PIOMAS Arctic Sea Ice Volume Model Corrected – Still Appears Suspect

By WUWT regular “Just The Facts”

It seems that the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS) Arctic Sea Ice Volume Model that generated the highly suspect chart above has been corrected to “show reduced errors over the prior version”. According to the University of Washington Polar Science Center website:

“New Version

This time series of ice volume is generated with an updated version of PIOMAS (June-15,2011). This updated version improves on prior versions by assimilating sea surface temperatures (SST) for ice-free areas and by using a different parameterization for the strength of the ice. Comparisons of PIOMAS estimates with ice thickness observations show reduced errors over the prior version. The long term trend is reduced to about -2.8 103 km3/decade from -3.6 km3/decade in the last version. Our comparisons with data and alternate model runs indicate that this new trend is a conservative estimate of the actual trend. New with this version we provide uncertainty statistics. More details can be found in Schweiger et al. 2011. Model improvement is an ongoing research activity at PSC and model upgrades may occur at irregular intervals. When model upgrades occur, the entire time series will be reprocessed and posted.”

Here is the PIOMAS New Model Version:

and the chart below appears to show the original “Adjusted” version and the new unadjusted version:

Correction: Per this comment the chart below actually represents an “exercise” “not designed to correct potential model biases” when the “model appears to overestimate thin ice and underestimate thick ice.” The impact of this “exercise” is that the “downward decadal trend increases from -2.8×103 km3/dec to -3.5×103 km3/dec” which is the inverse of the impact when they “reduced errors over the prior version” and reduced the trend “to about -2.8 103 km3/decade from -3.6 km3/decade”, however the chart below does not show “the original “Adjusted” version and the new unadjusted version” as was incorrectly stated above.

If you look here you can see how Dr. Jinlun Zhang developed his suspect model. The page states that;

“Satellite sea ice concentration data are assimilated in GIOMAS using the Lindsay and Zhang (2005) assimilation procedure. The procedure is based on “nudging” the model estimate of ice concentration toward the observed concentration in a manner that emphasizes the ice extent and minimizes the effect of observational errors in the interior of the ice pack.”

According to this paper:

“Because of the errors in the summer Gice dataset ice concentration in the interior of the pack (as well as errors in summer ice concentration based on passive microwave observations), assimilation of ice concentration is accomplished in a method that emphasizes the extent over the concentration. The observations are weighted heavily only when there is a large discrepancy between the model and the observed concentration. Each day the model estimate Cmod is nudged to a revised estimate Ĉmod with the relationship.”

So it appears that to develop his model Zhang used an erroneous data set, weighted heavily when observations didn’t fit the model and then “nudged” its output to the results that he wanted.

Zhang has a history of contorting himself to help paint over the gaps in the Catastrophic Anthropogenic Global Warming Narrative. For example, in this NASA article/press release it states that:

“Jinlun Zhang, an oceanographer at the University of Washington, has pieced together a complex computer model that helps explain why Antarctic sea ice is expanding even with signs that ocean and air temperatures are on the rise.”

and in this paper titled “What drove the dramatic retreat of Arctic sea ice during summer 2007?” by Zhang, J., R.W. Lindsay , M. Steele, and A. Schweiger, Geophys. Res. Lett., 35, L11505, doi:10.1029/2008GL034005, 2008, it states that “Arctic sea ice in 2007 was preconditioned to radical changes” and this contributed to “The dramatic decline”. This is not objective science, rather it’s alarmist rhetoric.

Zhang was already looking for an Arctic Sea Ice tipping points in 2005, i.e. the title of this paper paper was “The thinning of arctic sea ice, 1988–2003: have we passed a tipping point?” by Lindsay, R. W. and J. Zhang, J. Climate, 18, 4879–4894, 2005.

In 2006 Zhang co-wrote a paper with Mark “Death Spiral” Serreze and Keith “the lack of warming … is a travesty” Trenberth, titled “The large-scale energy budget of the Arctic” by Serreze, M. C., A. P. Barrett, A. G. Slater, M. Steele, J. Zhang, and K. E. Trenberth, , J. Geophys Res., 112, D11122, doi: 10.1029/2006JD008230, 2007.

Zhang’s history of global warming advocacy aside, I give him credit for correcting his model to reduce the trend from -3.6 km3/decade in the last version to about -2.8 km3/decade in the New Model Version, so that is now less wrong. Then again, he is probably just hedging because, per this article, CryoSat is now generating maps of sea ice thickness and it is just a matter of time before Zhang’s model will be confronted by empirical evidence.

