Discrepancies In Sea Ice Measurements

It could simply be differential melt of the two populations of ice. Imagine thicker older ice which melts more slowly resulting in a slow reduction in the > 30% coverage areas, whereas at the margins the 15% < x < 30% ice population is made up of thinner, younger ice. Late season, one could easily imagine differences between these populations.

The JAXA numbers also appear to be more inline with the DMI numbers (noting their different cutoffs of 15% vs 30%).
I too, noticed the NSIDC trend line was diverging from the JAXA trend line several days ago.
I don’t think the following is in your sea ice links, but I could be wrong;
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_concentration_hires.png
taken from this NSIDC link;
http://nsidc.org/data/seaice_index/
It shows the daily concentration image (NOTE: it shows zero concentration but does not show 0% < concentration < 15% data, in other words, it is their 15%+ concentration map).

The warmist could not accept any NH ice even close to 2005-2006 the whole thing will crash that is why NSCDC cannot accept DMI graph.

The NSIDC maps show 7.5% more ice in 2010 than 2007, but their graph shows less than 3% difference.
Another case of ‘rotten ice?’
Or maybe it’s just ice termite-ridden?
:o)

Nansen does not agree with NSIDC either and uses 15%.
http://arctic-roos.org/observations/satellite-data/sea-ice/ice-area-and-extent-in-arctic

Steve: you have a site for digital NSIDC data !
Could you share it ? ? Please ?

mikelorrey says:
August 4, 2010 at 3:30 pm
The DMI Graph of 80N is close to freezing, and is staying put.
The Aug3 NOAA polecam showed frozen pond and some new snow.
NOAA/NSIDC and it’s subsidiaries are digging themselves a hole.
Congress will be less than thrilled about that.
Ships are not the only things capable of getting stuck in the pack ice.

Charles Wilson
I got the NSIDC data from Julienne’s post yesterday. Sorry.

Joe Bastardi said around mid July 2010:
“The coming drop of global temperatures over the next year, to levels not seen since the 1990s, should put to an end to the AGW argument for good except for the most radical elements…………… Once the Atlantic, still warm, goes into its cool stage in 10-15 years, global temps will fall even further, back to where they were in the 1970s.
The recovery of the northern ice caps will become more obvious in a two-steps-up, one-step-back fashion, but the Southern Hemisphere ice will retreat back to near normal. Overall global ice is right on top of normal and has had no change in the past 30 years. ”
http://www.accuweather.com/world-bastardi-europe-blog.asp?partner=accuweather
http://pgosselin.wordpress.com/2010/07/17/will-2010-stay-hot-and-joe-bastardi-return-to-1970s-cold/

Worry not Steve, 2010 is showing no great change from the general downtrend over the past few years. These little differences may be of interest if you’re looking a the variations of sea ice within a specific week, month, or season, but these little variations and differences are insignificant when talking about bigger picture of climate. 2010 falls right in line with the general downtrend in year-to-year Arctic sea ice that we’ve been seeing for several decades as well as the accelerated downtrend we started seeing in 2007. If this trend is going to reverse, as the AGW skeptics would like to contend, then I surely would like to know:
1) By what physical known mechanism will this reversal take place (i.e. what natural cycle will be swinging back the other way) GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.
2) What is the anticipated year that we will see this uptrend begin?
3) Will this be a “spiral” up, or should we anticipate a bee-line back to 8 million sq. km. summer minimums?

Haven’t they learned that we’re watching this stuff daily and they cannot get away with fudging ANYTHING?

We are not really talking about “sea ice measurements”. We are talking about sea ice estimates. Otherwise, the divergences could not possibly be so large.

R Gates,
We have already seen a reversal from the southerly winds which caused the 2007 low. What else are you looking for?

Some of you guys seriously think that there is fraud going on here?
~shakes head in wonder and despair~

What the ice graphs are telling me is that the ice is more intact and consolidated this year. 15% extent is down but 30% extent is up. Ice area is leveling off nicely. It just means that we have about as much ice now as we had in 2009 but that it is more consolidated and wasn’t broken up so much by storms/wind/wave as much as previous years.
That temperature graphic is already showing an area below 0C near the pole. The ice area should begin to level out now. Iceland is picking up 6.5 minutes of darkness per day now and the night is already nearly 6.5 hours from sunset to sunrise.
So far it looks like we are sitting good for a really solid icepack next year.

Did phytoplankton take over?

David Gould says:
August 4, 2010 at 5:29 pm
“Some of you guys seriously think that there is fraud going on here?
~shakes head in wonder and despair~”
It isn’t difficult to understand. Many here are so used to seeing intentionally manipulated data in regards to the climate, that the response is expected. In this particular instance, I’m willing to give the benefit of the doubt. But even knowing they do measure 2 different things, the discrepancy shouldn’t be that great when measuring the difference between now and 2007. Given the NSIDC’s graph and map don’t match, I’d say the grapher and the mapper are not on the same page. Oddly, though just by eyeballing, even if the graph reflected the map’s ice area, I think the year to year comparison would still be too great of a difference to reflect reality. But that’s just eyeballing.

Ed Reid says:
August 4, 2010 at 5:05 pm
We are not really talking about “sea ice measurements”. We are talking about sea ice estimates. Otherwise, the divergences could not possibly be so large.
They are measurements taken from satellite. That is why it’s odd they aren’t close to the same.
mikelorrey made an interesting comment that “NSIDC counts meltwater pools on top of ice as open water, I’ll bet” which could be the explanation. But I don’t know for sure.

stevengoddard says:
August 4, 2010 at 5:28 pm
Gail
The satellite photo you linked was from July 5.
______________________________________________
Weird.
If you click on the date on the right hand corner you get a calender and can up date. I am surprised the link was not update too.
HMMmmm I tried it again and the link still did not update to the map I was actually looking at – July 31 2010
I figured it out. Try this: http://ice-map.appspot.com/?map=Arc&sat=aqa&lvl=6&lat=74.571668&lon=-139.120367&yir=2010&day=212

David Gould says: fraud? ~shakes head in wonder and despair~
August 4, 2010 at 5:29 pm
I have the same feeling. Many folks seem to think that someone is in charge. Who? Anyway, those calling fraud ought to spend a few days writing out a very detailed plan as to how they would accomplish what these agencies and their people are trying to do. Start with the equipment you will need. Then the people to do it. Then begin with what you would do tomorrow morning, and tomorrow afternoon. Keep repeating. Check back in a couple of weeks and let the rest of us know how you are doing.

