The Register, an occasionally accurate online IT newspaper, has been running a series of warming denial pieces, by one Steven Goddard. Goddard has been trying to cast on temperature and ice data. Unfortunately, he does a whole lot of cherry picking. For example:
A second important issue with NASA's presentation is that they use the time period of 1951-1980 as their choice of baseline. This was a well known cold spell, as can be seen in the 1999 version of the NASA US temperature graph below.
Why use a graph of US temperatures instead of world temperatures? The "cold spell" is more pronounced in the US graph. In fact, the average for 1951-1980 is almost the same as for the 20th century so it is misleading to call it a cold spell. Goddard prefers to use satellite data, with a baseline that is significantly warmer than the 20th century average, to try to making warming seem less. He does some more cherry picking when he presents a map of GISS temperatures leaving out the sea data and using 250km smoothing (even though the NASA used 1200km smoothing for the temperature graphs) in order to make it look like there are significant gaps in NASA's coverage. He compounds this by picking a month where this makes it look like there is a warming bias in NASA's temperatures.
But his most recent effort was even worse, claiming that the NSIDC's graph of Arctic sea ice extent was wrong and that there was 30% more sea ice than at the corresponding time last year.
But it was Goddard who was wrong, as NSIDC's Walt Meier explained to the Register:
He appears to derive his estimate by simply counting pixels in an image. He recognizes that this results in an error due to the distortion by the map projection, but does so anyway. Such an approach is simply not valid.
If you correct Goddard's error, you get the same number as the NSIDC. Meier adds:
Besides this significant error, the rest of the article consists almost entirely of misleading, irrelevant, or erroneous information about Arctic sea ice that add nothing to the understanding of the significant long-term decline that is being observed.
Goddard admitted he was wrong but, as noted by Joseph Romm, Kevin Grandia and James Hrynyshyn, the numerous denialists who claimed that Goddard had shown that the ice wasn't melting have mysteriously failed to correct things.
There are too many to list, so I'll just point to the Australian bloggers: Jennifer Marohasy "Arctic Sea Ice Refuses to Melt", Tim Blair "Arctic ice seems to be growing somehow." and Andrew Bolt "Tim Blair rounds up the local anecdotes of coldening.". No corrections from any of them.
Incidently, in the graph above, 2005 was the record melt until 2007. 2008 has already passed 2005 and whether or not it ends up setting a new record, it's clear that the melt in 2008 is similar to 2007 rather than anything ever seen before.
Update: Bolt referred to Goddard more than once:
Steven Goddard checks those predictions that the North Pole could melt clear away this summer, and finds we can (yet again) relax.
More like this
never excuse, never correct, unless forced at gunpoint. so no surprise, that most denialist sources will not change or correct their stories.
remember, their mission is to confuse and to mislead. while spreading the false Goddard claims, they have fulfilled this mission.
and it wont matter how much below the average or 2005 that line might drop.
as long as it doesn t drop below 2007, the denialist blogosphere will howl in triumph.
Correct their mistakes? Bah! Denialists feed on their own errors. Being wrong just makes them stronger.
> Jennifer Marohasy "Arctic Sea Ice Refuses to Melt",
Well, if it's not Jen Miss Socratic Irony! What Miss Irony might have said:
Of course I'm refusing to correct the error merely to observe how angry those darn Alarmists⢠will get over this. My own inaction says more about them than it does about me, goo goo g'joob.
> Tim Blair "Arctic ice seems to be growing somehow."
What Blair might have said:
The totally ineffectual liberal hippie anti-war movement have concocted a gigantic worldwide hoax known as al-Goracular Global Warmism!
> Andrew Bolt "Tim Blair rounds up the local anecdotes of coldening."
What Bolt might have said:
Today in Malaysia, Anwar Ibrahim has been sworn in as Parliament Member for Permatang Pauh.
What an apt metaphor!
Like the Abdullah government, the phantom edifice of Global Warmism is slowly falling like a slowly falling deck of cards! Merdeka!
"... the rest of the article consists almost entirely of misleading, irrelevant, or erroneous information about Arctic sea ice that add nothing to the understanding of the significant long-term decline that is being observed. ..."
Yeah but Al Gore is still fat.
Careful, there. Goddard has retracted his original claim that there was something wrong with the NSIDC numbers, and now acknowledges that those numbers are in fact correct. This is welcome.
But there does seem to be some discrepancy with the images (from UIUC) and it is not just because of the projection. In fact, correcting for the projection actually makes the discrepancy with NSIDC worse. It's likely, I think, that the two images Goddard was comparing were actually using different notions of extent. I'm not sure; but it is definitely NOT just an issue with the projections.
Yes, ther ewas also an issue with comparing different things. Meier wrote:
>The absolute numbers differ between the UI and NSIDC plots because UI is calculating ice area, while NSIDC is calculating ice extent, two different but related indicators of the state of the ice cover. However, both yield a consistent change between Aug. 12, 2007 and Aug. 11, 2008 - about a 10% increase.
It's a shame that The Register has become as reliable on environmental issues as former members of the UK Revolutionary Communist Party.
The Register should just stick to what they know: technical IT stuff.
Thanks for this. I generally enjoy the Register, but they've taken on a ridiculous global warming denialism in recent months.
I have tried a number of times to leave a post on Bolt's blog over the last several days asking when the under-reported truth about his inaccurate piece would be acknowledged, and when a retraction would be duly penned.
I seem to have been lost in moderation...
Hi Tim, #5. The issue of area vs extent is different from the issue with images. UIUC does report ice area; but the pixel counting exercise is still a way of estimating an extent; not an area. Meier has been very helpful indeed in all of this, but his remark about UI plots being area don't make any sense. You get area by weighting each region with its percent ice cover; but the plot has pixels added for a certain extent. There is a 30% difference (or more than 30%, if you take projections into account) between the extent in the two images Goddard was comparing, when the data indicates it should be much less than this. It looks to me a bit like the 2007 image was showing the extent of 50% ice, while the 2008 image was showing the extent of 30% ice.
The comments from William Chapman of UIUC conflict with this; but it still looks wrong to me. The 2007 image at UIDC sure as heck looks a lot like the extent of 50% ice cover. It's strange.
@David, The Register's IT coverage is little more accurate. It's best described as an IT gossip column.
Which is why any analysis ought to be done on the UNDERLYING DATA, not an image generated from it.
Goddard's claim was that the NSIDC graph - generated from DATA - was wrong based on a computer-generated image that among other things had been JPEG'd once.
Idiocy. If Goddard weren't a climate science is a left-wing conspiracy denialist scum, he might've said something like "there's something interesting about the IMAGE".
Regardless, pixel counting the generated image is just wrong. There's a reason for the link that says "download the historic sea ice dataset here".
Hey D.Q. #4, #10
Assuming the UIUC images are a perspective view from above the North Pole I would guess the viewing height to be 1 Earth radius. You can just see the S. end of Japan, which is at 31 N. This height gives a tangent view at 30 N which would seem like a natural choice. Then it should be possible to calculate ice extent from the images by counting pixels and correcting for distance and viewing angle, using the factor
distance^2/cos(surface tilt)
to scale each pixel. I tried this but still cannot get any agreement with the IARC-JAXA figures for ice extent. The calculation overestimates the area, by an increasing amount as the ice extent gets larger. Just as Goddard discovered.
My conjecture is that the projection used in the images does not correspond to a photographic/perspective view, although the way the images are presented against a star background suggests this is the case. Perhaps this is the trap Goddard fell into. (Or perhaps my calculation is wrong).
So now we have dipole making *guesses* as to what the image is, and analyzing based on his *guess*.
Dude: it's a waste of time. The Auditors are always screaming about the need for raw data. In this case, despite it's availability, you guys are tripping on images whose provenance you don't even understand (the folks there have explained the history of the images, you can't even be bothered to learn it rather than *guess*?)
dhog:
So now we have dipole making guesses as to what the image is, and analyzing based on his guess.
This is all they have.
Give dipole a break: if they didn't have this, what would they comment about? Brangelina's twins?
Best,
D
Anyone comparing pixels in a jpeg deserves to be laughed at.
http://en.wikipedia.org/wiki/Compression_artifact
Think of it as the digital equivalent of impressionist art.
meanwhile, back here in reality:
For the first time ever, both the Northwest and the Northeast Passages are free of ice.
http://www.spiegel.de/international/world/0,1518,574815,00.html
and
New satellite measurements show that crucial sea ice in the Arctic Ocean has plummeted to its second lowest level on record.
http://ap.google.com/article/ALeqM5gU8J3xEhFmRPw87tPfwb-oXa5h9gD92QNA480
will jennifer bother with the facts?
or simply ignore them, again?
Dipole, why guess?
You can look this stuff up.
Look on the page next to the maps. See the little rectangle for searching the site?
Know what the map thingumabob is called? It's a "projection" -- so put into the Search box:
map projections and tell it to look it up:
http://nsidc.org/data/atlas/news/new_map_projections.html
Seriously, a few minutes talking with the librarian at the reference desk at your local library could save you a world of trouble, and you'd get far less attention from people in the blogosphere if you got it right the first time.
Oh, wait. Is that what you want?
Arrrgh. I forget this blogging software doesn't take what's pasted into it literally.
You want underscores before and after the word 'map' in that link for it to work properly.
For this blogging software, put a backslash before the underscore to display it literally:
http://nsidc.org/data/atlas/news/new\_map\_projections.html
Actually, the image in question doesn't come from the nsidc site, so it might not be the same projection ...
People; I am not one of the AGW skeptics, and I am not casting any doubt in the reporting of the sea-ice figures. I did put a bit of work into sorting out the subject, in an attempt to deal with Goddard's article; but when Goddard retracted, the urgency went out of it and I moved on to other things.