I wonder if all of the Warmist blogs that have used the old inaccurate PIOMAS chart will post updates/corrections to inform their readers of the good news…

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67 Comments
Pamela Gray
June 29, 2011 11:10 am

R. Gates says:
June 28, 2011 at 10:55 am
“What does it really matter that first ice free summer is 2025, 2030, or 2040? The trend is what is important and it’s down down down…”
Nonsense. What really matters are the weather and oceanic pattern variations that have caused that decline. Stop with the numerology.

FergalR
June 29, 2011 12:06 pm

Julienne Stroeve says:
June 29, 2011 at 12:42 am
[…]Have you noticed that sea ice thickness in Baffin Bay is 3m? That is not possible from thermodynamic ice growth using observed Oct-Feb air temperatures (remember first-year ice is typically 1.5m).[…]
——————————-
Dr. Stroeve,
During the bitter winter here in Europe we were constantly told how warm it was in Greenland. I understand that this was due to a high pressure system trapped up there. I’m not a meteorologist but I understand that high pressure usually means little or no cloud.
Without the insulating effect of clouds isn’t it something other than impossible that the first year ice in that area is thicker than normal?

R. Gates
June 29, 2011 4:53 pm

Pamela Gray says:
June 29, 2011 at 11:10 am
R. Gates says:
June 28, 2011 at 10:55 am
“What does it really matter that first ice free summer is 2025, 2030, or 2040? The trend is what is important and it’s down down down…”
Nonsense. What really matters are the weather and oceanic pattern variations that have caused that decline. Stop with the numerology.
_______
Of course it was weather (by this, I take you mean everything that happens in and through the atmosphere) and oceanic variations…what else can affect the ice? Either heat comes from above or below, but either way, the heat has come. But what you’re probably trying to suggest here is that it is all simply natural variations is the weather, and so nothing outside of natural variations (meaning nothing anthropogenic) is causing the ice to decline. Puny humans, no matter what we do, cannot possible affect the big ol’ earth, right? Certainly not the tons of extra CO2 we add to the atmosphere. And those hundreds or perhaps thousands of experts in the cryosphere, who have have been watching the Arctic sea ice decline for decades and studying pretty much every possible facet of it and documenting those changes in graphs that tell the story of the decline are just practicing numerology, right?
Meanwhile, as the Arctic sea ice declines steadily, the good folks in skepticville are practicing true science as they anticipate the next glacial period, or at least a mini-ice age to start soon. You’d think the Arctic sea ice would show some signs of at least getting back to it’s long term average if that was going to happen…a place it had not been since 2004.

Pamela Gray
June 29, 2011 5:10 pm

No. I am asking you, as I have on many occasions, what your understanding is on how the rise in anthropogenic CO2 can affect these energy eating weather and oceanic pattern variations in such a way as to no longer point to natural variation, but anthropogenic variation. So far, you have failed on every count to answer this question.

Julienne Stroeve
June 29, 2011 6:26 pm

@FergalR
Looking at the cryosat map, it’s not just Baffin Bay that appears to have too thick of first year ice, you can see the black line on the image that delineates the first year from the multiyear ice. I am at a conference at the moment with many sea ice experts and the map has been heavily discussed. Two points of validation have been used: north of elsemere island that airborne observations indicate has ice around 4.1m thick and a spot in the beaufort that airborne obs indicate is 2m thick. We have learned that sometimes the radar penetrates the snowpack and reaches the ice surface, but many times it doesn’t penetrate the snowpack. So say you have 1m thick snowpack, your thickness would be overestimated by 1m.
Thus, I personally believe it is premature to trust the thickness map they released at an airshow, validation is not complete, snow cover is impacting the retrievals and the magnitude of this bias remains unknown at a broad spatial scale.

R. Gates
June 29, 2011 10:34 pm

Pamela Gray says:
June 29, 2011 at 5:10 pm
No. I am asking you, as I have on many occasions, what your understanding is on how the rise in anthropogenic CO2 can affect these energy eating weather and oceanic pattern variations in such a way as to no longer point to natural variation, but anthropogenic variation. So far, you have failed on every count to answer this question.
———-
I don’t know what “energy eating weather and oceanic pattern variations” are, so sorry, I guess that’s why I’ve not answered this question. I can tell you about what global climate models all say the 40% rise in CO2 since the 1750’s will eventually do to the Arctic sea ice though…they’ll make it go away in the summers sometime this century. So, rather than “energy eating”, the geologically rapid build-up of Anthropogenic CO2 is conducive to keeping more heat around in the oceans and atmosphere and so is sort of “ice eating”.

