Foreword: I had originally planned to post a story on this, but Steven Goddard of the UK Register sends word that he has already done a comparison. It mirrors much of what I would have written. There is a clear discrepancy between the two data sources. What is unclear is the cause. Is it differing measurement and tabulation methods? Or, is it some post measurement adjustment being applied. With a 30 percent difference, it would seem that the public would have difficulty determining which dataset is the truly representative one.
UPDATE: The questions have been answered, see correction below – Anthony
Arctic ice refuses to melt as ordered
Published Friday 15th August 2008 10:02 GMT – source story is here
Just a few weeks ago, predictions of Arctic ice collapse were buzzing all over the internet. Some scientists were predicting that the “North Pole may be ice-free for first time this summer”. Others predicted that the entire “polar ice cap would disappear this summer”.
The Arctic melt season is nearly done for this year. The sun is now very low above the horizon and will set for the winter at the North Pole in five weeks. And none of these dire predictions have come to pass. Yet there is, however, something odd going on with the ice data.
The National Snow and Ice Data Center (NSIDC) in Boulder, Colorado released an alarming graph on August 11, showing that Arctic ice was rapidly disappearing, back towards last year’s record minimum. Their data shows Arctic sea ice extent only 10 per cent greater than this date in 2007, and the second lowest on record. Here’s a smaller version of the graph:
The National Snow and Ice Data Center (NSIDC)’s troublesome ice graphThe problem is that this graph does not appear to be correct. Other data sources show Arctic ice having made a nice recovery this summer. NASA Marshall Space Flight Center data shows 2008 ice nearly identical to 2002, 2005 and 2006. Maps of Arctic ice extent are readily available from several sources, including the University of Illinois, which keeps a daily archive for the last 30 years. A comparison of these maps (derived from NSIDC data) below shows that Arctic ice extent was 30 per cent greater on August 11, 2008 than it was on the August 12, 2007. (2008 is a leap year, so the dates are offset by one.)
Ice at the Arctic: 2007 and 2008 snapshotsThe video below highlights the differences between those two dates. As you can see, ice has grown in nearly every direction since last summer – with a large increase in the area north of Siberia. Also note that the area around the Northwest Passage (west of Greenland) has seen a significant increase in ice. Some of the islands in the Canadian Archipelago are surrounded by more ice than they were during the summer of 1980.
The 30 per cent increase was calculated by counting pixels which contain colors representing ice. This is a conservative calculation, because of the map projection used. As the ice expands away from the pole, each new pixel represents a larger area – so the net effect is that the calculated 30 per cent increase is actually on the low side.
So how did NSIDC calculate a 10 per cent increase over 2007? Their graph appears to disagree with the maps by a factor of three (10 per cent vs. 30 per cent) – hardly a trivial discrepancy.
What melts the Arctic?
The Arctic did not experience the meltdowns forecast by NSIDC and the Norwegian Polar Year Secretariat. It didn’t even come close. Additionally, some current graphs and press releases from NSIDC seem less than conservative. There appears to be a consistent pattern of overstatement related to Arctic ice loss.
We know that Arctic summer ice extent is largely determined by variable oceanic and atmospheric currents such as the Arctic Oscillation. NASA claimed last summer that “not all the large changes seen in Arctic climate in recent years are a result of long-term trends associated with global warming”. The media tendency to knee-jerkingly blame everything on “global warming” makes for an easy story – but it is not based on solid science. ®
Bootnote
And what of the Antarctic? Down south, ice extent is well ahead of the recent average. Why isn’t NSIDC making similarly high-profile press releases about the increase in Antarctic ice over the last 30 years?
The author, Steven Goddard, is not affiliated directly or indirectly with any energy industry, nor does he have any current affiliation with any university.
NOTE OF CORRECTION FROM STEVEN GODDARD:
The senior editor at the Register has added a footnote to the article with
excerpts from Dr. Meier’s letter, and a short explanation of why my analysis
was incorrect.
To expound further – after a lot of examination of UIUC maps, I discovered
that while their 2008 maps appear golden, their 2007 maps do not agree well
with either NSIDC maps or NASA satellite imagery. NSIDC does not archive
their maps, but I found one map from August 19, 2007. I overlaid the NSIDC
map on top of the UIUC map from the same date. As you can see below, the
NSIDC ice map (white) shows considerably greater extent than the UIUC maps
(colors.) The UIUC ice sits back much further from the Canadian coast than
does the NSIDC ice. The land lines up perfectly between the maps, so it
appears possible that the UIUC ice is mapped using a different projection
than their land projection.