But in the meantime, when other people bring up the subject and make errors in describing the matter, don't you think it is appropriate to supply a correction? Is it only when denialists make mis-statements that we should speak up?
I don't think so! Furthermore I am confident that Tim won't object at all. He does a great job with this blog; and part of what makes our side stand out is that we tend to be better at dealing with errors, big or small. Usually.
And, by the way, credit to Steve Goddard for acknowledging that he was wrong to think the NSIDC figures were wrong. It was incredible just how quickly his original remarks got picked up and spread around the denialist sites; and how few of the them have acknowledged it was all for nothing. But Steve at least has retracted.
The whole thing was intrinsically implausible from the start. The images are a highly processed diagnostic of the data; without knowing all the processing involved or the dataset used, it was surreal to take pixel counts as trumping actual satellite data. And yet, and yet. There really is a 30% difference in extent between two UIUC images. That this is a lousy basis for disputing NSIDC figures does not actually absolve our side from all scrutiny.
It has been said that the UI calculates area, not extent. This is irrelevant; the image comparison was dealing with extent. It has been said that it is about the projection used. That's flatly false; the projection makes the discrepancy larger; not smaller. Lots of comments refer to the NSIDC images. Pay attention people, it is the UIUC images that have a discrepancy. If you want to ignore the whole thing as trivial, fine! But if you want to comment on the subject and your comments are wrong; you get the same kind of scrutiny that Goddard received and eventually took into account.
By the way, dipole, the UIUC projection seems to be a vertical perspective projection from an altitude substantially more than Earth radius. I get very close with the tangent from the viewpoint touching latitude 27. This is a viewing altitude of about 7700 km. It could also be using an ellipsoid rather than the sphere.
The UIUC images are for 12-Aug-2007 and 11-Aug-2008. There's no link for the second, because the image archive only goes to 2007. But you can "compare" images using this link. I did email William Chapman. I might try to sort it out a bit more one day; but it's not a priority. In the meantime, I'm just noting for those who comment on the matter... there is a bigger difference in extent apparent in the UIUC images between these dates than what you should expect from data, and this is not an artifact of projections.
http://www.google.com/search?hl=en&q=NASA+SMMR+SMMI+%2B%22map+projectio…
That's searching on the words found in the lower right corner of the UIUC sea ice images.
Of the two hits, the first one
http://www.ccpo.odu.edu/SEES/pdf\_files/pi\_i2k\_ex.pdf
seems to me most likely to be a description of how those images are made.
It begins:
Exercise 1--Generating North and South Pole Geographic Reference Maps
- File type and file name description
- Displaying sea ice concentration (SIC) data images
- Adding color to the images
- Understanding display windows and images
- Creating North and South Pole geographic reference maps
- Calibrating pixel values to SIC in percent using NASA Image2000 ...
And its discussion explains:
"The set of exercises that follow were designed to explore characteristics of polar ice processes using satellite data. These exercises introduce students to basic image processing skills for displaying and analyzing images. Each exercise has scientific discussions explaining what the student is observing. Students will use NASA Image2000, a version of NIH Image, to display and analyze the data sets. The exercises are inquiry based and designed for advanced high school or introductory level undergraduate Earth science classes and associated Macintosh computer labs. They were designed to be used in concert with an electronic lecture that contains scientific background information on polar sea ice and its satellite observations ...."
Looks like it explains the process. Whether it's exactly the one used by UIUC, I dunno.
Beyond that, I see Duae has already wisely inquired of Dr. Chapman at the UIUC site.
Good method.
When images don't match the data they're generated from, it is obvious which has a problem. The images aren't generated with the notion that anyone would attempt to do pixel-by-pixel comparisons, who in their right mind would expect that any one would do this? Especially when the raw data's available via a link on the same page?
There are all sorts of possibilities for the discrepancies. Maybe one set was JPEG'd, the other not. Maybe colors were assigned slightly differently, maybe not. Maybe different image generation software was used, maybe not.
But - who cares? Seriously - who cares? Sure, e-mailing Chapman can help solve the mystery, Watts has done so, others, too. But ... if this where anything other than AGW-related, would anyone be bothering the image maker? Wasting their time? Making them spend their time on something that, in any objective sense, is meaningless?
Demanding that he remove a quote of Al Gore from the website, as Watts very publicly did? (sheesh - worse, they obeyed their denialsphere masters).
The raw data is NOT available at the same page. Check and see. The historical data available is actually only monthly, and it is much coarser than the images. The UIUC is not actually very clear about precisely what data source they use for the images being compared here.
If you don't care, dhogaza, that's fine. I agree that actual data (available at NSIDC) is clear on the real changes going on. Feel free to ignore issues with the UIUC images. I also stopped doing anything on them once Goddard retracted his original claims about data.
In the meantime, I'm still going to correct errors of fact being made, thanks all the same. From anyone. I didn't bring the matter up. I'm just correcting some erroneous statements in relation to UIUC images.
#'s 14,15,16,18,22
What's your problem? Everyone, including Goddard, agrees Goddard was wrong. Wm. Chapman from UIUC/Cryosphere Today posted a rather vague rebuttal on Watts' site involving projection error. I asked him there what projection the CT maps used. No reply. Rather than pester him further by email, phone, or flying over to visit him I did a few fun calculations.
DQ #21 did email him, apparently without success.
Walt Meier of NSIDC (quoted above) talks about "error due to the distortion by the map projection".
OK, it's just a mathematical/cartographic question, but my curiosity is aroused. Is curiosity now something to be frowned upon? Just tell me what projection I need to use to reconcile the CT images with the raw data.
On the issue of Ice disappearing faster than denialist credibility, one wonders the ramifications of the rapid collapse of the West Antarctic Ice Sheet (due to collapse of suppportive ice shelves over the next twenty years, max.). One ramification no one wants to touch is rapid Isostatic rebound and the ensuing Super Volcano.(Increased Volcanic activity due to rapid isostatic rebound recently proven, http://environment.newscientist.com/article/dn13583-melting-ice-caps-ma…)
As the WAIS depresses 750000 square kilometers of Plate up to 1 kilometer, resultant Volcanic activity will be catastrophic. A Volcanic winter lasting hundreds of thousands of years, collapse of the EAIS, further sea level rise and vast increase in Isostatic rebound and associated Tectonic activity.
One wonders what the sudden release of Trillions of tonnes of Ice from the axis of rotation of the Planet will do.
Hapgood!
Ha, ha, ha. Go to Marohasy's blog. Right. Now.
http://www.jennifermarohasy.com/blog/archives/003365.html#comments
If you really meant this, you'd just stick to saying ...
Pixel-to-pixel count comparisons of various images of unknown provenance which, in at least, one case has been JPEG'd is ...
1. fucking stupid
2. fucking meaningless
There's really nothing else to say, no matter which side of the supposed AGW debate you're on.
WHO GIVES A FUCK IF IMAGES PUT UP FOR YOUR VIEWING PLEASURE AREN'T RELIABLE DATA FOR ANALYSIS?
The people who put them up never made that claim for them.
It's just butt-fucking stupid.
No one who gives a shit about science, the data, the real world, gives a rusty fuck about the images.
Why? Honest question. Why? Whatever the result of your query will not mask the fact that ice extent in 2008 is already the second worst on record and is likely to soon become the worst, by NSIDC data. UICT may hold it as the second.
Neither of these statements will be based on the images.
Bottom line here: UIUC was stupid to put images that approximate the data up on their site. It should be limited to a link to a dump of the raw data, no commentary, nothing.
Because gosh, if they once JPEG an image ... holy fucking shit! All of climate science is proven false!
That's the denialist meme, and those of you who claim to be "on the right side" are just playing into their game.
dhogaza says:
"Why? Honest question. Why?"
Because I'm interested in map projections. Here's a nice book for you.
Looking again at the thread intro I see Tim notes that:
If you correct Goddard's error [due to projection distortion], you get the same number as the NSIDC.
So tell us the details Tim! What projection did you use?
Craig @ 11 - Jesus! They've even lost that! It's been a while since I've looked at it, but some of their hardware articles were OK back in the day.
> Because gosh, if they once JPEG an image ... holy fucking shit! All of climate science is proven false!
Moral: Use PNG. :-B
> What projection did you use?
Wrong question.
The real question is: Why is dipole so obsessed with Al Gore using projections?
dipole, Goddard's error was counting pixels to get an estimate of the change in sea ice.
@ #27...'Hapy' may have the last laugh yet...anybody know a good medium?
Re: Tim Lambert #36
Sorry, but your mention of "Goddard's error" in the intro appears to refer the immediately preceding paragraph, where Meier attributes the error to mapping distortion. You also imply there that this error can be corrected, which I took to mean that the CT images have indeed been reconciled with the NSICD data.
I take it from your reply that you now agree that this is not the case.
dipole:
I'm in the process of writing up a story on the Real Reason™ that Steven Goddard issued his retraction. Other Deltoid readers probably have quite a good idea of what it is. Stay tuned.
At #39 bi -- IJI says:
the Real Reason⢠that Steven Goddard issued his retraction.
You mean it wasn't just because he was wrong? Was he waylaid by a polar bear on his way home from work?
the discussion about the 2real reason for the error", is just another demonstration of the denialist smear machine in action.
reread my comment #1 above:
never excuse, never correct, never admit that you were wrong. as long as they can keep doubt about the reason for the error floating, they are fulfilling their mission.
sod:
I was talking about the Real Reason™ for the retraction.