June 30, 2011 10:28 am

@Julienne,
I’m confused, are you saying ESA released first European ice thickness map to the public only showing a pretty strong polar ice pack and not mentioning 1m snow included?

Rob
June 30, 2011 11:31 am

Julienne, thank you for your insight in the scientific discussion regarding the Cryosat map.
First, I assume that your remark about snow cover was a typo. Of course, because of Archimedes law, only 30 cm in snow-cover-interpreted-as-ice would overestimate the ice thickness by 2 meter. Which seems to be about the overestimate in this map.
Second, you mention 2 validation points, and I posted one above from the Cryosat validation team itself. Are there more validation points available for scientists to study ?
In my opinion, for this map to obtain some scientific credibility, it would REALLY help if the Cryosat validation team would at least publish ALL their validation measurements, and explain the process by which these measurements were considered consistent with the now presented map.

Julienne Stroeve
June 30, 2011 6:09 pm

Dr Haas at the IUGG meeting showed 2 locations in his presentation regarding airborne validation sites used for comparison with the Cryosat map. Unfortunately both were over mutliyear ice. My understanding thus far is that none of the firstyear thicknesses were validated and those regions appear to be too thick based on thermodynamic growth rates and observed winter temperatures. I am sure the Cryosat team is busy doing more validation from their recent field campaign, so we should know more hopefully soon.

Latitude
June 30, 2011 6:32 pm

R. Gates says:
June 29, 2011 at 10:34 pm
I can tell you about what global climate models all say the 40% rise in CO2 since the 1750′s will eventually do to the Arctic sea ice though…
========================================================================
.028 to .039 = .011 increase in 260 years

Rob
July 9, 2011 2:23 am

Justthefacts : it may be too late to reduce your excitement about ‘consistency’ between Cryophere’s first map and PIPS or consistency between both these reports and the real world.
To spoil the fun : It seems that both are heavily biased towards excessive ice volume.
For one, as Dr. Stroeve points out above : the Cryosphere map has been validated with only two measurements, both in multi-year ice, none in first-year ice. Besides, they seemed to have interpreted snow cover as solid ice.
And PIPS was taken offline for a reason :
http://www7320.nrlssc.navy.mil/pips2/
Since late April/early May 2011, PIPS 2.0 has developed an unrealistic opening in the North Pole region. On 22 May 2011, PIPS 2.0 stopped running because of a numerical instability. Since that time, we have been carefully trying to diagnose this problem (checking for anomalous atmospheric forcing, initial fields, boundary conditions, assimilated satellite ice fields, etc). During this process, the system’s ocean model time step was reduced and the system is currently running again. The unobserved opening near the North Pole is still present and can be seen in the ice concentration and ice thickness fields. PLEASE USE THESE FIELDS WITH CAUTION! We have subsequently filled in the period from October 2010 to present with the hindcast using the reduced ocean model time step. Because PIPS 2.0 is a legacy system and will soon be replaced with a new ice nowcast/forecast system (see below), little additional effort will be expended to keep it running.
In short, PIPS will be replaced with a much more updated system. Most of us ice watchers are looking forward to the new system, which you can observe in action (with animations and all) here :
http://www7320.nrlssc.navy.mil/hycomARC/arctic.html
I hope that this new system (the Arctic Cap Nowcast/Forecast System (ACNFS)) will be more accurate than PIPS 2.0, considering that on multiple occasions it reported 4 meter ice where open ocean was clearly visible from MODIS pictures, and in general (despite it’s popularity here on WUWT) seemed to be out of touch with reality. For confirmation of this observation, consider that currently sea ice extent (both in the Actic as well as globally) is breaking all time record lows, and shows no slowdown in breaking the minimium extent record (of 2007).
If you want to see a picture of what really goes on in the Arctic right now, then check this out (latest picture taken at the North Pole) :
http://www.arctic.noaa.gov/latest/noaa2.jpg