Perhaps this is a case of ‘noble cause corruption’ made manifest or just an honest difference of opinion. For a real comparison with 2007 data, it is necessary to demonstrate that they are now using the very same measurement criteria that they used to collect that 2007 data.

The NSIDC maps show 7.5% more ice in 2010 than 2007, but their graph shows less than 3% difference.
NSIDC has to handle the polar stereographic projection correctly, unlike bloggers that just eyeball an image or count pixels. I’d be very surprised if someone proved that the National Snow and Ice Data Center was doing this incorrectly, but you’re welcome to try and surprise me (and NSIDC).
Polar stereographic projections are conformal (preserves angles), but not isometric (preserves distances) or area-preserving.
http://nsidc.org/data/nsidc-0051.html

John F. Hultquist says:
August 4, 2010 at 6:57 pm
David Gould says: fraud? ~shakes head in wonder and despair~
August 4, 2010 at 5:29 pm
I have the same feeling
===============================
Are you the same person? You asked for a detailed plan, however, and here it is:
1 – Get computer and turn on
2 – All I need is me
3 – Adjust data to fit model
4 – Repeat until sky falls in
Just-ice will be done!

Rhys Jaggar says:
August 4, 2010 at 7:30 pm
The only useful plot is arctic plus antarctic anyway.
There’s clearly something to do with tilt or the like which means that when the antarctic is at historic highs the arctic is low. Presumably the opposite is also true?
This should help:
http://www.robertb.darkhorizons.org/seaice.anomaly.Ant_arctic.jpg
Apparently, the Arctic Sea Ice was higher than the Antarctic until they crossed paths in mid 1993.
Right about the time the Previous Alarmists were stung by the recovery of the Antarctic, and the Coming Ice Age of the 1970’s based on the Arctic Sea Ice growth.

Günther Kirschbaum says:
August 4, 2010 at 4:06 pm
“If weather conditions turn into those 2007 experienced there is a very good chance of a new minimum extent record. And that after 5 weeks of weather conditions that are adverse to ice melting, with all those clouds, lower temperatures and the Beaufort Gyre and Transpolar Drift Stream stalling completely (reversing even).
Despite those adverse conditions during the most important phase of the melting season, the ice looks in a terrible state and could reach a new record minimum extent, if weather conditions switch back again. Amazing, really.
If the Arctic shows another ‘recovery’, it will be because very, very thin ice managed to get spread out enough and survive long enough for the cold air to come and let the sea water between the floes freeze up again.
Come in, CryoSat-2. We need your data.”
So in other words Gunther, regardless of the result Global warming is to blame. ROFL. I can picture us entering another ice age and Gunther will still be around trying to claim that AGW has somehow brought it about.
All signs are that we are now heading into a strong La Nina event, something not seen for over a decade. Will this cause the same sort of step down in global temp anomalies (UAH satellite data) as the step up we saw following the 98 el-nino. If it does I seriously doubt you will see a continuing trend of reduced summer minimum extents in the Arctic.
Little wonder the frantic efforts by AGW advocates to get their money making schemes in place before things start to cool and people realise what type of a scam is being run.

James Sexton,
You say that ‘even if they are measuring different things, the discrepancy should not be that great’. On what basis do you make that claim?
As to the claims of other manipulation and adjustment – basically, claims of some vast conspiracy to acheive global dominance via the stealing of underpants – they are simply further examples of where conspiracy theory thinking leads one.
Scrub conspiracy theory thinking from your minds, people. The world may make less sense to you initially. But your thinking will be the better for it. 🙂

Walt Meier says:
August 4, 2010 at 8:31 pm
………and when there is good overall agreement – as in the long-term decline in Arctic sea ice extent – high confidence in the results.”
Fair enough Walt, but questions are now being asked with regards the implications of whats happened since the 1997 record melt which took out a lot of multi-year ice.
If you argue theres been no recovery, you can also argue that there is no evidence of a further decline to support the death spiral argument. If anything was going to sound the death knell for Arctic Ice, surely it should have been the 2007 melt along with what were being told are record temps in 2010.
And yet here we are in August and every possible measuring indicator shows a greater extent than 2007, some showing considerable more ice than 2007. From an Artic Ice death spiral viewpoint this hardly fits.
Incidentally there is every possiblity that the 2010 minimum extent (based on JAXA data) will be within a few hundred thousand sq km of the 2002 result.

Thanks for that very straight forward explaintion on possible difference in Arctic sea ice extent estimates.
I do have a question/request, if you would be so kind.
Is it possible to obtain the DAILY Arctic sea ice area/extent digital data for the 2008, 2009, and 2010 calendar years?
And if so, who should I contact for a data request of this type, or conversely where on the WWW is this data located (website, FTP, etceteras).
NOTE: I’m not interested in the gridded data, just the daily time series of single valued Arctic sea ice area/concentration.
TIA

