The great 2007 ice crunch – it wasn't just melt

By Steve Goddard

CIRES photo of an Arctic ice pressure ridge

I generated an animation of 2007 sea ice thickness from the US Navy’s PIP database, and noticed something remarkable. Watch the video below, particularly inside the red square – the animation runs from May through October, 2007. The color scale on the left indicates the thickness of the ice. Watch:

At the beginning of May, ice thickness was about three metres in the center of the red square. By mid-June it was getting thicker, and by early September it was close to five metres thick! During the notorious summer of “record melt” which we have been told about ad nauseum, the ice thickness near the most affected area increased by 60%. What could have caused this? Simple – the ice was compacting to the north as it was pushed by southerly winds. It lost area – while it gained thickness.

The NSIDC news from September, 2007 touched peripherally on this idea, without actually mentioning the critical point.

The region over Siberia experienced fairly low pressure during the same time period. Winds blow clockwise around high-pressure areas and anticlockwise around low-pressure areas. The combination of high- and low-pressure areas thus fostered fairly strong winds over coastal Siberia that were partly from the south, pumping warm air into the region and also contributing to a warming Arctic. At the same time, these winds from the south acted to push ice away from the coast and into the central Arctic Ocean, further reducing ice extent in the coastal areas

Ice thickness in May 2007 was ~3 metres

Ice thickness in September, 2007 was ~5 metres

Exaggerated animation of thickness gain from compression. For effect only.

A good analogy would be shoveling the snow off your driveway. As you push the shovel forwards, the area of snow decreases – but the thickness of the snow increases in front of the shovel.

Now on to 2010. Note in the images below that ice in the Chukchi and East Siberian seas is thicker this year than it was on this date in 2007. In some locations it is as much as 5 metres thick in 2010.

May 27, 2007 Ice inside the vulnerable square (where much of the anomalous 2007 “melt” occurred) was 0.5 to 3 metres thick

May 27, 2010 Ice inside the vulnerable square is 0.5 to 5 metres thick

The AGW chameleon changes it’s colours constantly. It complains about area and extent when convenient, and about thickness when convenient. I am coming to the conclusion that the 2007 melt was more of a marketing event than a climatological event. The graph below gives a feel for just how much of a non-event it was. 2007 was 1.5 standard deviations off the 30 year extent trend, but apparently a lot of the supposedly “melted”  ice just crumpled up into more survivable thick ice.

One of the ice experts must have known this. Surprising that it took the “breathtakingly ignorant” WUWT to point it out.

ADDENDUM for clarity:

Currently the NIC uses the Polar Ice Prediction System (PIPS) version 2.0 as the basis for its “operational” short-term (24–120 h) sea ice forecasts. These forecasts are evaluated daily and amended by skilled analysts using reconnaissance data (if available), the most recent weather charts and data, and historical knowledge of the conditions in the area to provide the highest quality forecasts possible out to 120 h. Special emphasis in these forecasts is placed on the location of the ice edge and the conditions in the marginal ice zone (MIZ), as these are the most critical operational areas for marine transportation and safety.

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Pearland Aggie

If the this truth ever got out, you know the mantra will morph into CAGW causing unusual tidal gyres or air circulation patterns in the Arctic that in turn drive the ice loss. A chameleon can change his colors at the drop of a hat and doesn’t feel the worse for it!

RR Kampen

The SOTC press release on the 2007 sea ice minimum does note the effect of the wind pushing the ice away from Siberia, but emphasizes melting.
If these thickness estimates are reliable, it should be possible to calculate the one important parameter in this process: sea ice volume. Now I really wonder how September 2007 compares to other autumns in this respect!

Joe Lalonde

That is amazing!
Meaning Atmospheric pressure has an effect on ice formations.


Very nice analysis, Willis!
Now prepare for the AGW motor boaters with their ‘But-but-but-but-but …’


Breathtakingly intelligent WUWT 😉
theres NO way, they also didnt manage to figure this out..but telling people was NOT on their agenda was it?
Now, whenever I hear a single warmie statement I am so close to screaming! so much has proved to be falsified, intentional untruths aka LIES! and most is unverifiable.
australias CSIRO coastal survey advert here is just another money wasting govt con.
they want to limit tenure and be able to set a sea level they? consider unsafe and reposess land…
the CSIRO climate warming fightback..15 million when we are in debt? for a fictitous issue?
sooner KRudd and W(r)ong and garrotte and R guano are OUT the better for us all!

