For the past five years, I have been listening to alarmist trolls blabber mindlessly about pixel counting and comments Walt Meier made to The Register. The five year anniversary seems like a good time to set the record straight humiliate these morons.
Steve Goddard 8/22/08 to walt
Dear Walt,
The attached image shows UIUC and NSIDC maps on top of each other from August 15, 2007. The interior land edges surrounding the Arctic are all registered, and as you can see, the UIUC ice extent is much smaller on the Canadian side. NSIDC is transparent white, and UIUC is colored.
BTW – when I do pixel counting on the NSIDC maps, I get an exact match vs. your graphs. The technique is excellent for making a decent estimation – if the base maps are correct.
Based on your last two E-mails I was surprised by your comments in The Register, as you had made it clear in your private messages that you understood what the problem was and were searching for the same answer. I absolutely do calculate the pixel area corrections for each date, and they make very little difference. On most days they /increase /the discrepancy by about 3% beyond what I reported. I am not making any attempt to measure ice area, and I am making an apples for apples measurement of extent.
The reason why UIUC maps show 30% increase in extent is because their August, 2007 maps appear to be not plotted accurately – as can be seen in the attached image. Their 2008 maps seem to show much closer agreement with NSIDC maps.
The UIUC maps show a striking increase in ice extent in 2008. Seeing is believing – but unfortunately in this case the images were not accurate.
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– Steven Goddard——————————–
Walt Meier 8/22/08 to me
Yes, if the map is not too distorting, like NSIDC’s maps, pixel counting is a good rough estimate. In fact, we helped developed an educational module where students would estimate the extent from pixel counting. Scientifically, it’s not valid, but using our maps we found it was close enough to get the message across for students. That’s why I wasn’t sure it was the pixel counting that was the problem – it seemed like it shouldn’t have been such a large error. But since I wasn’t familiar with the UIUC images, I couldn’t say exactly what the problem was, but it had to be due to the images in some way.
As for the comments on The Register, I forget exactly what I said, but I think I also tried to address some of the other comments by readers who were misunderstanding things. Sorry if it sounded like I was incorrectly criticizing you.
Thanks again for being willing to work with us to correct the errors.
walt
—————–
The discrepancy was due to two problems with the Cryosphere Today maps. They don’t show ice below 30% concentration, even though their legend makes it appear they do, and their eye altitude was incorrect. Both problems were resolved by Bill Chapman at UIUC.
damn………….
Exactly true. And, other outfits do actually use pixel counting from their images. I’m glad you put that out, Steve.
BTW, I think we hit our minimum 3 days ago. http://suyts.wordpress.com/2013/09/16/did-we-reach-the-arctic-minimum/
I had guessed 5 million….and I’m short now
Still pretty close!
and I don’t even have a grant or super computer….
just common sense!
And Antarctica set a new all-time record sea ice extent.
http://sunshinehours.wordpress.com/2013/09/16/antarctica-sea-ice-extent-all-time-record-maximum-on-sept-14-2013/
Note how he says its scientifically not valid! Anyway for those are IJIS maps, what is the point of pixel counting when they provide the actual numbers.
The “actual numbers?” ROFLMAO
The numbers depend on what concentration ice you use for a threshold. DMI 30% shows a larger percentage gain than I do.
Where do you buffoons come from?
I don’t know if you use your insults as a veil, it seems like that to me. Anyway I will repeat what I said. The same website you use to produce those photoshopped sea ice images, also provides sea ice extent numbers. These numbers come from IJIS. So why would you use a sloppy, and error prone method (incidentally the maps you use, do not use an identical transform to the NSDIC maps, do you know the specification and the accuracy of your method – if you don’t you shouldn’t be doing it, what kind of ‘real science’ doesn’t put an uncertainty on their method) over the sea ice extent figures IJIS produces itself? And to complain about concentration is ironic, since your photoshop method is pretty ambiguous when it comes to concentration anyway – please tell me what concentration cut off you use.
Did you hit your head on the pavement recently?
I take it from your non-response that you have conceded that I am right.
I take it that you don’t understand what extent and concentration mean, and are just wasting my time.
Of course I know what concentration and extent are. Now answer my previous post. Stop insulting me and have the backbone to actually address my posts.
I already did, but you are too dense to understand what I said.
You said some nonsense about hitting my head on the pavement in response. If you are not going to answer, the most reasonable assumption is you don’t have one. All you seem to ever do, is insult people all the time. Actually answer my points for once.
Steven; I know how you make those maps. They are from IJIS (sea ice mointer). And I know you ignore some low concentration ice. When you last did one of these maps in 2009 you ignored a load of low conc ice in the laptev in 2009. Therefore you were not measuring extent evidently, which is why I asked for your cutoff.
The concentration problem is actually yours, not mine. And that is before we even get too the rest of my points in that long post which you have still failed to answer.
To my previous post:
http://3.bp.blogspot.com/-SnlLkkiF5B8/UifHwTyYTFI/AAAAAAAAAF8/5KixuK2HUQc/s320/imagey.png
This is from an overlay of your map with the one IJIS provides. The dark greenish area is where you ignored low concentration ice in 2009 (in a previous post comparing to 2013). If you are ignoring that low concentration ice, then you arn’t measuring extent. Anyway this is a diversion from the point I originally made. Please can you adress it.
DMI 30% graphs show a 70% increase from last year. I’m being conservative.
Maslowski, Gore, Zwally predicted ice-free in 2013 – but you don’t care about that, do you?
The number is not why I am commenting. It is your bad science – notice I never made any claims about it being less than 60% e.c.t.. Now please address my points in that long post or I will assume you can’t.
I have no intention of repeating the same thing over and over again to every troll who comes under the bridge.