R. Gates says:
August 4, 2010 at 4:30 pm
Worry not Steve, 2010 is showing no great change from the general downtrend over the past few years. These little differences may be of interest if you’re looking a the variations of sea ice within a specific week, month, or season, but these little variations and differences are insignificant when talking about bigger picture of climate. 2010 falls right in line with the general downtrend in year-to-year Arctic sea ice that we’ve been seeing for several decades as well as the accelerated downtrend we started seeing in 2007. If this trend is going to reverse, as the AGW skeptics would like to contend, then I surely would like to know:
1) By what physical known mechanism will this reversal take place (i.e. what natural cycle will be swinging back the other way) GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.
2) What is the anticipated year that we will see this uptrend begin?
3) Will this be a “spiral” up, or should we anticipate a bee-line back to 8 million sq. km. summer minimums?
=====================================
Burden of proof is on you there. Nice try to introduce a roan fish (red herring) but it will not work anymore.
By what physical known mechanism will you ever be able to prove anything?
You can’t. You know just enough to be somewhat effective, but not enough to make the grade
I do appreciate though….how you finally (after months and months of self-congratualtory misinformation) have finally started using the term General Circulation Models….as opposed to Anthropogenic Global Warming Models….but I digress.
All the cream rises to the surface…eventually. But that still does not explain why you still believe in your religion.
Hey….I guess homo sapiens are steeped in mythology….sometimes irreparably so.
Chris
Norfolk, VA, USA

stevengoddard says:
August 4, 2010 at 5:21 pm
R Gates,
We have already seen a reversal from the southerly winds which caused the 2007 low. What else are you looking for?
_______
So your contention is that the entire last several decades of slowly declining summer Arctic sea ice, with an accleration of that decline beginning in 2007 is all related to “southerly winds”? And is it your contention also then that these winds are now going to blow from some other direction, and that will reverse the trend, and so all the GCM’s just have it wrong? I just want to understand the basis for the belief (so far not seen in the data) that the Arctic sea ice is about the show a “recovery spiral”? I would think then that we will start seeing some positive Arctic sea ice anomalies at some point, as the recovery takes hold.
And one final question…since we are also seeing an increasingly well documented slow warming and melting of permafrost across the Arctic and subarctic regions, are these “southerly winds” also blowing deep underground to move the permafrost around and warm it?
Of course, I don’t believe it was only “southerly winds” that has caused the decades long slow decline of Arctic sea ice, but a longer term slow rise in global temps, amplified in the Arctic. Changes in the winds are one of several effects from changes in temperatures in the troposphere, as for example, we see with the Arctic Dipole Anomaly.
But one final question

James Allison says:
August 4, 2010 at 5:52 pm
R. Gates says:
August 4, 2010 at 4:30 pm
I believe the onus is on you to prove your idea that the recently observed slow decline in Arctic ice is due to AGW or human produced CO2 or whatever you are want to call it these days. You also need to provide proof to viewers here why the observed slow increase in Antarctic ice is also due to AGW.
Put up the proof or stop the tedious “caused by AGW” you continually post on this website
_______________
James, I don’t have any “onus on me” to prove anything. I did not make up the GCM’s that forcast the slow decline of Arctic sea ice due to AGW. Far smarter people than me get paid to do that. I provide plenty of links to scientific studies when I’m trying to make a specific point. The AGW hypothesis has forecast for quite some time the slow decline in sea ice with specific reasons why polar amplification of general global warming will be seen. The fact that this appears to be happening doesn’t prove that the AGW hypothesis is correct, as the causes could certainly be Steve’s “southerly winds”. But the other evidence (also predicted by AGW models) such as stratospheric cooling, ocean acidification, permafrost melt, etc. starts to lean strongly toward the AGW hypothesis likely being correct to some degree. I’ll leave it up to the Ph.D’s, such as Julienne and Walt to have the “onus on them” to discover linkages and the details of exactly how AGW will be changing the Arctic environment..
Also, in regards to the Antarctic, again, we’ve discussed this so many times here on WUWT that it really gets tedious everytime someone (usually a skeptic) trys to point at its small year-to-year positive anomaly and expect that fact to somehow refute AGW. I suggest you google it and find all the links to the science for yourself, but I’ll throw out one for free:
http://psc.apl.washington.edu/zhang/Pubs/Zhang_Antarctic_20-11-2515.pdf

@R. Gates August 4, 2010 at 4:30 pm
“GCM’s are predicting an eventual ice free summer Arctic, so what do the skeptics know that multiple GCM’s have left out. I’m sure they’d like to know this secret information.”
I agree we could well have an ice free summer Arctic. Eventually.
No doubt it has happened many times before and may well happen again. Not holding my breath it will be in my life time.
And if the summer Arctic is ice free, that proves what, exactly?
If the Arctic north of the Shetland Islands was frozen solid one future winter, would you accept that the whole AGW hypothesis is nonsense? I doubt it, you’d be on here with some kind of weird explanation and be saying that actually, Arctic ice was only one tiny piece in a much bigger jigsaw. After all, the AGW hypothesis puts the bacon on most warmists’ table. Possibly yours too.
What “multiple GCM’s have left out”? Well, there is skill and integrity, for a start.

John H.H.;
1. Introduce “deliberate error”.
2. Pay big bux for supporting evidence and obfuscatory publications and reports.
3. Declare consensus.
4. Prevent dissemination of data tending to falsify consensus.
5. Use 3 to demand global taxes to continue and accelerate 2.
Etc.

When the real variable being measured has a high derivative, as it does now, it’s not surprising that different sampling techniques give different results.
Why not show the discrepancies on past years to see if this issue is systematic to the measuring techniques?

thank you, Cassandra King

mikelorrey: August 4, 2010 at 3:30 pm
NSIDC counts meltwater pools on top of ice as open water, I’ll bet…DMI, on the other hand, only seems to have an agenda of measuring the ice, even if it is submerged under meltwater pools.
Swell. Now in addition to new ice, multi-year ice, rotten ice, flippy-floppy ice, thick ice, and thin ice, now we’re going to have to distinguish between “wet ice” and “dry ice” (or “non-wet ice,” since we’re not concerned with frozen CO2)…

For anyone trying to understand cycles I very much recommend Joe Bastardi’s video on sea ice. He clearly shows the connection the Pacific decadal oscillation, which as it has reverted you can see the ice coming back.
I’m surprised the PDO has been dismissed by some people as not being the cause, when it is clearly in synch. with the ice recovery.
This has been posited by Don Easterbrook, so I would suggest anyone who wants a scientific viewpoint to visit his website, i.e. that a delay before the recovery kicks in is to be expected. This does fit in with historical observations of the past.