As a long time snow shoveler it’s very clear that matter doesn’t just magically disappear otherwise snow shoveling would be a lot easier to do.
Wow, it’s nice to find the evidence of this reduction of area without it all being a reduction in volume. I wonder how this might apply to other years?
How can the ice volume be computed? How accurate would such computations be? How do we know?
How were the ice depth measurements obtained? Satellite? Which? What is the “chain of custody” of that data?
Depending on how much ice volume crumpled up into the pile as opposed to melting this could invalidate the use of ice area alone as an indicator of how much ice there is in the arctic.
Oh, “open chain of custody” is an appropriate term and standard to use for all scientific data that is collected, processed (including all manipulations), and used in any conclusions presented to any politicians or to the public. Data can’t be or shouldn’t be trusted unless it has a high integrity in it’s “open chain of custody” that can be shown to any who ask for it.

t . f . p .

[snip – I’ve warned you before about constantly posting under different names, Aka “Dick Chambers” aka “The Ford Prefect” pick one and stick with it, or don’t post here again. I’m not interested in your games. -Anthony]

Olaf Koenders

It’s been said before – never let the truth get in the way of a good story.
CAGWists are running scared and trying every avenue to justify their position. Notably, the propaganda goes into ridiculous overdrive to create alarmism, which promotes attention. “Global Warming will cause more.. umm.. EVERYTHING!” they spout in ever increasing wails for lazy funding and a slack job to go to in the morning. It’s far more difficult for us Climate Realists to have our voice heard over the whining din, however the real truth shall never be silenced.


Curiously (or not), this corresponds to our friend Vuk graph of GMF:
Where Siberia decreased temperatures while Hudson Bay increased. Then we can have an idea what moves winds and climate.


I am coming to the conclusion that the 2007 melt was more of a marketing event than a climatological event
What AGWrs´Marketing managing will be planning for this year, as a preparation to achieve their goal of Global Socialist Governance in Cancun?

Steve in SC

Better ice be 0 inches thick than 1 mile + thick.
Ice comes and Ice goes only where the wind blows.
The hot earthers are once again making much ado about nothing.
Damn drama queens.

Steve in SC

In the interesting of fiscal responsibility, we need to cut their funding to zero as they are contributing to the burning of the federal treasury.

Steve in SC

Should be interest in lieu of interesting.
Need an edit feature badly for those of us with alternatively slow and fast fingers.


Carbon burp from ocean ended last ice age, very nice article:
The paper:
So, the earth has cycles and changes and it isn’t all our fault? What a surprise!

Steven Hill

Nice work…….


It would be very interesting to see the internal emails about this. They had to know, and therefore it can be inferred that the false, alarming impression was intentionally made. This is a clear and consistent pattern. How can so many supposedly smart people be so willing to go along with this stuff? More marketing the politics than analyzing the data.

An historic parallel….
As again real scientists prove that the earth, is indeed, not flat.


Well thank goodness that the science was settled before you discovered this . . . otherwise the science wouldn’t be settled.
No wait, that can’t be right . . . . that logic doesn’t hide any declines.
This is like the ACE readings for Hurricanes.
Area of ice coverage is like the count of named storms.
Mass of ice is like the amount of energy of the named.


Huh. That is interesting. I did not realize you could get that significant an increase in thickness over a significant area in size *during* melt season.
Extent has always been an imperfect metric –but it is what we have for a long enough period and great enuf granularity (daily) to be worthwhile saying anything about in historical terms (and even that, just barely –I’d much prefer we had it back to 1945 or so). Yes, volume would be better –and when we have 20 years of daily (or even weekly) volume data that’ll be worth saying something about. Even the snapshots from ICECAP did not have enough granularity to be all that useful for historical comparison even in the handful of years it operated.


So we should ignore ice extent, and instead emphasize ice volume?

Jean Demesure

Inconvenient “rotten ice” !

Dusty Rhodes

Just a thought, but it seems to me that if thickness can be measured and area can be measured then using volume as the measure for comparison would resolve the argument.


Steve, with thickness and area data it’s a simple calculation to get ice volume and that would be an interesting metric to compare over years.


Last night on “As it happens” (A CBC radio program) they interviewed the new climate person at the UN. She described Canada’s contributions to climate change as “not having reached their Kyoto commitment and their new targets are even lower.” Maybe Harper is not as bad as I usually find him.
I also contacted our Auditor General as well as Environment Canada to ask them how much of our tax dollars were being spent on carbon dioxide reduction and other AGW items. The AG replied that it was not an item that it verified and EC said that they had no budget for AGW so had spent no money on that item.
I will continue to ferret out how many of our (Canadian) tax dollars are being wasted on this “model” situation.