Click for larger image
Because the 2007 UIUC maps show less area, the increase in 2008 appears
greater. This is the crux of the problem. I am convinced that the NSIDC
data is correct and that my analysis is flawed. The technique is
theoretically correct, but the output is never better than the raw data.
Prior to writing the article, I had done quite a bit of comparison of UIUC
vs. NSIDC vs. NASA for this year. The hole in my methodology was not
performing the same analysis for last year. (The fact that NSIDC doesn’t
archive their maps of course contributed to the difficulty of that
exercise.)
My apologies to Dr. Meiers and Dr. Serreze, and NSIDC. Their analysis,
graphs and conclusions were all absolutely correct. Arctic ice is indeed
melting nearly as fast as last year, and this is indeed troubling.
– Steven Goddard
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Jeff says “Ignoring the data is a tactic that I expect from an AGW denier”
Just eyeballing these two maps
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=11&fy=2007&sm=08&sd=11&sy=2008
should convince most anyone without an agenda that the right side is quite a bit more than 10% more than the left side map. The 10% comes from data taken from this graph
http://nsidc.org/images/arcticseaicenews/20080811_Figure2.png
It needn’t be rocket science to see the inconsistency, and no need to ignore any data.
Phil. (20:12:24) :
I guess trig isn’t your strong point! (30º isn’t visible on the CT map either, although it would be if they used the projection you claim.)
The fact that a projection as claimed would include a lot more than the area shown is irrelevant. It all depends on the area included in the image and there is no point including parts of the globe which are nowhere near the arctic
Ignore the above post _ I was looking at the wrong picture
The NSIDC graph shows current NH sea ice coverage to be around 700,000 sq km or 15% greater than the same time last year, not 10%.
Jeff (21:31:35) :
As stated, the N.H. maps come from: “University of Illinois, the Cryosphere Today”. The S.H. chart, showing an increase in sea ice of more than one million square kilometers, comes from NSIDC/NASA.
If you don’t believe your eyes, go argue with them.
Honestly, some folks seem to be afflicted with what George Orwell would describe as “up is down, black is white, evil is good, and increasing global sea ice is decreasing global sea ice. Get a grip. Or at least get some facts, instead of sniping from the sidelines.
Sorry, it’s late. But it gets tiresome when the increasingly desperate AGW Bovine Fecal Purveyance Specialists flail around trying to discredit someone like Goddard or Monckton, who do their own investigation, their own research based on credible sources, and write their own articles — instead of writing an article themselves. I suspect the reason the true believers in the disappearing sea ice meme know that such any such article will quickly be torn to shreds, based on empirical evidence. The fact is, the climate always fluctuates. Naturally. The climate today is well within normal historical parameters. If anything, conditions today are quite benign.
Mr. Goddard has patiently answered each criticism in turn. More bluster won’t change that.
Why not try writing your own article instead? Ask Anthony if he would post it, and we can see how it stands up. Now that would be very interesting.
Please ignore the above post – I misread the image
Glenn,
You say:
“The significant consideration is accuracy, my friend.”
I agree that is significant, it goes without saying, which is why I do not think eyeballing is a good enough basis upon which to draw your conclusion of “the maps being inconsistent with the graph” (my eyeballing is inconsistent with yours, by the way).
If you feel comfortable will all this inconsistency, I think you are being just as irresponsible as the experts who generate it.
That’s pretty close to a straw man, Glenn. The inconsistency I feel most concerned about is that between the satellite records, since they are purportedly measuring the same things, AFAIAA, and they also show greater divergence than between other types of record.
Regardless, it appears that the Arctic melt is largely if not exclusively a result of events not related to “global warming”
That’s an interesting, and very confident, claim. Would you be able to explain to me how you quantify “largely if not exclusively”? I am well aware that wind patterns will influence the particular extent in a given season, for example, but do you have evidence to establish that the long-term trend is unrelated to warming?
But making claims about what I “happily” haven’t done or have disregarded, in the absence of evidence of that, isn’t quite honest. It’s a tactic I expect from an AGWer. Are you one, or rather do you accept the “projections” made by the various AGWers that spell doom and gloom if we don’t all stop drivin that hot rod Lincoln?
I am not a member of any church, Glenn. At present I am persuaded that the risks of AGW are high. I look forward to whatever new evidence, either way, may be forthcoming. I don’t count your eyeballing of graphs and maps to be useful evidence of anything much.
Glenn
“Just eyeballing these two maps
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=11&fy=2007&sm=08&sd=11&sy=2008
should convince most anyone without an agenda that the right side is quite a bit more than 10% more than the left side map.”