Hmmm….DMI’s site has gone back to showing Tuesday’s ice graphic. I saw Wednesday’s yesterday and would normally be looking at today’s at this time of the morning in the UK (0945 BST).
WUWT?

As you know, in late summer when most of the ice is north of 75N, the pixels are reasonably close to equal area.
By my calculation a pixel at 75N will have cos(15°), which is 96.6 % of the size of one at 90°. So it ain’t that which is causing most of the discrepancy.
BTW: every time I hear the “the AGW scientists are really smart” defence for a discrepancy, I tend to remind myself of the track record of really smart economists, such as the Nobel prizewinners at Long Term Capital Management. Which does not inspire confidence!

Excerpt from: R. Gates on August 4, 2010 at 10:27 pm

I did not make up the GCM’s that forcast the slow decline of Arctic sea ice due to AGW. Far smarter people than me get paid to do that.

Far smarter people than you get paid to make up Global Climate Models that forecast the slow decline of Arctic sea ice due to Anthropogenic Global Warming.
Then subsequently declines in Arctic sea ice get cited as evidence of Anthropogenic Global Warming, since obviously the model was correct as declines were noted.
Meanwhile evidence that runs contrary to the models is routinely discounted and discredited as obviously in error since the models have shown themselves to be correct, namely a lack of statistically-significant warming, Arctic sea ice that is not continually declining every year, evidence showing previous declines in Arctic sea ice thus any current one is not unprecedented, etc, etc.
And that’s not even getting into why a Global Climate Model would specifically have to consider any Global Warming to be Anthropogenic in origin to forecast a decline in Arctic sea ice.
Obviously these people must be very smart indeed, since they are able to keep getting paid for making up this stuff…

This is not so much a conspiracy theory as a bubble. Scientific funding appears to be proportional to the scale of the crisis predicted. Institutions inflate to fill the budget and then are no longer able to question the science. Scientists who do question it are unlikely to be viewed favourably by their employers – because the end result of them being correct is a cut in budget. A lot of the “science” you see on this stuff looks like it was written by a re-titled environmental activist. Cap and trade has made vested interests of banks (trading profits) and industrial groups that make a fat margin on this stuff. When was the last time you saw an environmental policy analysed on cost-effectiveness in the MSM? And this is supposed to be the most expensive problem mankind has ever faced.

David Gould says:
August 4, 2010 at 8:40 pm
“There is a simple maxim: if you have to choose between explanations for something and one of them is conspiracy and the other is error, you should be choosing error every time. Conspiracy theory thinking is anti-reason.”
Your maxim is drivel. The supposedly rational “never infer malice over incompetence” notion is one widely promoted by the malicious – especially socialists, greens, authoritarian “liberals”, and other ideologues. It’s an effective propaganda cover for deliberate dishonesty. Sometimes the simplest explanation for something is that it’s a lie. If a burglar claims the door fell open when he brushed into it, he’s probably not telling the truth. If a second-hand car dealer tells you that the rust is nothing to worry about, he’s not being ignorant or incompetent; he’s trying to con you into buying the car at as inflated a price as he can get away with. If a politican or political spokesman tells you something that seems erroneous, he’s probably promulgating a porky; that’s his job. Even if it seems correct, the chances are high that you’re being subtly deceived. That’s how they get where they are – not by being stupid but by being good at lying. They can even lie to themselves, pretending that the “end justified the means”and that their selfish interests naturally align with the common good; they may even have “good intentions”, of the sort that pave the road to Hell. But they’re not thick. They’re scumbags, not idiots. Their errors are culpable errors.
As for conspiracies, dishonest people engage in them all the time. Refusal to accept the existence of conspiracies is neither reasonable nor prudent. There are millions of conspiracies, some with similar goals, some with differing goals, some with rivalrous goals. Whenever two or more people cooperate in deceiving another, there is a conspiracy. It doesn’t take a secret society of Illuminati. Conspiracy is the ground state of mankind.

Its all so 2008
http://www.theregister.co.uk/2008/08/15/goddard_arctic_ice_mystery/

Günther Kirschbaum says:
August 4, 2010 at 3:56 pm
“A chunk of old ice has broken away from the main pack and come to rest along the north coast of Alaska, east of Point Barrow, where it has begun to melt in the warm shallow shelf waters.”
Hmmmmmm……makes me think…
All we need is to stop sending out these ice-breakers filled up with AGW researchers , and all will be normal?

Some of you suggest we are looking at conspiracies, but in actuality I’m sure none of us really want a conspiracy when it comes to tracking and watching what the Arctic ice is doing. Besides noticing this discrepency that Steve finally brought to light in this post, because it became even more pronounced in this mornings NSIDC sea ice update. I’ve been waiting and hoping that igloo.atmos.uiuc.edu would get their sea ice comparison page up and working again. I have been using that page for over three years and it seems weird that soon after WUWT that put a link to that page on it’s new Sea Ice Monitering page it went down.
I hate thinking it’s a way to keep us from easily comparing 2007 levels to what’s happening in 2010, but to me it’s a bit suspicious.

dorlomin
In 2008, the problem turned out to be with the UIUC maps, rather than with NSIDC.
This time, it looks like a problem is with the NSIDC graph.

I was wondering what the narrative would be if Steve’s prediction of 5.5 million K^2 turned out to be wrong.
The narrative appears to be taking shape: “I wasn’t wrong… the data is wrong!!!”
I just didn’t Steve’s confidence in his prediction to melt so soon.