So what’s your take on the current ‘melt’ we hear so much about? Do we have evidence of persistence of the thickened and hence more survivable ice over the subsequent three years? More importantly, has ice volume changed substantially and if so in what direction?


It’s not just the ice that was thick…..;-)


Multiple factors including winds and currents contributed to the 2007 Arctic ice minimum — as they do every year. Very detailed analyses have been published in many scientific papers and widely discussed at meetings. NSIDC’s report from October 1 2007 took a reasonable first look:
“One factor that contributed to this fall’s extreme decline was that the ice was entering the melt season in an already weakened state. NSIDC Research Scientist Julienne Stroeve said, ‘The spring of 2007 started out with less ice than normal, as well as thinner ice. Thinner ice takes less energy to melt than thicker ice, so the stage was set for low levels of sea ice this summer.’
Another factor that conspired to accelerate the ice loss this summer was an unusual atmospheric pattern, with persistent high atmospheric pressures over the central Arctic Ocean and lower pressures over Siberia. The scientists noted that skies were fairly clear under the high-pressure cell, promoting strong melt. At the same time, the pattern of winds pumped warm air into the region. While the warm winds fostered further melt, they also helped push ice away from the Siberian shore. NSIDC Research Scientist Walt Meier said, ‘While the decline of the ice started out fairly slowly in spring and early summer, it accelerated rapidly in July. By mid-August, we had already shattered all previous records for ice extent.'”

Interesting, perhaps an answer would be to report ice as a volume as opposed to surface area it would take some of that ambiguity out of the reporting, of course reporting volume as opposed to areas probably violates some rule somewhere

Steve Keohane

Steve, thanks for staying on top of this. If I remember correctly, NASA did issue a statement in 2008? that the ice had not melted in the minimum of 2007, rather it was compacted by unusual currents and winds. This didn’t apparently sink in for the CAGW crowd.
On another note, I made a joke a few weeks back about the dearth of ticks. Seriously, after nearly forty years in Colorado, I have seen 2-4 ticks per week until things dry out in June. In 2009 I saw 3-4 ticks total. This year none, and I’ve been clearing brush for weeks and should see a higher than normal incidence. It seems odd to me.

John G

Data from the National Oceanic and Atmospheric Administration, a United States agency, show that globally, this winter was the fifth warmest in history. Just saying. Please no more igloos in DC or dumb crap like that.

Ed Caryl

Do you have the computer horsepower to compute the ice volume?

I could make an estimate of the ice volume by counting and numerically integrating pixels, but it would be nice to have access to the original data which the maps were derived from.


It’s like the “melting glaciers” meme. They are vanishing, in those areas where they aren’t bulking up, because of a lack of precipitation not because of heat. Unfortunately the warmistas can’t tell us how the CO2 thingy is causing that so they give the melting rather than flowing downhill as they always do, and have little or no replenishment.
Here in Zimbabwe the ability to grow crops was destroyed for political reasons but my government wants “Global Warming Money” to compensate for the crop failures. Rain, temperature, soil and crop types are all as they ever were within normal variations but we love the thought of the evil west giving us money to bail us out of our own ignorance. Sounds like Global Socialism to me.

Steve Keohane
I think we heard that the ice had been pushed and/or possibly compacted horizontally, but I don’t remember hearing any press releases discussing thickening. My take at the time was that the ice had been pushed out into the Atlantic where it melted.

Plenty of ways to cook data. that’s why AGW is the perfect lie to tell to lay people.


What NASA said in 2007 was:

“A new NASA-led study found a 23-percent loss in the extent of the Arctic’s thick, year-round sea ice cover during the past two winters. This drastic reduction of perennial winter sea ice is the primary cause of this summer’s fastest-ever sea ice retreat on record and subsequent smallest-ever extent of total Arctic coverage.
The scientists observed less perennial ice cover in March 2007 than ever before, with the thick ice confined to the Arctic Ocean north of Canada. “
I want to know what is the definiton of “thick”? 1m, 2m, 3m, 4m, or 5m?


I was under the impression that wind-pushed ice stacked up to become thick, did not melt through, and this was how ice became multi-year ice.
I am pretty sure that the Arctic is not going to be ice free in the summer during any of our lifetimes. It is too cold, and the sun isn’t out long enough to melt it all before it starts freezing again.


