Pursuant to the previous post on The great 2007 ice crunch – it wasn’t just melt this is a follow up post for questions raised there.
By Steve Goddard
One of the favourite web sites quoted by the AGW faithful, is the University of Washington PIOMASS site – which claims to model ice volume. They show ice volume dropping off precipitously after 2006 and continuing downwards.
On their web site they include the verification graph below, which curiously stops verifying in 2007.
Obviously they have run their models post 2007, so why did they stop updating their verification? The image below gives a clue. I mapped NSIDC November extent (blue) on top of their verification graph, and something stands out like a sore thumb. Ice extent jumped back up after 2007, but their volume model didn’t.
‘
This in itself doesn’t prove anything, because it is possible that extent increased while volume decreased. (Not likely, but possible.)
Below is another one of their verification links, which actually verifies nothing because it only compares their model vs. extent. Since they undoubtedly fed the extent data as an input in to their model, it is rather bizarre that they would present this as verification evidence. It is like predicting the score of a game after it has already been played.
http://psc.apl.washington.edu/zhang/IDAO/summer2007_2008_arctic_seaice.gif
So let’s try doing some real verification. Below are the Navy thickness images from November 2007 and 2009.
Note that across the majority of the Arctic, 2009 thickness is greater than 2007. Notable exceptions being the 2007 pressure bump in the Beaufort Sea, and along the north coast of Greenland.
Conclusion: The PIOMASS models are probably not an accurate representation of current ice conditions. Most of the Arctic has increased in thickness since 2007.
The conclusions should be the focus of more research and a paper. Good work.
Michael
The Rotten Ice meme just got a bit thinner.
Although it seems likely from the images that volume has increased, I can’t really tell for sure. The top half of the circle seems to have lost quite a bit of volume, while the bottom half seems to have gained. Is there any way to quantify it?
In the top half, some large areas went from light blue to dark blue, or from dark blue to purple, both of which are in the direction of less thick. This is probably offset by gains in the bottom half, but it’s hard to tell by eyeballing it.
Is NAVO going to be a new favourite web site quoted by the AGW unfaithful ?
Too bad they don’t verify their ice thickness data.
Good luck with that.
OT
Video of Guatemala Pacaya volcano eruption
Ecuadorean volcano erupts, villagers evacuate
http://www.montrealgazette.com/technology/Ecuadorean+volcano+erupts+villagers+flee/3083797/story.html
Wow, two in one day in Central America. Is California next with perhaps an earthquake?
Another model for the advocates to claim has value that is based on conjecture/ Assumption / WAG!
Oops, I was reading it backwards. In this case, my comment is reversed: the gains are in the top half and the losses are in the bottom. Same problem, however.
I think ICESat stopped working by then – not sure! – which was the point for the (delayed) Cryosat launch.
Tchoh!, There you go with things that have actually been measured.
How on earth are you going to convince anyone with that compared to “Rent seeker magical modelled land”?
It’s like you are not even trying. 🙂
Like flipping trendlines, PIOMASS is “hiding the advance.” Circular reasoning, convenient cutoff points, have been typical of Green Gang hysterics since 1988.
Bleh. I downloaded Gimp and it can provide an exact pixel count on the images. So far what seems to work best for me (to avoid confusion) is:
Select -> by color — then click on an area of color & copy it to the clipboard.
Paste in a new file so only one region is included in a file by itself
Windows -> Dockable dialogs -> Histogram
From ICESat web site
As of October 11, 2009, Laser 2 of the Geoscience Laser Altimeter System (GLAS) onboard the ICESat satellite stopped emitting light pulses. Since this time, no new science data have been returned from the GLAS instrument.
Currently, a GLAS Anomaly Review Board has reviewed and assessed the situation and a series of attempts to restart Laser 2 has been initiated, to be followed by attempts on the other two lasers which stopped working earlier in the mission.
It might be interesting to compare the extent increase in your NSIDC extent overlay in 2008 with the last full year of data recorded by ICESat found here:
Trend in winter sea ice volume
ICESat shows an increase in first year ice in 2007 and 2008, which explains the increase in extent, although total volume held steady in 2007 and was down in 2008.
How excactly does the navy measure ice thickness directly, without using models?