Now that's something which the inactivists won't want to touch with a 10-foot pole. :-B
sorry bi, i was not addressing you.
i am looking forward to yourtake at it :)
Although it's off-topic, CK's link at #28 is curious indeed. Not long ago Marohasy apparated a disclaimer on her blog to the effect that the more bizzare wingnut theories on her blog were inspired by 'Socratic irony'. It now appears that she needs to (wisely) dissociate herself from the more overt fruitloops at P&E by the tried and true corporate strategy of dividing and rebranding her assets.
Anyone remember the APS 'affair', and Christopher Walter's outrage at being disclaimered?
I doubt that there will be any apology for the wrong-headed post she made on Arctic sea-ice either (Socratic irony aside), but the memory of the intertubes is a wonderful thing...
Sorry Bernard, OT again, but that joint really is a circus tent. But all the same it's a great loss to irritainment.
She had no choice, really. Especially after her posts over the past week or so. Newtonian physics anyone?
Sounds like her overlords at IPA delivered some sound career advice.
The Real Reason™ for Goddard's retraction, as discovered by yours truly. But you probably already know it, right? :)
Well done!
Looking at the UIUC images, it led to that SEES pdf file I linked above.
The SEES site link has changed since that PDF was written.
The link redirects now to: http://www.ccpo.odu.edu/SEES/polar/pi_data.htm
That says how to go about aquiring the data used in the SEES image files:
"The National Snow and Ice Data Center in Boulder, CO, is the source for information and data about high latitude Earth science, including sea ice. The Web site is http://www.nsidc.noaa.gov"
Lose the trailing quote on that last link, to get the data files -- but you knew that.
Here's the SEES image software page for Mac and Windows.
Reminder, I know nothing, I'm just backtracking from the attribution text in the lower right corner of the UIUC site's images, and guessing this software and the data files described may well be what they're using:
http://www.ccpo.odu.edu/SEES/polar/pi_comp.htm
If so, the confusion is from having two different imaging programs used for the same data set.
Time and the UIUC response will tell if I've guessed right.
Here's an alternative:
Sea ice map calculated from AMSR-E data using the ARTIST sea ice algorithem (ASI 5).
http://iup.physik.uni-bremen.de:8084/amsr/amsre.html
SSM/I and AMSR-E L1B from inside IUP :
http://diana.iup.uni-bremen.de:8084/cgi-bin/index\_ssmi\_inside.html
All level 1A data are received from the National Space Development Agency of Japan.
Distributed by: Boulder, CO, USA: National Snow and Ice Data Center.
The ASI sea ice concentration algorithm used here has been validated in several studies
(Spreen et al. 2005, Spreen et al., 2008). [links provided on original page, see above]
However, no warranty is given for the data presented on these pages.
dhogaza: ⺠⺠âº
That graph is looking a bit old and we are getting onto exciting times. Will it or wont it cross 2007. How about an active link which updates each day.
Here's the daily graph from the NSIDC
The big question is: will the rate of extent shrinkage flatten out before or after it crosses 2007. If before, the 2007 record is probably safe. If after ... this is about when things really started to flatten out in 2007, so a big change of pace this year would be needed to keep the minimum extent from crossing last year's record minimum.
It's a bit like watching a horse race ...
Hank Roberts #48,49
Thanks for your efforts but www.ccpo.odu.edu does not resolve to any IP address through my connection.
The Uni Bremen maps are great, and because they put on the lat/long grid lines it is easy to interpret the projection. As a bonus, they are lossless PNG images, so the colours should be undistorted.
Really I was just hoping for a simple answer about the production of the UIUC/CT images. Besides asking William Chapman on Watts' site, I also asked on RealClimate and now here. But it is like swimming through a dense shoal of red herrings.
Of course it is not a big deal, except that the UIUC/CT images are perhaps the most popular and commonly linked form of sea ice data. But the numbers just do not fit. I am sure there is a completely innocent explanation, and I am annoyed with myself that I cannot figure it out.
It is nothing to do with JPEG compression and pixel counting - everyone who has made a serious attempt agrees it is possible to separate out the sea-ice pixels.
I would be pleased if Tim either changed his comment that "If you correct Goddard's error, you get the same number as the NSIDC", or provided some information to back up that claim.
This is indisputable proof that polar ice is melting.
http://www.theonion.com/content/node/56630
Note that this photograph has been peer* reviewed (*a member of the British 'mob'ility) and has been used by the IPCC as 'unequivocal' evidence of AGW.
Trolls, deniers, skeptical-type people who are being paid by big oil may claim that Al Gore was trying 'raise' the earth's temperature in order to boost box office receipts for An Inconvenient Truth.
Personally I think the picture speaks a thousand words!
dipole:
> Thanks for your efforts but www.ccpo.odu.edu does not resolve to any IP address through my connection.
The address works for me. Try again.
You mean like ... different image generation programs might yield results that, while totally sensible and compatible to the human eye, might yield different analytical pixel counting results if you assume the color-weighing for each pixel is the same, year after year?
You're still stuck in the paradigm that the generated image means anything when analyzed this way.
Please remember that human eyes are much more sloppy. Different generation algorithms might yield pixels that appear to differ greatly to a pixel-counting effort while not being significant to the human eye.
Tell that to Watts and others who see JPEG compression artifacts in the images.
It has nothing to do with pixel counting yet everyone agrees they can count pixels by separating out the sea-ice pixels?
That's bullshit at the basic level of self-contradiction.
Of *course* they can separate out the sea-ice pixels as represented in the inaccurate image which is processed from the real data.
All that means is they have an inaccurate count of sea-ice pixels.
These generated images aren't data. Why the HELL would you or anyone else think so?
The raw data is easily available. USE IT.
From bi -- IJI #56:
The address works for me.
% nslookup www.ccpo.odu.edu
;; connection timed out; no servers could be reached
% nslookup www.mit.edu
Server:61.9.195.193
etc...
dhogaza #57:
When you have examined and analysed the image data yourself you can start lecturing me on JPEG compression.
Would you like my source code (uses Python Image Library and Numeric extension)?
Should I post the pixel mask so you can check it against the original image (pbm format, bzipped and uuencoded, 62 lines)?
Otherwise I have no idea what point you are trying to make. If you can't answer my question you are quite free to ignore it.
> % nslookup www.ccpo.odu.edu ;; connection timed out; no servers could be reached
Non-authoritative answer:
Name: www.ccpo.odu.edu
Address: 128.82.119.9
So try surfing to
http://www.ccpo.odu.edu/SEES/polar/pi_data.htm
http://www.ccpo.odu.edu/SEES/polar/pi_comp.htm
> Would you like my source code (uses Python Image Library and Numeric extension)?
Actually I do. Or has the source code been destroyed by the Bavarian Climatati? Veritas vos liberabit...
http://128.82.119.9/SEES/polar/pi_data.htm
http://128.82.119.9/SEES/polar/pi_comp.htm
And while we're at it, I've archived Jen Miss Socratic Irony's landmark posts:
1. the Socratic irony post; and
2. the new blog policy post.
Now, back to the Real Reason™ for Goddard making his retraction.
www.ccpo.odu.edu - Center for Coastal Physical Oceanography, right? Worked first time for me. I got a result with nslookup, too. Maybe dipole's closest copy of DNS is borked.
Hey thanks bi--IJI #60. The IP addresses work. Not sure it helps much. I can't see the connection with the UIUC images. The links describe the NASA2000 data vis. application. According to the user guide it can do a limited number of map projections including polar, which
shows the North or South poles of the Earth as viewed from deep space. The polar regions are often severely distorted by other projections.
and this is clearly not what UIUC use.
Sure you can have my source code. But how to post? Without 'pre' tags it gets mangled. With tags it is truncated, according to preview, although only 36 lines long.
> I can't see the connection with the UIUC images.
And your totally wild guess is connected how?
> But how to post?
Use markdown. Or, heck, take a screenshot of the source code and upload it onto ImageShack or something. Or you can continue with your insinuations.
Why would I want to do something idiotic and stupid like analyze an image meant as an aid to visualization as though it is significant data?
Sorry, you get to live in stupidville by yourself.
> this is clearly not what UIUC use
Look in the lower right hand corner of the UIUC images.
Take what's there, put it into Google.
That's -- until Dr. Chapman replies to Duae and we get word of it --- all the info available.
Dig, if you want more:
http://www.google.com/search?q=what+software+does+UIUC+use+for+polar+im…
http://nsidc.org/data/docs/faqs/ssmi_faq.html
(Remember the search above? UIUC uses SSMI and SEES to make their imagery.
I pointed to the SEES info I could find earlier. This latest link is to the SSMI FAQ at NSIDC.
Both tools seem to draw on raw data files from NSIDC, as I read the docs I've found online.)
Thanks Hank #66
That's -- until Dr. Chapman replies to Duae and we get word of it --- all the info available.
So you agree that Tim's claim:
If you correct Goddard's error, you get the same number as the NSIDC.
is at present unjustified? Will Tim follow Goddard's example and retract his claim? At least until he can provide some evidence to back it up.
Show us your source code, dipole.
Did you actually write the Python source code showing the discrepancy? The source code which you'd been talking up -- source code which you claim to be willing to show?
Did the Bavarian Climatati, or the Great Warmist-Marxist Conspiracy or the Big Bad Wolf, confiscate the source code from you?
I'm sure -- to use your own words -- there's a "completely innocent explanation" of why you're not showing any source code despite all your overtures, no?
Or are you just going to make insinuations -- based merely on the output of your own vapourware?
Show us your source code, dipole.
Let's see if this gets truncated, or if preview if lying.