You guys posted this not too long ago:
“Of course our friends will argue that extent and area don’t matter now, that only volume and ice quality (the rotten ice meme) matters.”
But now you agree that we should focus on ice volume?

Retired Engineer

Olaf Koenders says:
“Global Warming will cause more.. umm.. EVERYTHING!”
Global Warming causes everything?
Quote of the week!

Don B

As is true at sometime every year (since 1979), global sea ice area is above the 30 year average.

Pamela Gray

Gee. I never would’ve figured this out. I’se jess a tater couch hick from Orgun, hyuck hyuck.


“Data from the National Oceanic and Atmospheric Administration, a United States agency, show that globally, this winter was the fifth warmest in history”
That’s because it gets warmer every year in places where they don’t have thermometers. The cure for global warming is more thermometers in remote places. It’s a kind of voodoo.

tim c

All factors count and make it seem more like a “weather event” than any real change.

Pamela Gray

For those posters who are opening their mouths and proving something, I’ve been talking about ice compaction since day one. It is a simple mind experiment involving ice behavior, surface wind, and the nearly landlocked bowl we call the Arctic. Hell, kids playing cotton ball airhocky can figure this out.

Kevin Kilty

That is a great animation, Mr. Goddard. In the classical Stefan problem — heat removed from the surface of an ice sheet with constant lower-boundary temperature, the increase of thickness goes as square-root of time. To double the thickness of first year ice takes four years. Here the doubling took mere weeks.


I greatly appreciate this info. As I recall, when ice extent began to increase post-2007, Alarmist switched over from “extent” to saying that the “volume” was less (and also that the ice was “rotten.”)
I was suspicious, because I couldn’t see how they were computing “volume.”
I think it is hard to compute the volume of pressure ridges. If they show at all, in the various maps of the arctic, they only appear as spiderweb-thin lines.
In actual fact they are large enough to cause people traveling over the ice to avoid them. The photo you use doesn’t do them justice. Please recall that the first Catlin expedition avoided them, prefering to travel down refrozen “leads,” which were nice and flat and smooth (and easier to drill sample-holes through.)
Pressure ridges can be jumbles of ice twenty feet high, (perhaps as seen in the far distance of the photo you use to illustrate a pressure ridge.) If nine tenths of an iceburg is under water, the unseen part of a pressure ridge extends downwards one-hundred-eighty feet (and is a hazard for subs.) The total thickness would be two hundred feet, or roughly 65 meters.
There is never any mention of ice 65 meters thick in Alarmist descriptions of the arctic.
While it is true these thick areas of pressure-ridge ice would be like hairs, on any map of total ice extent, I feel they make computing “volume” all the more difficult.


Steve said: The graph below gives a feel for just how much of a non-event it was. 2007 was 1.5 standard deviations off the 30 year extent trend, but apparently a lot of the supposedly “melted” ice just crumpled up into more survivable thick ice.
I’m sorry Steve, but I don’t follow what you are saying about the 2007 melt being a non-event. The graph shows a drop in September ice extent from 6 t0 4 in 2006-2007, which is the same amount in one year that your trend line declines ( 8 to 6) over the entire 30-year period, and while you say “a lot of the supposedly melted ice just crumpled into more survivable thick ice” you don’t quantify what you mean by a lot. It doesn’t look like a lot to me.
But the most serious flaw in the analysis may be assuming ice didn’t crumple up during previous year’s melts, if that’s what you are implying. If it did crumple up, then that is reflected in your chart on September ice extent for the entire 1978-2009 period, and therefore the drop in ice extent from 6 to 4 in 2006-2007 is a measure of change which takes the crumpling into account.


I notice that the scale only goes up to 5m. It’s likely that some of the ice was/is even thicker than that.


Very nice analysis, Steve! Thank you for informing us WUWT readers.
On the other hand, for those who has it as a daily job to analyze these things, I would say that it would be expected to notice this. And when noticed, it is incredibly sneaky to hide it. Shameful, it is. So there it is; Either incredibly stupid, or incredibly sneaky.
Will be interesting to see the comments from the GAIA believers.


At the beginning of May, ice thickness was about three metres in the center of the red square. By mid-June it was getting thicker, and by early September it was close to five metres thick!
So the model results that you present show a patch of thick ice in October, here’s what it looked like in Jan. 2008 when there was a ‘massive breakup’ of the Beaufort Ice and then washed away.
You could try looking here and see what actually happened (note that the ice moved out from the N Canadian Ice pack and fragments, not compressed):