RE David Gould: (August 4, 2010 at 8:40 pm) “There is a simple maxim: if you have to choose between explanations for something and one of them is conspiracy and the other is error, you should be choosing error every time.”
This is all quite true, however we should always be aware that what constitutes error may be in the eye of the beholder. The action of a common world view on personal perception may give those who do not share that view the appearance of a conspiracy even if no such overt plot exists.

kadaka (KD Knoebel) says:
August 5, 2010 at 3:10 am
Excerpt from: R. Gates on August 4, 2010 at 10:27 pm
I did not make up the GCM’s that forcast the slow decline of Arctic sea ice due to AGW. Far smarter people than me get paid to do that.
Far smarter people than you get paid to make up Global Climate Models that forecast the slow decline of Arctic sea ice due to Anthropogenic Global Warming.
Then subsequently declines in Arctic sea ice get cited as evidence of Anthropogenic Global Warming, since obviously the model was correct as declines were noted.
Meanwhile evidence that runs contrary to the models…
_______________
Your point is made…but let’s stop right there for a moment. Show me the evidence that runs contrary to the GCM’s specifically about the slow decline in Arctic summer sea ice, leading to an ice free Arctic sometime this century. The Arctic sea ice has been showing a long term decline and permafrost is warming and melting in the arctic regions. The biggest deficit of the GCM’s is that they didn’t predict the acceleration in the melt that began a few years back, having obviously not accounted for some positive feedback. Some of this could be related to polar amplfiication effects, such as the increased frequency of the Arctic Dipole Anomaly.
So in general, the GCM’s have pretty much got it right, and the science get’s better and more robust ocean-atmosphere linkages can be added to the models.
But regardless of some posters doubts about it, I am a partial skeptic (when it comes to AGW). There certainly could be some other longer term natural cycle that “just so happens” to be coinciding with the general predicted effects of AGW in the Arctic. I very much welcome some scientific insight into what this other long-term cycle might be…currently, the 40% increase in CO2, to levels not seen in 400,000 years, seems to be the most simple and obvious explanation.

Steven
could you remind us your prediction for the year minimum? Didn’t you state it would fall close to 2006 and be higher than the 3 previous years?

from NSIDC ~ 75 percent down the Page, is OPEN about the Differences:
[My] “Exec Summary”: AMSR-E / JAXA updated their algorithm so it is More accurate — but — AMSR-E comparisons with previous years are INVALID now ! Other than that, every method is just different –except in that ALL show a downward trend.
— Note: I would caveat that HALF the “trend” is 2007. … MOST of their “trend” is a few UNUSUAL events.
— (NSIDC = uses Passive MW with NASA mark I Algorithm)
Quotes: … “Gloerson and Campbell (1991) estimate that ice concentration retrievals are accurate to within five to nine percent ” … ” Based on comparisons with analyses of synthetic aperture radar data, passive microwave overestimates open water by three to five times in winter (Kwok 2002). The winter coverage of open water is only about 0.3 percent.” [ie x5 reduces Ice area 1.2 percent = no big deal: real meat follows:]
“A study based on digital versions of the U.S. National Ice Center’s (NIC) charts covering the Arctic every week from 1972-1994 (Partington et al. 2003), shows that NIC charts consistently report about four percent more ice per unit area than passive microwave retrievals from the NASA Team algorithm. This holds for November through May. Beginning in June, the difference rises to about 23 percent, and falls off gradually over the summer and into fall freeze-up. The difference after freeze-up, which begins in September over most of the Arctic, is probably due to the insensitivity of the passive microwave algorithm to thin ice. Both chart data and passive microwave data show a negative trend in integrated arctic-wide concentration over the period 1979-1994. The difference between the passive microwave and chart trends is statistically significant only in the summer, where it is about two percent per decade steeper in passive microwave data.
A comparison of ice-covered area from the NASA Team algorithm with 18 years of Canadian Ice Service charts showed that passive microwave data markedly underestimate ice area by 30 to 40 percent during spring melt and fall freeze-up, for the Hudson Bay and East Coast regions. There is considerable scatter in the differences rather than a consistent pattern (Agnew and Howell 2002a) and (Agnew and Howell 2002b). The difference between chart and passive microwave-derived ice areas is greater for the Canadian charts than the U.S. charts. This is likely a reflection of the fact that the U.S. National Ice Center uses passive microwave when other data are not available, which is often the case for the central Arctic and other remote areas, while the Canadian Ice Service only rarely uses passive microwave data, relying instead on airborne and satellite radar, satellite optical, and visual observations for charts of the Canadian Arctic. These methods detect thin ice, lower concentrations of ice, and flooded ice much better than passive microwave data allows (personal communication, J. Falkingham, Chief of Operations, Canadian Ice Service, December 2002).
Spot checks of the ice edge position using a 15 percent concentration cutoff against NIC ice charts show that when there is a broad, diffuse ice edge, the NRTSI and Standard Team products sometimes do not detect ice where the concentration can be as high as 60 percent. When the ice edge is more compact, the 15 percent concentration cutoff reflects its location fairly well. The large footprint of the 19 GHz channel means that a compact ice edge is smeared out in passive microwave imagery.
A study comparing passive microwave sea ice concentration data with approximately 1 km resolution imagery from the Advanced Very High Resolution Radiometer (Meier 2005) focuses on the ice edge. Four SSM/I algorithms are used. The work illustrates how algorithms often underestimate concentration. The NASA Team underestimates concentration by about 10 percent on average, and by much more in some circumstances.
Newer algorithms were developed that perform better than the NASA Team algorithm. An enhanced version of the NASA Team algorithm, NT2, incorporates the SSM/I 85 GHz channel and applies a forward-radiative transfer model to correct for weather effects that are exacerbated by use of the 85 GHz channel. This algorithm is the standard algorithm for arctic sea ice concentration retrievals with the AMSR-E instrument (Markus and Dokken 2002).
We have considered using one of the newer algorithms for the Sea Ice Index, but this would require research and reprocessing in order to ensure that the record is consistent over the entire time series. The SMMR instrument did not include a high frequency channel like that used in newer SSM/I and AMSR-E sea ice algorithms.”
PS: The Canadian sounds best – because, like PIOMAS, they add Every Ship & plane’s reports & pics. This produces long waits for updates.
Can anyone find a Canadian data site ? I ran into their service’s site once, only got a weekly map — I’ll try to re-find it.
PSS: THE best map for us is the ICE-AGE map http://nsidc.org/images/arcticseaicenews/20100804_Figure4.png
Maslanik only produces about 1 a month though.
or, again: http://iabp.apl.washington.edu/maps_daily_nsidcice.html
…. note how the second, Bouy Map background shows a big area off Alaska of mixed Ice & water where there is a GAP in the Ice opposite Alaska in the first map. Also the Buoy map clearly shows the “bar” of thick ice crossing the Arctic Canada-to-Russia well “west” of the Pole — such as I talked about in the censored part of my July Sea Ice Outlook. Also seeable in TOPAZ http://topaz.nersc.no/topazVisual/matlab_static_image.php?action=NA_ARC_NWA_Function&file_prefix=ARC&match_date=20100803&depth=0005&variable_name=hice … wish I knew what “hice” was … try substituting 2009 : WOW — so different !! more ice by Volume is in that hugely thick area up against Canada & Greenland than in the whole 2010 map ! BUT the half of the Arctic (Russian side) where 2007,8, & 2009 lost most of their area – – it was like thin LACE then & is MUCH thicker this year.