[snip – Jeff, knock off the insulting ad homs please]
Evan Jones
“What does make a difference is whether or not NSIDC is accurately reporting the data.”
And I have shown that the NSIDC esimates are reasonable [snip – thats ad hom]
The 10% comes from data taken from this graph
http://nsidc.org/images/arcticseaicenews/20080811_Figure2.png
Sigh. No, the 10% comes from your (and Goddard’s) eyeballed guesstimate of the data. The figures were published at the same time as that graph, directly alongside it, and they showed 13.5% above the previous year, a figure that is remarkably consistent with Jeff’s 14% from a count of grid cells!
dash (03:39:32) :
The NSIDC graph shows current NH sea ice coverage to be around 700,000 sq km or 15% greater than the same time last year, not 10%.
Current JAXA data (higher res than NSIDC) shows 13% ((5.839-5.166)/5.166)
Oldjim (02:52:28) :
The fact that a projection as claimed would include a lot more than the area shown is irrelevant. It all depends on the area included in the image and there is no point including parts of the globe which are nowhere near the arctic
So CT took the trouble to show the globe in perspective out to ~32ºN then couldn’t be bothered to complete it and decided to add the star background instead! I repeat that projection isn’t what Goddard thinks it is.
I incorrectly stated that I had posted the location of NSIDC’s data. That actually was in another forum. The data can be found at
ftp://sidads.colorado.edu/pub/DATASETS/seaice/polar-stereo/nasateam/
“Just eyeballing these two maps
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=11&fy=2007&sm=08&sd=11&sy=2008
should convince most anyone without an agenda that the right side is quite a bit more than 10% more than the left side map. The 10% comes from data taken from this graph”
Nobody who doesn’t have an agenda would refuse to look at the actual data.
You don’t seem to be able to comprehend that I actually COUNTED the number of grid cells with sea ice on each day and therefore I actually KNOW what the difference in areas is. My 14 percent figure is not something that “looks right” to me, it is the actual difference. There’s no other way to explain this. I’m trying to make this as simple as possible.
Smokey
“As stated, the N.H. maps come from: “University of Illinois, the Cryosphere Today”. The S.H. chart, showing an increase in sea ice of more than one million square kilometers, comes from NSIDC/NASA.
If you don’t believe your eyes, go argue with them.”
So you’re talking about the change from one year to the next? Have you looked at the long-term trend?
Where I live, we’ve already have 50 percent more rain this month than in all of August 2007. Therefore, the climate here is getting wetter, right? (unless you take into account that we have only received 60 percent of the average rainfall for the first 230 days of the year)
“Honestly, some folks seem to be afflicted with what George Orwell would describe as “up is down, black is white, evil is good, and increasing global sea ice is decreasing global sea ice. Get a grip. Or at least get some facts, instead of sniping from the sidelines.”
I have facts, unlike Mr. Goddard who mysteriously comes up with numbers without explaining how he got them.
“Sorry, it’s late. But it gets tiresome when the increasingly desperate AGW Bovine Fecal Purveyance Specialists flail around trying to discredit someone like Goddard or Monckton, who do their own investigation, their own research based on credible sources, and write their own articles — instead of writing an article themselves. I suspect the reason the true believers in the disappearing sea ice meme know that such any such article will quickly be torn to shreds, based on empirical evidence. The fact is, the climate always fluctuates. Naturally. The climate today is well within normal historical parameters. If anything, conditions today are quite benign.”
I obviously did my own research, because I obtained the actual sea ice data files and looked at the actual values rather than just saving an image from a web page. There have been numerous publications on global warming. That you aren’t aware of them is pretty startling.
“Mr. Goddard has patiently answered each criticism in turn. More bluster won’t change that.”
He hasn’t explained how he got his numbers. He hasn’t explained where he got the 10 percent difference from. He hasn’t explained why he uses JPEGs. He hasn’t explained why he doesn’t use the actual sea ice data files. Maybe he doesn’t even know that JPEGs use lossy compression, so that the color value in any particular pixel does not necessarily represent the original data value. And maybe he doesn’t understand the artifacts that can be introduced into data when it is interpolated multiple times.
“Why not try writing your own article instead? Ask Anthony if he would post it, and we can see how it stands up.”
Why would I write an article showing that NSIDC was right when NSIDC was obviously right? You [snip] have already said that you’d rather rely on your own “impression” of what the data is rather than look at the actual numbers, so printing the facts won’t change anyone’s mind.
…the disappearing sea ice meme…
It looks like we’re heading towards the second lowest summer coverage on record, contending with 2005….
…no problem, then – that must mean the world is cooling. eh?
It appears that the Northwest Passage has closed up again after only three days.