Rob
July 12, 2011 12:11 am

Just The Facts says : I made no mention of PIPS in my post or subsequent comments
In this post, indeed you did not. You did however quickly accept Steven Goddard and Anthony Watts, when they used PIPS data (in May 2010) as evidence for significant “ice thickening since 2008”. And you posted no question as to where all that thick ice went between May and Sept 2010 nor questioning about the validity of PIPS.
And you display the same biased opinions when you state CryoSat is now generating maps of sea ice thickness and it is just a matter of time before Zhang’s model will be confronted by empirical evidence
Here, you forget to mention that PIOMAS has been validated by thousands of measurements, while Cryosat first data was so far based on a whopping 2 measurements, meanwhile presenting data for first-year ice (as in Baffin Bay) which is inconsistent with the laws of physics (as Dr.Stroeve rightfully pointed out). Seems to me that Cryosat has a long way to go in being validated, and PIOMAS has a long track record of consistency with emirical evidence.
Instead, you accuse PIOMAS as ” highly suspect” and Zhang of having a “history of contorting himself” and to “paint over the gaps in the Catastrophic Anthropogenic Global Warming Narrative” and “history of global warming advocacy” and other ad hominems.
To top it off, after accusing me of setting a strawman, you place several strawmans yourself in referring to DHI’s melting season temperatures (without mentioning the warm winter clearly visible in the DMI graph) and two papers about ice export through Fram strait (which actually seem to confirm the PIOMAS reduction in Arctic sea ice volume over the past decades.
Just The Facts, I’m not sure who Anthony allows you to post your ad hominems against Zhang, and why he lets you post strong allegations against PIOMAS as well as throwing strawman arguments around that in fact disprove your own pet theories. Without providing evidence for your rethoric and increasingly questionable biased allegations, it seems to me that you could learn something from mother Nature who, despite DMI temps and despite your rethoric about Fram strait, and despite your accusations against Zhang and PIOMAS, provides the best empirical evidence against your increasingly irrelevant opions and rethoric, in breaking all records of ice extent as we speak :
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

phlogiston
July 12, 2011 1:24 am

Julienne Stroeve says:
June 29, 2011 at 12:42 am
I have been surprised that so many are quick to believe the recently shown Cryosat ice thickness map. This map has not been validated. It has not been published in a peer-reviewed journal, it has not undergone any rigorous assessment for accuracy.
You have answered your own question. Owing to the corrupt state of climate academia, peer-reviewed publication does not increase confidence in any “research” but the exact opposite. We regularly see papers on this site that are peer-reviewed and deeply scientifically flawed (e.g. fudgeing the cooling of Antarctica, and all the nonsense on ocean acidification) to know that peer review in the climate field has utterly failed. Peer-review acceptance of a climate related study in a major journal makes it more probable that the work in question is a dishonest politically motivated tract.
Human scientific research and academia is highly fragmented and an insular throw-back to medieval feudalism (perhaps even this is climate – related, since we are now back to medieval temperatures?) Scientific fields are introverted fenced-in little fiefdoms easily and spontaneously dominated by a ruling mafia which proves easy to be subverted by – and become subservient to – a suitable political agenda. I have seen this happen clearly enough in one scientific field to recognise it in the politicized climate arena.

Rob
July 14, 2011 1:38 am

Just The Facts:
I’m not sure if this is the first time that you post a blog as a guest, but let me tell you that as a reader, I don’t think it helps your credibility if you post endless off-topic deliberations about sewer disposals of cruise ships as an argument to sustain your belief systems.
Also, if you post insults against scientists as you do, it would help if you would actually get your facts straightened out. You post this graph :
http://psc.apl.washington.edu/wordpress/wp-content/uploads/schweiger/ice_volume/validation/Fig10.png
and claim that it shows “the original ‘Adjusted’ version and the new unadjusted version”.
This is simply not correct.
The graph presents the difference between the new PIOMAS version adjusted for submarine sonar bias versus the new PIOMAS version unadjusted form.
I pointed that out in a post above (June 29, 2011 at 2:28 am) where this link :
http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/validation/
which clearly shows that unadjusted PIOMAS underestimates thick ice and overestimates thin ice.
And thus, as Zhang readily pointed out “this new trend is a conservative estimate of the actual trend”. And in fact, the sonar-bias adjusted trend is almost identical to the ‘old’ PIOMAS version trend. I’ll dig up a graph if you insist.
So not only are you throwing empty ad hominems at Zhang and vent opinions about PIOMAS results without evidence, you also seem to have no clue at all about the nature of the PIOMAS adjustments and you lack understanding of even the basic evidence that your present yourself. You simply throw out some words and slap some graph around and expect that people are foolish enough to believe your delirious rants ?
One piece of advice for the Cryosat post that you contemplated : as the OP, back-up your statements with actual links, keep your responses to comments short and too the point, get your facts straight, and by all means, don’t write endless stories about other pet-theories you may hold.
You can thank me later.