I am not trolling. I am simply asking you to address some very reasonable points. You did answer, but with some stuff about hitting my head on a pavement. I have been very reasonable, I have not insulted you or engaged in petty name calling. Or you could just admit, that I am probably right about this and we could move on.
The method is perfectly valid. All engineering has tolerances. In the case of Maslowski, he was off by a factor of infinity.
You still haven’t addressed my point though. Why didn’t you list those tolerances? Most engineers would list their uncertainties, why didn’t you? More to the point why didn’t you use the IJIS extent numbers instead of your own crude pixel counting?
What are tolerances for the 2013 ice-free Arctic?
Steven, please stop changing the subject. I am commenting on your post, this has nothing to do with failed predictions on an ice free arctic. The IJIS have sea ice extent figures, why didn’t you use those? The maps you made were also sourced to IJIS, so this makes absolutely no sense to use a crude pixel counting method when you have the actual figures you wanted to calculate the desired percentage.
I have already explained this to you multiple times. I am using a different concentration threshold of 30%. They use 15% Don’t ask again.
Then why not use CT area? There are many ways to avoid this sloppy pixel counting and still get your 30% concentration cap.
Why doesn’t everyone use CT’s area?
One reason is that CT hasn’t updated their data for almost two weeks.
Face it. I have the prettiest maps.
atow, are you being intentionally dense? Let me ask you this, why do the ice measuring outfits produce maps of our ice extent? They have the numbers, right? Why not just put them out on the front page? You do realize a map representation on your computer is just pixels, right? If it is invalid for Steve to do so, then it is also invalid for the rest of them to do so.
And, as far as “actual numbers”, you should probably review about how they come up with their “actual numbers”. You may be surprised about some of their methodologies.
Personally, I’m a graphs guy, but, the spaghetti graphs can be a bit maddening for others. Your obsession over Steve’s use of other people’s maps seems a bit unwarranted. Many outfits have maps as their products. Are you saying their products are invalid and shouldn’t be used for comparison? If that’s the case then you need to be on some other websites. I’d start with Jaxa, but, they aren’t the only ones.
James:
ATOW is a troll that Steven has already banned several times, coming back with a new identity. Elementary my dear Watson! 😉
Steven. CT Area has updated until September 15th. Hardly several weeks.
I see. So they updated it this morning after I made the comment and that makes you a super smart fellow.
Then use SSMI area! Or idk, just wait until it was updated! I really cannot see any justification for using such bad science. You critisise other people for minuiti like truncating 1 year off a dataset, and then you do something as error prone and scientifically flawed as this. What about dmi, you could have even used that!
3 …. 2 … 1 … spam
And suyts: No that is not what I am saying; please read my posts.
Steven’s “not scientifically valid” pixel counting method led to a correction in a UIUC algorithm.
Why are you so opposed to crosschecks that lead to better science? They were accurate enough to lead to better science.
How about an “Attaboy Steve!”?
Odd that they teach “not scientifically valid” techniques to students.
Morons who hang on the literal words of academics are exactly who created this AGW mess.
The email you provided even said that it was an invalid method. And no, the likes of NSDIC and jaxa take into account the curvature of the earth when doing their calculations. Are you trying to say that I am a moron for wanting to use data that isn’t biased by distortions caused by stereographic projections?! And are you even capable of going a single post without insulting me?
And Walt Meier also said that extent would “definitely be in the bottom five” this year.
I expect readers to actually have a brain.
Yes, and I would like to see a citation for that. But no that isn’t the issue. Steven presents a map which isn’t well sourced (for instance he could specify more clearly where it came from – IJIS conc maps) and decides to use this error prone method when other values are avalible from datasets that take the curvature of the earth into account. By the way, thanks for not calling me a ‘moron’, and kudos for actually responding to me directly. On average it takes around 4 received insults to even get anywhere with Steven.
Can you stop being so insulting all the time Steven. Real scientists don’t behave so immaturely. You constantly complain that no one will debate you, and this is why. You would just insult them all the time. Answer me, why would you use something that you knew to be error prone over a data set which is going to be vastly superior? Also how did you even manage to discard all the <30% pixels? Sea ice mointer doesn't provide a key to do it by colour.
Can you stop being anal? DMI shows a 70% increase. CT shows a 62% increase, I calculate a 67% increase. Counting ice is not an exact science.
Can you just accept the fact that your climate gurus have fallen flat on their faces and screwed the Arctic pooch?
Then why did you even need to make this post, if you could have just used the dmi dataset. Are you always this obnoxious to people that try to correct your bad science? And yes, this is why people don’t take you seriously because instead of having a rational reasoned discussion you just rattle out the same insults all the time.
atower, you are being dense. You’re attacking Steve over something Dr. Meier said. Here’s a newflash, climate alarmists Dr. or no, don’t get to dictate what is and isn’t valid science. The fact is, if they knew anything about math and science this wouldn’t even be a discussion. Witness this coming from supposed scientists … http://www.realclimate.org/index.php?p=15665
It isn’t the pixels which are prone to error. Pixel counting is pretty much spot on. The errors come from the inaccurate representations put out by the lunatics. I blame it on their unfamiliarity with geography, and cartography.
RE: atowermadeofcheese – “Real scientists don’t behave so immaturely”
May I recommend the following for your immediate perusal? You are currently under a misconception.
http://www.amazon.com/Great-Feuds-Science-Liveliest-Disputes/dp/product-description/0471350664
Some scientists/mathematicians have been driven to suicide by the actions of their eminent peers.
“And Walt Meier also said that extent would “definitely be in the bottom five” this year.”
If it comes to that, what did you say about 2012 being definitely not a record!
I would have never believed a bunch of wind driven ice would be so important…..
/snark