Interesting analysis Steve, but myself, and the NSIDC would politely like to disagree your conclusion, when you said:
“Conclusion: The PIOMASS models are probably not an accurate representation of current ice conditions. Most of the Arctic has increased in thickness since 2007.”
In fact, that is not completely the case at all, as this study, released just last fall (2009) makes quite clear:
http://www.arctic.noaa.gov/reportcard/seaice.html
PIOMAS is not perfect, as it is only a model, and so we’ll have to wait for Cryosat-2 data to start coming in about 4-5 months to really get more precise data, but I’d wager that we’ll find that PIOMAS has been tracking the general trends very well. We really ought to have better sea ice thickness data right now, and it a travesty that we don’t…
mb says:
May 28, 2010 at 4:11 pm
How excactly does the navy measure ice thickness directly, without using models?
______________
The Navy also uses a model, and does not have direct data over the whole Arctic, and no one will until Cryosat2, and in fact the current Navy model PIPS 2.0 will soon be replaced by a “better” model, PIPS 3.0 which will be updated to use the same Los Alamos CICE modeling algorithms as PIOMAS.
@mb: PIOMAS means “Pan-Arctic Ice Ocean Modeling and Assimilation System”. When I see “assimilation” I keep thinking of The Borg “resistance is futile”. Anyways, it seems to be some sort of hybrid between models and observations. From the site here they explain:
Observations from satellites, Navy submarines, moorings, and field measurements are limited in space or time. The assimilation of observations into numerical models, currently provides one way of estimating sea ice volume changes on a continuing basis. Volume estimates using age of sea ice as a proxy for ice thickness are another useful method (see here and here). Comparisons with observations help test our understanding of sea ice conditions in the Arctic.
So basically, they try to get an idea of the big picture from a small set of samples. The ICESat measured volume by using a laser to measure the height of ice/snow, compared to sea level, then used Archimedes law to determine how much must be under water. From this the volume is determined. Unfortunately it suffered a malfunction and a replacement isn’t planned to be launched for some years, from what I’ve gathered poking around the NASA site.
Looks like most of the thicker ice, is in no danger of being driven out through the Fram Strait?
My main concern being the polar bears, of course.
First thing I notice is the scale is in 1000 km^2. A 1000 kim^2 isn’t very much relative to an icecap extending millions of km^2, especially when you think about the fact the we were coming out of a bottom and climbing to a peak temperature-wise over the period of the graph.
R Gates,
It is a travesty that anyone would call for more federal funds to study something like this at a time when we’re running a deficit of more than $0.01, not to mention > 10^11 times that amount.
Mike G says:
May 28, 2010 at 5:03 pm
R Gates,
It is a travesty that anyone would call for more federal funds to study something like this at a time when we’re running a deficit of more than $0.01, not to mention > 10^11 times that amount.
Oops, 10^14 times that amount…
R. Gates
You may have noticed that appeals to authority don’t carry much weight around here.
A bit OT, but;
The Norwegian Prime Minister has signed a deal with Indonesia;
We will pay approx 1 billion dollars to Indonesia.
Why; Indonesia has promised to cut down less rainforest.
It sounds like extortion to me. If you dont give us 1 billion, we will continue
to cut down the rain-forest…..
And how do you control it?
-“Well, you see, we cut only 1 million trees.If you hadnt paid us 1 billion,
we would have cut down 2 million trees”.
I see.
I hope they are *not* working under a government funded grant to measure the effects of ‘Climate Change’ on the Arctic ice-pack.
Way O/T, but maybe the petroleum engineers who post on here will have an answer. Watching the mesmerizing log-flame-like image of the gulf oil leak, I can’t help wondering if they haven’t thought of just hooking a high capacity multi-stage centrifugal pump up to the BOP and running sea water in at a rate that just overcomes the pressure of the oil to hold off the oil flow until they can complete the relief wells in a month or so. Such pumps are available but maybe not with a prime mover capable of being run 5000 ft down. But, such a pump could be coupled to a water driven turbine which could be powered by high volume low pressure water that could be pumped down from the surface.
“R. Gates
You may have noticed that appeals to authority don’t carry much weight around here.”
And we know ad hom’s aren’t tolerated here.
Looks like we just took away the CAGW crowd’s two best weapons. LOL!