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png
Eyewitness accounts here –
http://awberrimilla.blogspot.com/2008/08/lancaster_18.html
They got out just in time. Resolute is freezing in behind them
I’m guessing that NSIDC will not make a high profile press release about this.
Someone better warn Gordon Pugh not to launch his kayak.
Pugh said, “Over recent decades, we have lost more than half the Arctic summer sea ice cover; decades ahead of predictions, showing climate change has been hugely underestimated. We must insist that our leaders take urgent action to halt climate change.”
It appears that the Northwest Passage has closed up again after only three days.
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png
Lol, now you pick the NISDC map! Here’s another view from UIUC, whose map you seemed to favour before when you wanted to make a different case –
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.some.000.png
We can all pick cherries 😉
As for a small boat getting stuck in “shortlived, thin new ice”, well, I guess that must prove the world is cooling and that AGW is a scam, eh?
By the way, Steven Goddard, have you not figured out where the Berrimilla is (whose blog you link to as an “eyewitness account” of the NW Passage supposedly closing up)? Today it’s been moving through Lancaster Sound, heading into Baffin Bay. Lancaster Sound, from which the report you link to was posted, is here:
http://en.wikipedia.org/wiki/Lancaster_Sound
Check that out against the NSIDC map you’ve linked to and you will see that it is recorded as clear blue, and is a very long way from the more marginal areas of the NW Passage!
Do some basic research, I’d suggest!
Further to my last comment in response to S Goddard’s claims of an eyewitness account to the NW passage closing up, this post shows the ice map for the area they were in on the same day that SG quotes from (i.e., yesterday) –
http://awberrimilla.blogspot.com/2008/08/baffin-bay.html
The location SG quoted from, Lancaster Sound, is to the top left. The green ‘islands’ are thick first-year ice, the triangles are icebergs, the white is described as clear water. You can see that there is no way the passage is ‘closed up’ at this point, as claimed.
In a later post from the same day, the blog is celebrating having completed the NW passage:
http://awberrimilla.blogspot.com/2008/08/pond-inlet.html
Humph – a bit of basic research there. Though maybe the notion isn’t actually to research the truth of claims that can be made?
The difference today is interesting. Note that in the 2007 version the NW passage is open.
It also seems as if the main area of the 2008 image has gained more ice percentage towards the center of the sheet than last week.
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=08&fd=18&fy=2007&sm=08&sd=18&sy=2008
icefree,
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png
Looking at that map, I’m having a difficult time seeing that “half of the ice” is gone, and I’m also having difficulty seeing how whatever is going on up there affects my life. Reading the logs of the Berrimilla, it sounds like summer in the High Arctic is bitter cold. Arctic ice obsession is yet another imagined crisis for people with empty lives.
the north west passage has been open many times in history. It’s a non event , ho hum time for bed.
As for a small boat getting stuck in “shortlived, thin new ice”, well, I guess that must prove the world is cooling and that AGW is a scam, eh?
Northern sea ice depends on too many variables other than temperatures. Precipitation, dirty snow, Arctic Oscillation weirdness (like last year), etc., etc.
For the nonce I will settle for the satellite measurements of the lower troposphere. That shows a flat (to slighly cooling) record for the past decade (or 7 years if you prefer to skip the El Nino/La Nina episodes of 1008-2000).
I would prefer accurate surface measurements but I won’t trust any of them at least until the NOAA/CRN system goes online later this year.
Steven Talbot,
Had you actually read the Bermilla blogs, you could have saved yourself quite a bit of embarrasment. The Northwest Passage is a complete route over the top of Canada which the Bermilla is currently undertaking. They are taking the shortest and fastest route across the NW Passage. What part of They got out just in time. Resolute is freezing in behind them is it that you don’t understand?
Friday’s new ice from the Canadian Ice Service
http://awberrimilla.blogspot.com/2008/08/yesterdays-new-ice.html
The purple is the new ice from the evening 13th and morning 14th, and the first I’ve seen this year.
Sunday’s new ice from the Canadian Ice Service
http://awberrimilla.blogspot.com/2008/08/lancaster-map-again.html
Purple is new ice. ‘E’,’L’ &’G’ also has new ice
Today’s NSIDC map shows the southern leg of the NW passage now blocked, which they came through a few days ago.
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png
If you have ever watched a body of water freeze, you would know that it starts out as thin ice and later gets thicker. Given that it is mid-August, someone of at least moderate intelligence might be clever enough to realize that the Arctic summer has just ended and the freeze is just beginining. They described the new ice as being The worst kind to a small boat. Tricky concept for someone who likes to shoot their mouth off before they think.