I wish I knew a way to make these a side by side comparison but I played on the JAXA site to get these images. The first one is from 8/4/2007:
http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e
And this one is from 8/4/2010:
http://www.ijis.iarc.uaf.edu/cgi-bin/seaice-monitor.cgi?lang=e
And from what I can tell is that there is a lot more ice still in 2010 then there was in 2007. So I’m not sure how NSIDC is getting their graph which makes it look like the amount of ice is similiar to what it was in 2007.

R. Gates: August 5, 2010 at 7:12 am
Show me the evidence that runs contrary to the GCM’s specifically about the slow decline in Arctic summer sea ice, leading to an ice free Arctic sometime this century.
Show me the evidence that the Arctic is doing anything except what the Arctic has been doing for the past few million years — cooling, then warming, then cooling, then warming — and it was much warmer only tens of thousands of years ago.
The Arctic sea ice has been showing a long term decline and permafrost is warming and melting in the arctic regions.
Long-term? You mean since 1979? And permafrost thaws in the summer — that’s the reason the people up there can find mammoths that were frozen into it 45,000 years years ago (when it was warm enough for mammoths to survive through the winter, btw, because they *couldn’t survive there today).
The biggest deficit of the GCM’s is that they didn’t predict the acceleration in the melt that began a few years back, having obviously not accounted for some positive feedback.
It wasn’t a melt, and it wasn’t some imaginary feedback — it was a wind event which increased compaction coupled with the collapse of an ice bridge in the Framm which allowed more sea ice through the strait and into the Atlantic.
So in general, the GCM’s have pretty much got it right, and the science get’s better and more robust ocean-atmosphere linkages can be added to the models.
In general, the GCMs are models and it appears they’ve gotten it wrong, because they can’t replicate the observations.

R. Gates
And you also thought that the ice was tanking in June, based on the same methodology of extrapolating the graphs. My analysis considers a lot more variables, which is why I have been able to provide very precise predictions about trends and dates.

Anyone know if there are MODIS image archives, to compare images for the last few years?
BTW, can see the ice east of Barrow well today: http://ice-map.appspot.com/

Sorry, more accurate to say my guess will have been high, not that it will “miss low”. I was being me-centric there and thinking of the extent missing my guess, instead of the other way around.

R Gates,
Look for a significant increase in MYI in 2011.

R. Gates–
Look at JAXA for Aug 5th-Sep 10 for 2008 vs 2009. What was the mechanism for the difference in results there when at the starting point (Aug 5th) there were practically identical?
Same mechanism as will happen this year –increase in multi-year ice.

stevengoddard says:
August 5, 2010 at 10:26 am
R Gates,
Look for a significant increase in MYI in 2011.
———
Steve,
Why wait?
How about a prediction of Arctic sea ice minimum for 2011 from you today.
Since you assert that sea ice is recovering perhaps you’d like to put a marker at 6 million K^2. Or maybe 6.5?
Surely if sea ice is recovering your prediction for next year should be higher than the 5.5 you predicted for this year.

R Gates,
How could I forecast summer 2011, before seeing what happens in winter 2010-11?

RE: Jimbo says: (August 4, 2010 at 4:20 pm) “Joe Bastardi said around mid July 2010: ‘… The recovery of the northern ice caps will become more obvious in a two-steps-up, one-step-back fashion, but the Southern Hemisphere ice will retreat back to near normal. Overall global ice is right on top of normal and has had no change in the past 30 years. ‘”
This sounds very much like we are only seeing the result of an annual competition between the Arctic and the Antarctic regions for a relatively fixed allotment of total global sea ice extent.

Steve,
Excellent article! I also see that the AMSR-E Sea Ice Area shows little to no melt in the past week. It’s all due to the wind.

Snowlover,
NSIDC apparently decided that their broken Arctic graph was more important than their record Antarctic graph for the August newsletter

stevengoddard says:
August 5, 2010 at 11:17 am
How could I forecast summer 2011, before seeing what happens in winter 2010-11?
————
You already have with statements like ” Arctic sea ice is in recovery.” And there’s all the work you’ve done with PIPS models and data analysis to show that ice is in recovery.
So I’d love to see you put some numbers on the table. Why stop with 2011?
What do you see as minimum ice extents for 2011, 20012 and the infamous 2013.
Some have said that the Arctic will be ice free in 2013, obviously they are idiots, but what do you predict for 2013?
If you can’t do more than 6 months in advance you’re just doing weather, not climate.

Jeff P
Modelers consider climate forecasting to be in the range of “months to seasons.”
No one can accurately forecast what ice conditions will be like in the spring, because it depends on the weather between now and then.

