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Hi Neven,

Is PIOMAS having difficulty with sea ice thickness in some areas? Am I suppose to believe that there is 1.5 meters thicker sea ice in the Barents sea area, must be from always water measured in the past? Usually of latest years quite open with water for a great chunk of winter?

Using temperature anomalies and precipitable water, these questions needs answers or counter arguments:


John Christensen

Thank you for another great update Neven!

I am noting for the past three months:

Year Feb 28th May 31st Relative gain March-May '18
2007 -2429 -1880 549
2008 -3121 -2867 254
2009 -3203 -2420 783
2010 -2295 -218 2077
2011 -825 528 1353
2012 -1073 420 1493
2013 -1269 -487 782
2014 -1231 -286 945
2015 -2849 -1490 1359
2016 -949 690 1639
2017 1034 1915 881

I will do some more review of this soon.

John Christensen

And sorry for my miserable graphics skills!


I have always suspected PIOMAS being very conservative with volume estimates, here is some proof:


So I suspect the real volume of the entire ice pack to be overestimated. Makes sense given the smaller sea ice extent numbers and especially the very warm Arctic Ocean winter just past.

John Christensen


I do not agree with the points made above:

"I have always suspected PIOMAS being very conservative"

Well, DMI has a higher volume estimate, picking up more close-to-shore ice than PIOMAS I believe.

"Come June there was no evidence of multi year sea ice migrations, it is just new sea ice. It is conservative to estimate that this ice had only 3 months to accrete, which is definitely not possible to thicken so quickly beyond 150 cm,"

The sea ice clearly does not thicken to 150 cm due to the accumulated freezing of sea water: It happens via wind and current driven ridging. Nothing spectacular about that given the weather in the region in the past few months.



"The sea ice clearly does not thicken to 150 cm due to the accumulated freezing of sea water: It happens via wind and current driven ridging. Nothing spectacular about that given the weather in the region in the past few months."

Ridging is an obvious effect of great lengths of time, I don't see it here, it does not show well at all... Rather it is thin sea ice, easily broken, the red +1.5 m anomaly should be uniform throughout, according to evidence presented, Novaya Zemlya Island is an anti-ridging natural enclosure as well.


I have added a bonus PIOMAS red zone thick ice feature loaded with open water for most of May 2018. explain this one John :)


John Christensen

Hi wayne,

I'd agree for northwest NZ on the Barents side: The DMI volume chart also does not indicate much sea ice here.

For Kara: Here we saw temperatures considerably below normal for March and April, combined with storms, likely considerable precipitation, which submerges sea ice and more rapidly builds new ice as mix of snow and freezing sea water on top of ice.
The Kara ice pack during those two months moved from the Siberian side to NZ and back a few times, which helps with ridging and the DMI chart today is in reasonable agreement with PIOMAS here, so if not fully accurate I would still find the estimates reasonable as any model estimate could be.


Yes John

Kara Sea has signs of significant melting about:


There is more action everywhere over the Arctic Ocean...


Thank Goodness for the SWITCH in pressure scenery, cyclonic clouds shade the sea ice from most direct sun rays over the gyre area. This switchover was projected in April, came about as I expected, about mid June. It is a great accomplishment in projecting the future, I must say this myself, because I am certainly working to get the Nobel prize in achieving something while being ignored :)


Susan Anderson

Currently large amounts of the surface at the North Pole are above freezing

Also, significant warmth @ western Greenland and northeastern Canada, fwiw.



Thin sea ice covered with thick snow playing games with our eyes and also algorithms


The key is judging how mega ice pans break up...


Greening sea ice is a sign of melt ponds, particularly strong on the Russian side of the Pole this melt season, with open water pretty much exceeding 2012.




Al Gore told us this stuff will take atleast 20 years!!


2012 melt is in the cards by mainly one reason, the speed of sea ice velocity in the Beaufort sea area, twice as fast at peak before cyclonic switchover:




Also, Wayne, when was this 'cyclonic switchover'?


About June 8 or 9, is when the gyre became dominated by cyclone(s) as opposed to anticyclone(s).

John Christensen

Amazing that a headline with "CO2 Shortage" should appear - and sorry in advance for the highly irrelevant piece of news Neven! ;-)


John Christensen

Sea ice related:

Neven, your regular bi-weekly updates on melting progress are very much missed, will they be forthcoming or will you focus on the monthly PIOMAS updates and combine as open threads?

So far for June I have noted:
- Weather stays 'blend' without any significant highs or lows, which overall is good for the ice cover
- DMI reported that the 80N average temp. moved into melting territory one day later than average, which also is good
- DMI sea ice volume for June has been trending above 2004-2013 average with below-average sea ice melting for the fourth consecutive month, which is rather impressive given the relatively warm winter and very low SIA/SIE this spring

In summary, I am still satisfied with my 4.85 - 5.35 (V3) Sept average SIE provided on June 8th.


Will we see your updated estimate soon?


The speed of sea ice over the Beaufort and other areas has increased extent by scattering sea ice over already open water, by misfortunate lack of adjusting to the new reality of collapsed sea ice from within, extent increases in some regions but of course no new ice was created.
There is a vast difference between 2012 though:


If solar forcing is similar to 2012, so will be extent, although by rather different geophysical means.

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