#!/usr/bin/env python
# Usage ./ice.py 20080811 70 i.e.
# Try threshhold=70 (sum of abs diffs of RGB values)
# http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/ARCHIVE/
import Image, sys
from Numeric import *
date = sys.argv[1] # image source
thresh = int(sys.argv[2]) # threshhold for match
def image2array(imobj):
# transform image into array of (R,G,B) values
h, v = imobj.size
return reshape(fromstring(imobj.tostring(),
typecode='b'),
(h*v, 3))
im = Image.open('Images/' + date + '.jpg')
# scale.ppm is capture of the colour scale rectangle
scale = Image.open('scale.ppm')
# crop scale to 85% ice cover (260 = 0.85*scale length)
# and use 1 pixel wide central vertical strip.
scale = scale.crop((6, 0, 7, 260))
# convert arrays from byte to integer
A = asarray(image2array(scale), 'i')
B = asarray(image2array(im), 'i')
s = ''
for i in range(len(B)):
diffs = sum(abs(A - B[i]), axis=1)
if min(diffs) < thresh:
s += chr(255) # it's ice
else:
s += chr(0) # it's not.
bwimage = Image.fromstring("L", im.size, s)
bitmap = bwimage.convert("1")
bitmap.save('bw%s-%d.pbm' % (date, thresh))
Well preview is lying and it still gets truncated. Here's the rest. Since python is whitespace sensitive it will still need fixing. Colon missing at end of last line on previous code.
s += chr(255) # it's ice
else:
s += chr(0) # it's not.
bwimage = Image.fromstring("L", im.size, s)
bitmap = bwimage.convert("1")
bitmap.save('bw%s-%d.pbm' % (date, thresh))
Sigh. Last line on part 1 should be
if min(diffs) LT thresh:
where LT shoule be the usual less than sign, which screws up between 'pre' tags for some reason.
dipole:
You're merely counting pixels. Where are all the fancy-shmancy corrections for map projection effects you were talking about? You said,
> Assuming the UIUC images are a perspective view from above the North Pole I would guess the viewing height to be 1 Earth radius. You can just see the S. end of Japan, which is at 31 N. This height gives a tangent view at 30 N which would seem like a natural choice. Then it should be possible to calculate ice extent from the images by counting pixels and correcting for distance and viewing angle, using the factor
> distance^2/cos(surface tilt)
> to scale each pixel. I tried this but still cannot get any agreement with the IARC-JAXA figures for ice extent.
Can I lecture you on Jpeg compression? I tried to tell you way back at #16. Maybe you didn't read it. Try reading this: http://www.pough.org/jpegartifact/jpeg.html
I made it pretty quickly, but I'm hoping you finally get what I'm trying to say, which is that counting pixels in Jpeg images is never going to be accurate. It's simply not the right kind of image for that. It's inherently inaccurate. It compresses the image by fudging pixels.
> so you agree ...
Nonsense, and bad rhetoric. Look back at the original thread and you'll see the correction posted at wattsname's site and the reason for it.
I said way back near the beginning that Goddard was being dumb by comparing pictures rather than looking up the actual data.
And it looks to me like all the pictures are being drawn, using different software, from the same published database.
This whole thing has to be hanging on some troll's trophy wall already. Whose?
Who's keeping the pointless misdirection going here?
I'm about to die of laughter ...
'.jpg' ... christ on a crutch.
bi #73: that is high school trigonometry. Since the code produces a mask rather than just a number it is easy to scale the pixels while adding them. I leave it as an elementary exercise for you.
pough #74: yes JPEG compression does fudge pixels. That is why there is a threshhold parameter in the code. The question is whether the fudging overlaps the ice and non-ice pixels enough to invalidate the results. I leave you to investigate the images and come to your own conclusion.
Incidentally I believe I was the first person to criticise Goddard about this, on Watts' site.
But where is Tim, and is he going to correct his story? Did he set off with Lewis Pugh, paddling a kayak to the North pole?
dipole:
> I leave it as an elementary exercise for you.
I call bullcrap. Given that the projection correction was actually a crucial part of your claim, the onus is on you to give us the source code that you used to make the correction.
So where's the code, dipole? Or are your insinuations still based on nothing but vapourware?
dipole,
In order to prove your claim that the image is an accurate representation of the data, you would have to analyze the actual data and and compare it to the result from the image.
Are you up for it?
Data have a habit of not fitting into neatly into the boxes/pixel on an image...
While you Doltoids have been blowing hot air in the wrong direction as usual that Arctic ice has started freezing again.....
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent.png
Tim,
You disemvowelled my rich text.
I'll try again.
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent.png
Very clever!
But that's the link.
spangled drongo, spangled drongo, spangled drongo (and others). How many times must someone be told how to do links?
Take the spaces out of the following text and see what transpires in preview: _ Sea _
I bet it's _Sea_!
P.Lewis,
OK, it had three spaces but try this:
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRESeaIceExtent.png
This is straight off the website.
http://www.ijis.iarc.uaf.edu/seaice/extent/AMSRE_Sea_Ice_Extent.png
Some people just fail the intelligence tests repeatedly. I'm not sure whether this says something about the tests or the people. What do others think?
OK, just to help you out, your link is to this sea-ice extent plot.
I think it's a crappy website messageboard that you can't post simple links to.
Hi Rune #79
Yes, it would be a good idea to regenerate the images from the original data. But again, you would need to know the projection they use. I think Duae Quartunciae tried this (see his posts above). He also posted some information about this on RealClimate:
http://www.realclimate.org/index.php/archives/2008/08/north-pole-notes-…
But he also failed to reconcile the original data with the images. I might give it a go myself sometime, but have one or two other easier things to try first.
And sure, the data gets mangled several times along the way but I am sure the 2007-8 discrepancy is big enough some other factor must be in play.
But as you can see, discussion around here is not very productive.
Easily the best solution would be for the UIUC people to provide the information. Again, as noted above, nothing seems to be available. I was hoping host Tim might have extracted something from them to back up his story.
If you want a URL that has underscores in it to survive being posted on a TypeKey blog:
that hint above the Comments box is a gross understatement of the situation.
It's not that you "may" use ... markdown for style.
It's that you _must_ use markdown's "literal" code for _accuracy_.
I'll type that again: you \_must\_ use markdown's "literal" code for \_accuracy_\.
Get it?
You also _must_ hit Return twice between paragraphs.
_______________
The fact that this thread is still going on, along with the RC thread, no doubt along with the wattsname thread, and probably echo threads in other places, certainly illustrates why blogging can't do science.
Sheesh.
dipole, where's your source code for your projection correction? I'm still waiting.
Go away bi.
Goddard has another piece up.
http://wattsupwiththat.wordpress.com/2008/08/31/arctic-ice-growth-2008-…
Some questions answered.
"the UIUC people" is one guy and he's very busy; take a ticket and get in line, I'm ahead of you -- (grin) I'm still patiently awaiting the update of the seasonal average chart for the full year 2007 and addition of the marks for 2008. Patiently, I say -- recall they had a server meltdown or something, the imagery producing software was giving wrong answers for quite a while and they flagged that on the site. I gather they had to regenerate an awful lot of imagery not long ago.
The Web gives access to what people offer; that doesn't mean you get to bang on the counter and demand faster and more specific service from people who are offering what they have freely, eh?
It's also the beginning of the academic semester and the Labor Day holiday weekend in the US.
Go have a picnic or something and let the people there respond as and when they have time to focus on this stuff. Sheesh.
Goddard's not even honest:
He fails to point out that Meier says they use pixel counting on raw image data, not on processed, projected, jpeg'd images posted on the web. The latter he states is "ill-advised".
In his own words:
Goddard's being a bit dishonest ...
Oh, and if you have any notion that Goddard might be an objective commenter:
There was, of course, no "1970s ice age panic". He's not stupid, so my money is riding on dishonest rather than ignorant.
And of course he's taking great comfort in the fact that the ice extent is fully 70% of normal. Why this is comforting is beyond me.
Remember -- it's an election year in the USA.
The Republican convention starts tomorrow, unless delayed to reduce the level of embarassment if another hurricane is flooding New Orleans again.
The level of chaff, decoys, denial, distortion, editing, smoke, mirrors, and flying clouds of bullshit will be increasing at least until the election.*
Our apologies to the rest of the world for what's in the pipes.
_________
".. On August 28, Palin's entry was updated at least 68 times, with at least an additional 54 changes made to her entry over the preceding five days...."
http://www.washingtonpost.com/wp-dyn/content/article/2008/08/29/AR20080…
Well, Spangled Drongo, a few days ago people were pointing to this graph as evidence that refreezing had started.
But after a brief leveling off area has started plunging again, almost down to the 2007 level.
Goddard's probably going to claim that now that he agrees that the NSIDC graph is right, that the graphs generated by UIUC are wrong and that the flattened curve in the extent graph proves that refreezing's started and the ice area stuff's all ... stuff! Though last week it was the other way 'round!
Now, since the ice area figure has dropped to almost 2007 levels, what does this mean about the total melt thus far in 2008?
More ice has melted in 2008 than in 2007.
And if you look at last year's melt pattern, and imagine that this year we might see yet more melt .. draw your own conclusions, Drongoid.
Goddard has another piece up.
http://wattsupwiththat.wordpress.com/2008/08/31/arctic-ice-growth-2008-…
ouch. instead of excusing himself for the lies he spread on the web, he is back with another idiotic claim.
he is speaking of an INCREASE in sea ice.
dipole, why don t you simply tell us, what you think about so much dishonesty?
or are you still busy counting pixls?