Amino Acids in Meteorites,
The two measure differing concentrations of arctic ice, so they are almost bound to show different results.

timheyes says:
August 5, 2010 at 11:13 am
“Give us some numbers from the “theory”, for a reasonable period in the future, with error bars, then we will pay attention to GCMs. Until then, argue your case with science please not this post-modern/post-normal quackery which is doing untold damage to the climatological scientific reputation.”
________
This is the difference between what Steve does and what climate science is all about…which is essentially the weather vs climate issue. GCM’s are NOT MEANT to predict exact numbers because climate is about the longer term TRENDS, not how hot or cold it is right now or what the date in 2010 is that the shore fast sea ice broke away from Pt. Barrow.
Here’s the point: GCM’s are about trends because climate is about trends.
In this sense, climate is easier to predict than weather, because all it has to get right to be right is the trend, not the specifics, so long as it has the physical basis for forecasting those trends, which is of course the additional 40% CO2 that has been added to Earth’s atmosphere in the past few hundred years. Additionally, we’ve got consistent climate records going back hundreds of thousands of years, but of course no consistent weather data exists beyond a century or or two.
The most recent and dramatic failure of GCM’s is not that they missed the general downward trend of Arctic Sea ice over the past many decades, which they got right, but that they failed to get the severity of the slope correct. So it was not one of direction but of degree. Certainly unaccounted for feedback issues are the reason, as will exist with a system existing on the edge of chaos.
If somehow the Arctic sea ice reverses the downward trend over the next few years in some meaningful way (meaning heading back toward the 8 million sq. km. minimum), then I’ll reconsider my belief that the GCM’s are generally correct because a trend they have predicted (based on CO2 forcing) will not be happening.

Julienne Stroeve says:
August 5, 2010 at 3:05 pm
……
Nothing has changed in the NSIDC data processing stream. Differences in ice extent between institutions has to do with differences in data sources (AMSR-E vs SSM/I), different algorithms (NASA team, Bootstrap, Bristol, AES-York, Bremen, etc.) and differences in threholds used for defining the ice edge). All algorithms that use passive microwave brightness temperatures for sea ice concentration retrieval will have problems once melt water is on the surface of the ice (the main reason to use extent rather than ice area). The important thing is to be consistent with the processing method and satellite instrument when doing time-series analysis.”
I beg to differ Julienne. If the difference is in the incorrect measurement of melt water ponds on the surface as decreased ice and one model picks this up and records this as an anomaly and another model does not, then consistency in processing the data for a time series will not help.
What NDISC is potentially showing is an increase in melt ponds at this time of year. I agree this is not necessarily a good sign but its not the same as saying ice has been lost altogether in an area compared to previous years which is the impression their chart provides.
Incidentally, the JAXA number for 4/8 has been adjusted down by about 20,000 sq km making the second day in a row of downward adjustments. Given the averaging method they use this hints a slowdown in the melt. although I would prefer to see a few more days before drawing a conclusion.
I’m still with Steven on the minimum being in the 5.5 million sq km range. Although, we would need to match the 2006 ice loss for the remainder of the season though to acheive this. Looking at the ice loss on an area by area basis and then factoring in drift from the buoy measurements and DMI temps, I do think this is a possibility.
We need to watch the DMI temps very closely in the coming weeks. In 2006, the temps (north of 80N) dropped below zero quite early and you cant help but conclude this contributed to the slow late season melt in that year.
If we see the temps drop below zero in the coming week on the DMI chart then perhaps we’ll see a JAXA minimum over 5.5 million sq km. Given the 5.25 million sq km result in 2009 I would have to say this would support a recovering ice pack.

David W. says:
“If we see the temps drop below zero in the coming week on the DMI chart then perhaps we’ll see a JAXA minimum over 5.5 million sq km. Given the 5.25 million sq km result in 2009 I would have to say this would support a recovering ice pack.”
____
Really? Is that your definition of a recovering ice pack? It seems the bar has been set quite low for some reason. So anything less than 5.25 million sq. km. you would say shows no recovery, right?
And BTW, the primary cause of melt right now is not air temps, but water temps, and they continue to run higher than normal throughout the Arctic from Greenland and the Barents Sea over to the Bering Sea, as they have for quite some time.
______
Steve Goddard said:
R. Gates,
GCMs can’t model wind effectively – so there is no way that could have forecast the wind compaction which occurred in 2007.
_____
I agree with that to some extent, but I don’t agree with your underlying assumption that changes in wind patterns might not be related changes in other atmospheric and ocean circulation patterns that could have as their root cause AGW. I must go back here to our discussion of the Arctic Dipole Anomaly and the TREND of increasing frequency of the what might soon be called a “former” anomaly. You certainly are aware of research being done to link the frequency of DA to atmospheric pressure changes that could be the resulting of global warming? I believe even Julienne, who is far more versed in this sort of thing has discussed that here.

And really, just one look at this graph:
http://nsidc.org/data/seaice_index/images/daily_images/N_stddev_timeseries.png
And this graph:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/sea.ice.anomaly.timeseries.jpg
And this graph:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???

David Gould
BTW – If we did correct for pixel aspect ratios – the discrepancy would become greater, not less.

stevengoddard,
If the sea ice map and the sea ice graph are generated from the same data, how can supposed discrepancies be real? Or are you saying that the two are created independently from separate data sets?

Walt Meier says:
August 4, 2010 at 8:31 pm
To begin, a thank you for monitoring and addressing the earlier posts up to 8/4. Alot of information designed to accurately identify what is actually occurring with arctic ice has come out. Would you care to update your assessment?

