abstract:
The tropospheric circulation displays a Pacific North America pattern-like anomaly with negative phase in (Geoengineering Sumulation) and positive phase under abrupt4xCO2-piControl.

PNA index trend here:

Source page here:



Having just finished your paper I have to say it's the scariest thing I've ever read.
Could I ask you to start a thread on it at the forum where we could debate some of the implications?
As the world is set to embark on a fracking frenzy it may be important to step back and consider the 10 & 20 year effects of CH4. Fig. 1 indicates that even over a 100yr period gas may be more damaging than coal.


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