Goddard arguing against the claim that circumnavigation of the pole would be a unique event:
Those who would like numbers to play with can take a look at ftp://polar.ncep.noaa.gov/pub/cdas/ for global fields daily back to 1979. Grid orientation and resolution change through time, as does the land mask, and both differ from the NSIDC polar stereographic grids (the NCEP grids there are lat-long). To read grib files, go to pub/wgrib on the same site and build the grib reader.
There are more ice data sets there. pub/history/ice/
For just looking at pictures, see http://polar.ncep.noaa.gov/seaice/nh.html for a view of today's ice and either same day last year or an animation of the last 30 days. There are artefacts in those fields due to missing data and storms that act like sea ice in the eye of the sensor (both are taken care of in making the global grids).
Graphics there (.gif, maybe now .png) are also available at the ftp address, but it's still mind-boggling that someone would dispute a quantitative scientific conclusion based on looking at graphics rather than the data.
So, dipole seems to have been - misrepresenting? - when he said he was doing projection corrections?
Hiding your code, dipole?
Meanwhile, sea ice extent has gone flat - perhaps the slush is spreading out? - while sea ice area is still plunging.
And reading the shite over at Wassup is cringe-inducing. Man...
Lee, It isn't a good idea to get terribly wedded to the areas during the melt season. The passive microwave sensors used by NSIDC/Cryosphere Today/NASA/NCEP/... are biased low in area by melt ponds that form on top of the thicker sea ice. They're all pretty good at doing extent (about equally so -- no surprise, as they're all, ultimately, based on the same algorithm. Differences in details, enough so that you should study them before drawing conclusions, but few enough to show pretty similar answers to an eyeball.)
Hank Roberts #93
let the people there respond as and when they have time to focus on this stuff. Sheesh.
See my post #25. Cryosphere Today is run by just one person in his spare time? I'm in awe.
recall they had a server meltdown or something, the imagery producing software was giving wrong answers for quite a while and they flagged that on the site.
I missed that, but it's an interesting observation in the current context.
Sod #98
dipole, why don t you simply tell us, what you think about so much dishonesty?
I think Goddard originally found a genuine inconsistency in the published information, and jumped to a conclusion which suited his agenda but which turned out to be wrong and for which he apologised. Of course he spins the facts to suit his case. Just like this site never questions the torrent of absurdities about the predicted/actual effects of AGW.
Lee #101
So, dipole seems to have been - misrepresenting? - when he said he was doing projection corrections?
I said I could count pixels (see code above). I said even if I tried projection corrections I couldn't reconcile the data. Why would you want the code for a failed calculation? But Tim says:
If you correct Goddard's error, you get the same number as the NSIDC.
Ask him for his source code. Or try reading the thread before posting.
Repeating myself: dipole, Goddard's error was counting pixels to get an estimate of the change in sea ice.
dipole:
> Go away bi.
HAHAHAHAHAHA!!!!!!
> I said even if I tried projection corrections I couldn't reconcile the data. Why would you want the code for a failed calculation?
So that we can check that it actually failed, and to see what it actually was. Or do you just want us to believe -- on faith -- that it did fail?
So where's your code, dipole? Why are you hiding the code which you were so willing to show just a day ago?
Show us the code.
Show us the code.
Show us the code.
Ah, the troll is trolled, and hooked...not here:
Which was just meant to be a visual aid, not to be treated as FUCKING DATA, you FUCKING FUCKWAD IDIOT.
Is that clear, or do I have to be more direct????
The underlying data is, was, and has been, available. Gee, should tell you something, no?
Not really. He said he was wrong because images have been processed differently, and of course he thinks it's reasonable to use these as data rather than the published data.
That's STUPID.
No, not at all. If you believe this, prove it, with quotes, links, images, etc.
Congrats, though - you've exposed yourself as a denialist, not an objectivist.
P. Lewis #87,
Thanks for that. I gave up and went to bed. Had to work this morning.
Tim Lambert #104 says:
Repeating myself: dipole, Goddard's error was counting pixels to get an estimate of the change in sea ice.
Goddard's video
http://www.youtube.com/watch?v=pgjyNlOGWho
comparing NSIDC and CT extent images on 15 Aug 2007 appears to contradict you, showing serious error in the CT map.
Do you usually allow potty mouths and attack chihuahuas such free rein on your site?
dipole:
Show us the code.
Show us the code.
Show us the code.
Where's the code which you were so willing to show just a day ago? And the code which you're basing all your insinuations on?
> ââ âââ âââââââ âââââ âââââ ââââââ âââ ââââââ ââââââââââ ââââ ââââ ââââ ââ ââââ ââââ?
Quick, please call us fat, so that Lambert can finally ban you.
You're asking to be banned?
As an aside, recommended reading.
Have you ever suspected that just possibly a troll has hooked you and is using you?
This may help:
http://groups.google.ie/group/alt.troll/msg/c962c12ac7395177
A few brief excerpts follow:
____________
"... More stunning than what any troll posts is when a grouper admonishes a fellow grouper. That needs to be the goal."
--------
"... Remember, the goal is not to win an argument. It's to create an unwinnable one [that] runs almost forever."
------
"... you don't win an argument directly by what you post. You win because of what your opponent posts."
Hank Roberts #111....
Sometimes trolls are useful...at least to me and I suspect not the way they intended.
I can fairly quickly spot a troll: snide comments, smug attitude, violation of the law of holes, and (curiously) many times terrible spelling. Links to denial sites are dead giveaways...hoo boy!
They themselves are a drag, but the responses to them usually lead to a wealth of information that I wouldn't have otherwise knew existed. The more they troll...the more I learn and it's not from them.
Google is my Friend.
Hank reoberts #111 says:
possibly a troll has hooked you
Not quite sure who you are referring to here. But on a related discussion on RealClimate my comment
So pixel-counting seems quite valid to me, and appears to demonstrate that older UIUC images are simply not accurate.
was coincidentally the last post before the thread closed.
On the successor thread (assuming that's the same Hank Roberts) you refer to the:
now-discredited pixel-counting method
and are concerned that:
the last few postings in the closed thread leave a quite wrong impression.
Now I point you to visual evidence showing that CT images are indeed missing a lot of ice extent compared to the (presumably accurate) NSIDC images and your response is to characterise me as a troll?
Well, well, well... after dipole goes around yelling
> Go away bi.
and accuses people of being
> potty mouths
and finally sobs
> your response is to characterise me as a troll?
It's the usual technique wherein one sprinkles a few acts of nonsense here and there, and then later tries to look totally reasonable and innocent and persecuted.
Strange, because dipole could've saved all the trouble by showing us his code. Well, I'll just say this again to dipole:
Show us the code.
Show us the code.
Show us the code.
My projection correcting code is now irrelevant bi. I would have to rewrite it anyway since UIUC have confirmed a different viewing distance to the one I initially estimated.
It is superceded by the much clearer evidence of Goddard's animation
http://www.youtube.com/watch?v=pgjyNlOGWho
comparing the CT and NSIDC images directly. But thanks for the opportunity to post the link again.
Oh my God, a visual aid proves a commie conspiracy, even though the underlying data is freely available and proves that the visual aid is ... maybe ... too *nice* ... to denialists.
This nanotube straw you're grasping is ... laughable ...
dipole:
> My projection correcting code is now irrelevant bi. I would have to rewrite it anyway since UIUC have confirmed a different viewing distance to the one I initially estimated.
Hey look, a phantom piece of evidence just got superseded by... another phantom piece of evidence! Does anyone like the look of this already?
And according to dipole, he'll have to "rewrite" the code. I wonder how long that'll take? I'm guessing that it'll take forever to rewrite the code, but dipole will mysteriously find enough time to sling mud and play the persecuted Galileo.
I say this to dipole again:
Show us the code.
Show us the code.
Show us the code.
Troll is a verb.
Don't take it personally, you're not the tasty bait with the hook in it.
The tasty bait is the notion of taking imagery ahd getting into deep arguments about what people think must be behind the image, rather than looking at the actual imagery.
Take an earlier example. Wegman, House Energy hearings, Inhofe.
They got hugely wrought up about a hand-drawn curve on a page meant to indicate graphically what was then understood about temperature change over time. It was a cartoon, in the literal sense of the word.
The critics _digitized_the_image_ and then tried to plot the numbers they derived and do science on it.
That notion captured their attention for literally years. They finally got corrected in the hearings in front of Inhofe's committee when the National Academy folks told them straight out that it was just a hand-drawn line meant to give an idea of approximately what they'd thought, when the first report was written.
Same problem here. Don't get caught up chasing illusions. Don't chase tasty bait.
And don't mistake yourself for the bait or the action of dragging it through the water.
It's not about you.
Learn to ask for the actual data files. Work with those.
Work with them better.
Use data. Draw conclusions.
Getting this backwards is an inordinate waste of time.
On the unabashedly wastefully artsy and rabidly commie-left-wing Australian ABC there are two broadcasts called Soundspace and The Night Air.
I'm not sure on which of these it was, but about a little over a year ago one played a piece which started with a fellow sitting in a room with a recorder. He basically rabbitted on for about a minute saying that every time he rerecorded himself - saying that every time he rerecorded himself... - the quality of the recording diminished and was eventually lost.
The first repetition of this had me shaking my head in disbelief at the time some artists have on their hands, but after channel surfing I went back because there was nothing else on. Curiously, I couldn't pick the difference between any successive recordings, but as the piece continued the distortion was quite amazing. I ended up wishing that I'd listened from start to end.
Same as photocopying a photocopy of a photocopy..., really.
Dipole, can you really not see the problem inherent with this silly image analysis when the real data are sitting under one's nose? If there really had been a need to retrieve the data from an image, it would require rather more sophisticated reconstruction that you seem to be referring to.