R. Gates says:
August 5, 2010 at 4:38 pm
“…Here’s the point: GCM’s are about trends because climate is about trends….”
Reply: First off, I must applaud your tenacity. Given your statement above, would you say that the GCM’s are linearly trending or are they cyclically trending? A simple question, is it not? Because historical climate has been cyclical. Is it your belief that anthropogenic CO2 forcing is sufficent to disrupt the cyclical nature of climate? I await your well-reasoned response.
Thank you,
Ralph Dwyer

R. Gates: August 5, 2010 at 5:43 pm
And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???
Well, let’s look at a *longer* term average.
The Northwest Passage (NWP) has been icebound during the “modern instrumental period” and ships haven’t been able to transit without the aid of icebreakers, correct? If ships *could* transit the NWP without the aid of icebreakers, that would mean that the ice extent was well below average, correct? The historical record shows that ships transited the NWP without the aid of icebreakers at least twice in the mid-19th Century, and at least four times in the 20th Century, therefore, the ice extent was well below average during those periods, correct? Since ships have *not* been able to do that in recent years, then the ice extent must now be *above* the longer term average, correct?
If you look at the “longer term average,” you’ll see that the ice extent is *never* average — it’s either above or below, and since we’ve only been getting pictures of the extent for thirty years, we can’t honestly claim we even know what the “longer term average” happens to be.

Bill Tuttle says:
August 6, 2010 at 3:12 am
R. Gates: August 5, 2010 at 5:43 pm
And then to suggest in any way, that anything that we could get out of this single season would indicate that any type of “recovery” is indicated seems to me to be the epitome of reaching for a conclusion that simply isn’t indicated by the data. We haven’t had a positive Arctic Sea ice anomaly since 2004! How can a recovery be underway if the ice extent remains well below the longer term average???
Well, let’s look at a *longer* term average.
The Northwest Passage (NWP) has been icebound during the “modern instrumental period” and ships haven’t been able to transit without the aid of icebreakers, correct? If ships *could* transit the NWP without the aid of icebreakers, that would mean that the ice extent was well below average, correct? The historical record shows that ships transited the NWP without the aid of icebreakers at least twice in the mid-19th Century, and at least four times in the 20th Century, therefore, the ice extent was well below average during those periods, correct? Since ships have *not* been able to do that in recent years, then the ice extent must now be *above* the longer term average, correct?
If you look at the “longer term average,” you’ll see that the ice extent is *never* average — it’s either above or below, and since we’ve only been getting pictures of the extent for thirty years, we can’t honestly claim we even know what the “longer term average” happens to be.
_______________
We only have the data we have. Even a transit of the NWP does not tell us about the overall extent of Arctic sea ice, but only of the NWP. We know that the Arctic Sea ice has not had a positive anomaly since 2004 based on the 30+ year average of solid reliable data. Anything else beyond this is somewhat speculation, though sediments and other data can give us some idea of the longer term sea ice extent in specific areas.
I favor the satellite data over any for a reliable record of sea ice. Next, I favor ice core samples over any other data for a reliable record of CO2.

(Mods: we’ve gone somewhat OT, but I think the discussion is valuable.)
R. Gates says:
August 6, 2010 at 7:45 am
Reply: Thanks for your response. A few more questions if you don’t mind? Given Bill Tuttle’s timely link above (thanks Bill), and that humans were probably of little consequence, if any, for the first 155,000 years covered by the graph (Fig. 1),
1) what do you think causes the past CO2 increases as stated in your comment?
2) From the same graph it appears to me that an approx. 100ppm rise in CO2 (+/- 180ppm to =/- 280ppm) accompanies an approx. rise of 6 to 8 deg. C (twice in the graph) could we not anticipate a further 6 to 8 deg. C?
And,
3) given the graph in Fig. 2 which depicts the current rise in CO2, which is approaching a 100ppm increase (with the human contribution somewhat miniscule), what do you propose we do about it?
I think we’d better adapt and learn to enjoy the benefits of increased CO2. How about you?

Speaking of discrepancies, doesn’t anyone try to reconcile the various extent and area calculations, or are they all done by separate parties, each paying little attention to the others?
Note: My assumptions are that 30% extent is calculated by adding up the total number of 25 km2 squares containing at least 30% ice cover, and similarly for 15% extent, and that area is a calculation adding up the figures for the actual ice cover in all squares containing at least 15% ice cover. If my assumptions are wrong, stop reading here, as the rest is probably nonsense.
Anyway, here’s what I mean: Take the AMSR-E 15% extent figure at the maximum of 2010, which was approx 14.4 mil km2 at the end of March. Now compare that to two other figures (taken from the graphs on the Sea Ice page and approximated): The Danish (DMI) 30% extent at the maximum in March/April appears to be approx 11.7 mil km2, and the total sea ice area appears to be approx 13.7 mil km2 from the NORSEX graph.
Do these make sense taken together? Let’s assume for the sake of argument that ALL of the 30% graph is actually 100%, so that would add its entire value of 11.7 mil km2 to the area calculation. (Obviously this is high, but assume it anyway) Now, the difference between the 30% graph and the 15% graph is 2.7 mil km2 (14.4-11.7). Assume that all of that difference is 29.999% concentration. (Again, obviously too high, but assume it anyway) If that 2.7 mil km2 is 30% (29.999%) concentrated, it would contribute just 800 mil km2 to area. Thus, adding the absolute maximum contribution from the 30% graph and the 15-to-30% portion of the 15% graph, we get a total sea area (maximum possible if the graphs are correct) of 11.7 + 0.8 = 12.5 mil km2.
Yet, the sea area graph shows 13.7 mil km2, a figure 1.2 million higher than the maximum possible derived from using the two extent graphs.
To make the numbers work, either the 15% extent would have to be raised by over 4 mil km2 (to add the missing 1.2 mil km2 to area), or the 30% extent would have to be raised by 1.7 mil km2 (to again add the missing 1.2, bearing in mind that the portion coming from the 15% extent would be reduced by 0.5). Alternatively, the sea area calculation could be lowered by the 1.2 mil km2 discrepancy, a discrepancy that is obviously larger than that, due to the assumptions made here. (Again these are all April 1, 2010 approximated numbers, not present day)
Most likely it’s some combination of the three adjustments, but something doesn’t appear to add up and the adjustments required to bring things into balance seem quite large. Did I go wrong somewhere; if so, where?