If you were able to so quickly write the code the first time round, you should be able to bodge it quickly enough for the minor adjustments that appear to be required now.
Provide the code, and a valid reason why one would bother with it at all, given the existence of the freely available original data, and tell us why your approach is not essentially indistinguishable from the examples above.
Otherwise you will simply have to wear the moniker "troll".
BTW, & OT, that ABC piece ran for about 20 minutes. Does anyone here know what it was called and who the recoder was?
Bernard J.: Is this what you're looking for?
Thanks Frank, you're a scholar and a gentleman.
That's it. Great to be able to have pinned it so easily.
> Thanks Frank, you're a scholar and a gentleman.
That's an overstatement. :) Anyway, I remember hearing a similar work -- probably a different recording in a different room.
Hello Bernard #119:
I can tell you are the music/math sort rather a visual guy, so let's start simple. In fact things got a lot easier in just the last couple of days.
Here's a map of Australia. Actually if you are familiar with the layout you probably don't need to look at all. Don't worry, it's a GIF not a JPEG, so no nasty pixel fudging. Anyway, the big area top right is called 'Queensland'. Speaking informally, we say it's 'part of' or 'inside' Australia. We could use the more technical set-theoretic term 'contained in' but let's keep it simple. This isn't an honours class.
The next concept is trickier. Not only is Queensland 'part of' Australia, but there is 'quite a bit left over'. To make this precise I would need to know the projection in use and possibly introduce the associated Riemannian metric. By counting pixels (yay!) and using the area element associated to the metric I could figure out exactly how much was left over.
But I'm going to skip that. I bet you sometimes let your lecturer get away with a bit of hand-waving (I hope you aren't the nerdy guy in the front row always asking pedantic questions).
But it's not really necessary. If someone shows me a map of Queensland and says "Here's a map of Australia", I can call BS without knowing anything about differential geometry. And I don't even have to count pixels! If that's not clear I suggest you get together with Tim and Hank and dhogaza and bi and think about it a bit. Class collaboration is OK.
Now let's try a slightly more difficult example (courtesy S. Goddard):
http://www.youtube.com/watch?v=pgjyNlOGWho
It starts off showing the CT ice extent (think Queensland!) and ends up showing the NSIDC ice extent (think Australia!) for the same day. As you can see there is 'quite a bit left over'.
OK you will say - that's not even a JPEG, it's a frikkin'...something. But then, we never had to count pixels at all did we? Anyway, Mr Goddard seems to know a lot more about the ice maps than you guys, and I am looking forward to his next article.
Credits: thanks to the guy with the shiny bald head (Dr Albedo?) on the recent 4 Corners doco for the illuminating Arctic/Australia analogy.
dipole:
Which part of the sentence "Show us the code" do you not understand?
I say this again:
Show us the code.
Show us the code.
Show us the code.
Until you show us the code, your insinuations are based on nothing but vapourware.
Entirely missing the point. The data is available. The DATA. We don't NEED the map. I don't CARE about the map. Wanking away at the map is nothing but a DISTRACTION.
Goddard's underlying motivation - he's trying to raise doubts about the data and about the extent and area computations performed on the data, by niggling about with visual aids that, from the point of view of relevance, are meaningless.
Except for the fact that the map images themselves are absolutely meaningless. A lot of people know more about astrology than I do, too, but I know the most important thing: astrology is a stinkin' pile.
When all else has failed, look for a file named "README" -- here's one.
Try really hard to get all the way to the bottom of the little bit I'm going to post here.
http://www.iup.uni-bremen.de:8084/amsredata/asi_daygrid_swath/l1a/n3125…
-------excerpt follows-------
II. Data Set Structure
For every day and hemisphere there exist four files:
1. Sea ice concentrations stored as GEOTIFF file (.tif) in byte format (0 to 255).
The ice concentrations between 0% and 100% are scaled to the values 0 to 200.
So every value of the Geotiff byte data represents a range of 0.5% ice concentration.
A value of 255 is used for false or missing data.
The value 251 represents land.
The same polar stereographic projection and map borders as for the NSIDC sea ice data (http://nsidc.org/data/docs/daac/nsidc0002_ssmi_seaice.gd.html) is used.
The data is calculated by using exactly that projection but for the GEOTIFF format an other ellipsoid has to be used. Some programs like ENVI are not capable of using self defined ellipsoids like the Hughes ellipsoid used by the NSIDC. For this reason the standard WGS84 ellipsoid is used in the GEOTIFF format. This causes errors in the geolocation of up to 500 meter at the corners of the maps. For most applications this should be negligible.
The colortable is adapted from the NIC colortable used for sea ice data (http://www.natice.noaa.gov):
R (red)G (green)B (blue)
0% to 9%00139
10% to 19%30144255
20% to 29%30250160
30% to 39%3413934
40% t0 49%02500
50% to 59%1252500
60% to 69%17325547
70% to 79%2502500
80% to 84%2501250
85% to 89%25000
90% to 95%18685211
96% to 98%1480211
99% to 100%120090
Land (251)100100100
2. Sea ice concentrations as floating point values (hdf format).
Missing or wrong data is marked as NaN (Not a Number) values
using the IEEE standard. The data is stored in the Hierarchical
Data Format (HDF) using the multi-file Scientific Data Set model
(short: HDF SDS file) and has the file extension '.hdf'.
Software to read this data and a lot of additional information
can be obtained from 'http://hdf.ncsa.uiuc.edu/'. HDF SDS is the
standard data format for AMSR data and should be compatible with
the single-file HDF SDS used by the NSIDC for the 'DMSP SSM/I
Daily Polar Gridded Brightness Temperatures'.
3. and 4. Visualization of the data as Portable Network Graphics
(PNG). They have the file extension '.png'. ...
The last two files are more for visualization purposes and not for scientific
interpretation.
---------------end excerpt------------
Did you read the last line of the excerpt?
Did you look for the additional information (where I give an ellipsis)?
Do you know what they're talking about?
Show us your good sense.
Has anyone noticed that the Northeast passage is now open for business?
According to records this hasn't happened before, I think, anyone have any other information on that point?
dhogaza:
> Wanking away at the map is nothing but a DISTRACTION.
Indeed it's a distraction, but it's a good distraction. :)
By playing along with his distraction, we've managed to figure out that his so-called "source code" which does projection corrections is complete vapourware. dipole was trying to pull an Empty Fort Strategy.
The next concept is trickier. Not only is Queensland 'part of' Australia, but there is 'quite a bit left over'. To make this precise I would need to know the projection in use and possibly introduce the associated Riemannian metric. By counting pixels (yay!) and using the area element associated to the metric I could figure out exactly how much was left over.
dipole, this is getting idiotic.
the best way to get that number, is by getting the REAL data. (area: 1,852,642 km² of 7,741,220 km², from wiki)
counting pixels from a map, without having projection details, looks pretty stupid to me. trying to get the information from this particular map (notice the big red lines? notice that black colour inside the map?) would give a FALSE result.
please, stop this nonsense!
http://frwebgate.access.gpo.gov/cgi-bin/getdoc.cgi?dbname=109_house_hea…
Here's Dr. Wegman explaining how he took a hand-drawn curve illustrating a general sense of what was known in 1990 by the IPCC about temperature, digitized it, and considered their numbers proof of a mathematical error ....
"Could we go to figure 5? To further illustrate this, we
digitized the temperature profile published in the IPCC 1990 report
and we did apply both the CFR and the CPS methods to them. The data
used here are 69 unstructured noise pseudo-proxy series with only
one copy of the 1990 profile. The upper left panel illustrates the
PC1 with proper centering. In other words, no structure is shown.
The other three panels indicate what happens when using principal
components with an increasing amount of decentering. Again, the
single series begins to overwhelm the 69 other pure noise series.
Cleary, this decentering has a big effect...."
This is the image they were using (provenance explained at RC)
www.realclimate.org/images/ipcc_1990_panel3.jpg
Fig. 3. The past millennium as shown in the first IPCC report of 1990, before quantitative large-scale reconstructions were available. This curve was based on Lamb's estimated climate history for central England.
Provenance explained at Stoat:
http://scienceblogs.com/stoat/2007/05/tggws_again_again.php#comment-430…
Gerald North explains it was hand-drawn for the 1990 report as an illustration, somewhere in the Inhofe hearing transcripts.
That's from recent history -- one of the great instances of blogging madness based on trying to derive data from an image rather than going to ascertain whether there actually was any data to use.
OK bi and dhogaza #125, #126:
I guess that swooshing sound was the concept of 'quite a bit left over' going over your heads. I know some people have problems with the passage from discrete to continuous quantities, so I will try again.
Bi goes to Bi-Lo and buys (tee-hee) a packet of biscuits. I would like to make a definitive statement like 'there are 12 biscuits in the packet'. But Tim and Hank and Bernard say it's impossible to count biscuits since there are always crumbs left in the packet, or on the carpet, or in bed, so the answer wouldn't be valid.
Dr Meier of NSIDC suspects the count would be inaccurate because of space-time curvature. Now sod is worried we might count the pictures on the packet as real biscuits by mistake.
Anyway, dhogaza comes round for tea and biscuits. After he leaves, bi sees that, unusually, there are some biscuits left in the packet. I claim that it is possible to deduce from this that dhogaza did not eat all the biscuits.
Now I am sure there will be objections, perhaps based on Russell's paradox, or the fact that I haven't given the recipe for the biscuits. But that's the price of hanging out on high class scientific blogs like this one.
Getting back to Mr Goddard's animation:
http://www.youtube.com/watch?v=pgjyNlOGWho
It starts off showing what dhogaza ate, and ends up showing the whole packet. OK - that's entropy violation or something. Just run it backwards. So, did dhogaza eat all the biscuits? Or in this case, did CT show all the ice in August 2007?
Quoted by Hank #128:
The last two files are more for visualization purposes and not for scientific interpretation.
Goddard's expedition was ill-advised, but interesting. I am just amazed how the original story and (nearly) all the posts studiously avoid mentioning the real reason he was wrong - the inconsistency, inaccuracy, or whatever you like to call it, of the CT extent maps in Summer 2007. But so much effort to distract attention from there. It's an interesting group phenomenon. Your link to the README is bad, BTW.
Links with italic can be fixed. You know how to do this.
dipole:
Show us the code.
Show us the code.
Show us the code.
* * *
Hank Roberts:
Perhaps this 'feature' of Deltoid should be disabled, like in some of the other blogs on ScienceBlogs. It's more trouble than it's worth.
Run away and play, bi.
The biscuits are the data. Analyzing the data will be valid.
What you're analyzing is the equivalent of an x-ray photo of the box of biscuits. No matter how good that photo might be, it will never replace the REAL DATA - the number of biscuits in the box, which can be directly counted by opening it and well counting it.
No one in their right mind substitutes an x-ray photo when the box can be opened and examined directly. We only do so when necessary (like, killing someone by removing all their flesh might be extreme).
We just had a recent example in the NFL, where a Giants defensive player hurt his knee. X-rays were negative ("not hurt badly"), and the team was happy. Yet, when they got a better picture (not by flaying the flesh from his skeleton in this case), using an MRI ... out for the year.
The people who generate the maps say "not intended for scientific analysis".
HOW FUCKING STUPID CAN YOU BE?
Let's examine this closely...
The people generating the images say "don't use these for scientific purposes".
Goddard did.
Turns out his analysis was bogus.
We're not ignoring the "real reason he was wrong", we're just pointing out that the people who've made the images said DON'T USE THEM THIS WAY.
You've reached the troll level of idiocy at this point.
I can't believe you're quoting and analysing that last 'argument', dhogaza.
It's not an argument, dipshit, it's a *statement*. By the people generating the maps. They don't attest to the accuracy of them, never had.
Goddard's showing that ... they were right not to attest to the accuracy of them.
Oh my! Earth-shaking news. Climate science is a fraud because a web map, with a disclaimer as to its accuracy, is ... inaccurate!
You're worse than an idiot, dipole. At this point, you are clearly dishonest.
dipole:
When are you going to finish rewriting your vapourware, dipole?
Show us the code.
Show us the code.
Show us the code.
(Oh yes, I did say that
> And according to dipole, he'll have to "rewrite" the [projection correction] code. I wonder how long that'll take? I'm guessing that it'll take forever to rewrite the code, but dipole will mysteriously find enough time to sling mud and play the persecuted Galileo.
and -- no surprise -- it turns out that my prognostications were right! Which means I can now once more call myself a Level XI Junior Goracle, tee-hee.)
dipole, you are clearly wrong. If the maps have a clear disclaimer with them that they are "not intended for scientific analysis", AND there is a link to the original raw data explicitly for the purposes of proper scientific analysis, then your case collapses completely.
Time to ignore any more of this nonsense from dipole, folks.
dhogaza writes:
Amen to that. There's no way I'll ever accept something as fundamentally stupid as astrology.
I'm a Taurus, and we're very stubborn.
BPL said
And that sounds like a load of bullsiht to me. ;-)
meanwhile:
arctic sea ice AREA has gotten incredibly close to the 2007 development.
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg
looks like dipole achieved his mission of distracting us from the real developments..
And, Sod, that graph doesn't run out to september yet. Looks like it's going to cross last year at the next update unless there's a sudden reversal.
Newsflash: Massive Canadian Ice Shelf Suddenly Breaks Up:
http://www.planetark.com/dailynewsstory.cfm/newsid/50087/story.htm
Arctic Melting shows severity of global warming:
http://www.planetark.com/dailynewsstory.cfm/newsid/50081/story.htm
If only this was just about winning on-line debates, and not about the planet turning into one big New Orleans, and not in a good way.
Note the time sequence:
http://instaar.metapress.com/content/645408k4771gj242/
That collapse was one of the remnants:
"Over the course of the last century, the 9000-km2 "Ellesmere Ice Shelf" (82-83°N, 64-90°W) fragmented into six main ice shelves now totaling 1043 km2. This ensemble of thick ice environments ... provides a cryohabitat for microbial communities ....
Environmental Gradients, Fragmented Habitats, and Microbiota of a Northern Ice Shelf Cryoecosystem, Ellesmere Island, Canada
JournalArctic, Antarctic, and Alpine Research
Institute of Arctic and Alpine Research, University of Colorado
Volume 38, Number 4 / November 2006
Online DateTuesday, May 01, 2007
http://news.bbc.co.uk/2/hi/science/nature/7595441.stm
who wants to write some code to compare the ice extents in the two pictures by counting pixels?
z #150 says:
who wants to write some code to compare the ice extents in the two pictures by counting pixels?
I'll save them the trouble. The Markham shelf would be about a quarter of pixel on the CT maps. Out of 30,000 or so.
This guy took the NSIDC predictions of an ice-free North pole this year pretty seriously.
Perhaps he should have counted a few more pixels before he left ;^)
Where did they predict that? Of course, if they predicted an ice-free North pole within 20 years, that would be absolutely no problemo.
This guy took the NSIDC predictions of an ice-free North pole this year pretty seriously.
dipole, as always, is spreading more false information.
the source of this fraud is the original Goddard article in the "the Register":
http://tinyurl.com/5sma3z
Goddard is misrepresenting two scientists, pretending they claim that either the pole would melt in 2008 or even that the complete arctic polar ice cap would melt. (that is what you need, to get there paddling....
here is what they really said:
"We're actually projecting this year that the North Pole may be free of ice for the first time [in history]," David Barber, of the University of Manitoba,... I would say the ice in the vicinity of the North Pole is primed for melting, and an ice-free North Pole is a good possibility," Sheldon Drobot, a climatologist at the Colorado Center for Astrodynamics Research
http://news.nationalgeographic.com/news/2008/06/080620-north-pole.html
the other source is even worse:
"If Norway's average temperature this year equals that in 2007,the ice cap in the Arctic will all melt away, which is highly possible judging from current conditions," Orheim said.
http://tinyurl.com/36yrhh
instead of excusing himself, for the false claims made by him and Goddard, he is still pushing the same false information.
pretty sad person.
dipole:
Show us the code.
Show us the code.
Show us the code.
PS: i couldn t link anyone of them to the NSIDC, but i didn t take a very close look..
but i am sure that dipole provide a detailed account and a good source soon
Chris O'Neill #152:
Where did they predict that?
Here, for example.
It's a 50-50 bet that the thin Arctic sea ice, which was frozen in autumn, will completely melt away at the geographic North Pole, Serreze said.
this was your claim dipole: (#151)
This guy took the NSIDC predictions of an ice-free North pole this year pretty seriously.
now it turns out, they were talking about a 50:50 chance?
if the two of us toss a coin, and i tell you that it is a 50:50 chance for heads, you will claim that i predicted the result to be heads?
how about making a comment that isn t simply FALSE, once in a while?
sod says #157:
If the two of us toss a coin...
Everyone knows a coin toss has 50:50 chance of heads. But when you assign a high probability to some event that is generally thought extremely unlikely then you are making a significant prediction.
Doesn't IPCC make its predictions in terms of probabilities? If they are not predictions what would you call them?
Doesn't IPCC make its predictions in terms of probabilities? If they are not predictions what would you call them?
Try actually learning about the subject.
If you knew the least bit about the subject, you'd know their name.
This has been another public service of the Dano Arguments From Ignorance are Not Convincing and Now Your Mommy is Calling You to Clean Your Room So Go Away and Stop Embarrassing Yourself Network.
Best,
D
Dipole's ignorance makes me smile. To think that cretins like this really imagine that they have a prayer of proving a large number of hardworking professional scientists wrong ...
Dano says #159:
If you knew the least bit about the subject you'd know their name.
I stand corrected. I had no idea the IPCC policed the use of language in their reports so rigidly.
Certainly a very bad example to use.
Dipole, they do a word by word analysis in the final drafting session. So yes, the IPCC does police every word that appears in their reports. Your ignorance is not our problem
Yes, he wanted to take a 50-50 chance. And your point is?
dipole:
I'm still waiting for you to finish rewriting your vapourware which provides Conclusive Proof That Lambert The Warmist Was Wrong™. Or are you simply rewriting it into more vapourware?
Show us the code.
Show us the code.
Show us the code.
Eli Rabett says: #162
Your ignorance is not our problem
All I can say is thanks for filling in this particular gap in my knowledge. I just searched the Garnaut review and sure enough, no use of the word 'prediction' anywhere (in a climate context anyway)!
And I was stupid enough to think these guys were making predictions about future climate. But surely this is not just me? It must be a widespread delusion.
I'm sure I've often heard the term 'prediction' used in the media in connection with the IPCC's work, usually passing without correction. Shouldn't there be a wider education campaign?
Perhaps I will check some of Tim's older posts to see if he is sticking to the party line, or if he might be a closet predictor.
I certainly never meant to cast any aspersions on the efforts of hard-working climate scientists. I was merely standing up for the rights of pixel-counters, an oppressed minority in many parts of the world.
dipole, i appreciate your (at least proclaimed) willingness to learn. but i do doubt that you fully understand this.
the IPCC (and others) is avoiding the term "prediction" exactly because of people like you. people misrepresenting the science. people who ignore the terms "probably" or "50:50 chance" or "might happen" and who are transforming their arguments into false statements, that they then will claim to be wrong.
and the IPPC is not using the term "prediction" for scenarios, because of their structure. they are based on assumptions (changes in human CO2 output, volcanoes, ...) that the ICC does not "predict" but ascertain as a fact for the scenario structure. so the results of such a scenario can t be "predictions".
Thank you dipole, for changing the subject in such an obvious and ham-handed manner. I guess they don't teach rhetoric in Simpletonia.
Best,
D
Sod:
IPCC uses projections, which are outcomes of scenario analysis.
Scenario analysis is used because of the difficulties in predicting the future. Predictions cannot assess emergent phenomena, whereas scenarios can. Unfortunately, the IPCC has done a poor job of explaining to the world what exactly is scenario analysis and their projections. More here.
Best,
D
As the author of comment #157, I think it's you that has the trouble with probability theory, sod.
The Garnaut Review was commissioned by the Aus government to justify introduction of emissions trading. It seems even the authors of that review cannot figure out what the IPCC is talking about:
The (IPCC) decision framework is rarely made explicit, and sometimes is not clear.(p27)
In fact the whole notion of 'probability' makes little sense in this context, and I suspect the IPCC have to invent their own Newspeak so that they can ignore the usual conventions in matters of probability and statistics.
But that's all a bit o/t isn't it? I haven't looked at their use of GCMs, for example, in enough detail to debate the matter with any authority anyway.
I will stick to pixel counting for the moment thanks.
Meanwhile, the NSIDC extent graph has taken another downtick. I'm really starting to think that the flattening out a few days back really was related to our unseasonably cold weather here in western Oregon late last week and Sunday (a strong high is building over the PNW and up into the gulf of alaska and we'll be having unseasonably warm weather the next few days).
Shifting winds, shifting ice ...
It's not at all hard to imagine last year's record being broken in the next couple of weeks.
Dipole's made me smile again ...
dipole:
> I will stick to pixel counting for the moment thanks.
So are you now abandoning your heroic effort to rewrite your projection correction vapourware?
Show us the code.
Show us the code.
Show us the code.
dhogaza #170
Meanwhile, the NSIDC extent graph has taken another downtick.
[snip]
It's not at all hard to imagine last year's record being broken in the next couple of weeks.
If that melt rate continues (more-or-less) then it is only going to take 5-6 days.
I have to admit, the record looks closer to being broken/matched than I thought it would. There's still a very good chance it will remain higher, though, in my opinion. But still... do stoats have sweat glands?
Sweating or not, I think it's a mite bit closer than he thought it would be when he made the bet.
Dipole says (#165)
"I just searched the Garnaut review and sure enough, no
use of the word 'prediction' anywhere (in a climate
context anyway)!
And I was stupid enough to think these guys were making
predictions about future climate."
Dipole, if you'd read the Garnaut report as far as the second paragraph on page one you would not have made that stupid assumption.
doghaza says #170
Meanwhile, the NSIDC extent graph has taken another downtick.
Would that be this one?
2 Sep 4,924,219
3 Sep 4,927,031 (+2,812)
Source
Well, no, after all I said the NSIDC extent graph, and gave a link. Why would you link to something else and ask if that's what I meant?
But you know, dipshit, if you take a nice CLOSE look at the graph you linked to, you'll see it's the same, and shows a steep downtick. It's just harder to see because of the horizontal scale.
Why would you look at graphs when the raw data is available?
Now should you really be saying that Dipole, when here you've been defending someone who looked at fricking pictures of graphs when the raw data was available?
Raw data:
2 Sep 4,924,219
3 Sep 4,927,031 (+2,812)
4 Sep 4,868,125 (-58,906)
And the point of weather trolling is?
Dipole.
You've cocked up with your reliance on distorted image pixel-counting (where's the code?), with your (not) reading Garnaut, and most recently with trying to play clever games with raw data - it took Chris all of four hours to rub your nose in that pile of do-do, and I'm surprised that you didn't anticipate the strength of the trajectory...
I'm calling 'troll' too, and I hope that the thread can be pulled back on-topic, and most especially to the fact that the decrease in the ice extent is ignoring the Denialists' triumphant declarations even a month ago that "it warn't warmin' no more".
Damn that inconvenient integration thing, huh?
Because the plot is a direct graph of the raw data.
Actually it's a running five-day average, but the graph is useful. It's intended to be useful.
The code that does projections is not here,For 'tis just vapourware to provoke fear;And though dipole doth ride the Horse of Gish,Yet Empty Forts can't hide their lack of fish.
07-09-01 +3,907
07-09-02 +6,093
07-09-03 -37,031
07-09-04 -51,875
...and then the negatives continued until the 17th
08-09-01 -72,188
08-09-02 -33,437
08-09-03 +2,812
08-09-04 -58,125
If my calculations are correct, 12 days with an average loss of 28,000 or so will get us to the same point as last year. Average over the last 12 days has been 52,604. My calculations might be wrong, though, because I hate Excel.
Not that I think much of this speculation has any worth. This is weather. It could suddenly change, one way or the other.
I note that the trajectory of the Arctic sea ice extent seems to be starting to plateau several hundred thousand square kms above last year's record low.
I wonder how long before the denialists claim evidence for cooling? Even as they've been holding their collective breaths for the last few weeks...
sea ice area is really really close to 2007.
take a look :
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.365.jpg
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/current.area.jpg
With respect to the Arctic sea ice area, I'd be interested to know what the degree of accuracy is for the measurements, so that the annual difference between maximum and minimum area might be compared over the years.
It seems that this year has seen the greatest loss so far, when considering the winter maximum and the summer minimum.
Will arctic extent cross the the baseline 1979-2000 and produce a positive anomaly? Not happened yet, we currently better than all of the last 5 years and Oct in on the decadel trend which is a nice recovery after 2007.
"http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm"
"http://www.nsidc.org/data/seaice_index/images/daily_images/N_record_ext…"
Yes I know it is not the summer minima, and we have seen predicting the minima even a few months is problematic, but is would still be a excellent.
I have another go at the NSIDC link, but it has gone south the last couple of days.
N_timeseries
I give up after this
N_timeseries
Sean
Sean Egan.
Your point at #190 about the Arctic sea ice extent rising above the 1979-2000 baseline seems to be that such an increase would imply that the climatic regime at the pole is back to hunky-dory on the concern-o-meter, and thus that there would be no further problem. You even use the phrase 'nice recovery' in this apparent context.
The trouble is, if there really is nothing to worry about with respect to melting ice, we should be excited about rises above the baseline only if such occur about as frequently as dips occur below below it. Given that the values for the last seven years of melting have spent rather a lot of the time below the baseline, it would require a majority of the values for the next decade to rise over the baseline for 'a excellent (sic) nice recovery' to be a serious proposition.
If you expect to make a 'hallelujah' announcement as soon as the ice extent trajectory crosses the baseline, you will be ejaculating prematurely in response to noise, and not to signal.
Bernard,
No serious papers are claiming the large number of extinctions so far is due to the warming. Nor is mankind really suffering from the warming at present levels.
However, we both know the climate models suggest the climate will change future, and greens project from this there will in the future be a large number of extinctions due wholly or largely due to warming, and this will add to the present species lose, plus humans in some areas will have less advantage conditions.
So clearly if the ice stops declining, it would be very good news. It is not particularly desirable to turn the clock to a colder climate, even if it ia arguablely a more natural state.
With respect to the Arctic sea ice area, I'd be interested to know what the degree of accuracy is for the measurements, so that the annual difference between maximum and minimum area might be compared over the years.
Bernard J #195
less than we thought. Arctic summer 2008 has been recently been recalculated. Full story at http://wattsupwiththat.com
So, Goddard was wrong, but that's OK. Because even though we've been wrong every time in the past, this time round we're definitely right!
[insert conspiracy theory about ninja inquisitors here]
Bernard Jr, it is not so much how accurate they are as the methodology used. There are a couple of groups that track this and they used different algorithms and get slightly different results. As in many such things the changes are in better agreement than the the absolute amount
Bernard J and Eli Rabett,
It turns out even the changes have little hicks. Tamino has just exposed a issue in how NSICD satellite area records are spliced in a debate with Jeff Id. Seems people, including NSICD forgot to adjust for the polar zone not covered by the satellite, which is not the same between satellites.
Having said that, for area/extent the real changes are way outside measurement error and minor accounting errors.
There is much scope for debate in the depth/volume. You have the Americian sub record which is accurate, but published slowly - not yet showing 2007, and does not go everywhere at the same time. Then you have a satellite which is faulty and is not doing the number of scans hoped for. So there are some good snapshots, but not a continuos film. Not the same part of the cycle each year.
NSCID experts do pull this together. But, if you have to do modelling / make assumptions it leaves wiggle room which is much large than the straight measurement error. So basic questions like is there more or less ice volume today than the same day a year ago, two years ago etc, appear to get
answers with rather limited certainty.
Sean, obviously the answers are good enough for hedge fund work (e.g. comparing each series with itself over time should be pretty good)
There is much scope for debate in the depth/volume. You have the Americian sub record which is accurate, but published slowly - not yet showing 2007, and does not go everywhere at the same time. Then you have a satellite which is faulty and is not doing the number of scans hoped for.
Then you have the denialist dataset, gathered over many years that shows...
Oh, wait. Never mind.
Best,
D
P. Lewis #87,
Thanks for that. I gave up and went to bed. Had to work this morning.
P. Lewis #87,
Thanks for that. I gave up and went to bed. Had to work this morning.
P. Lewis #87,
Thanks for that. I gave up and went to bed. Had to work this morning.