Something odd is going on at the National Snow and Ice Data Center.
Look at this image:
The image is directly from NSIDC’s Artic Sea Ice News page today. Of course there’s the large drop of about 1 million sqkm of sea ice in the last couple of days that is puzzling.
If this were real, we’d also expect to see something also on Cryosphere today plots, and while that group does not do an extent graph, they do make an areal graph. It “should” show something that reflects the drop but instead goes up. WUWT?
While ice extent and area are not exactly the same, they are closely related. So one would expect to see at least some correlation. But we have zero. I suppose there could be a wind issue that is compacting sea ice, but surely there would be something in the area graph.
Something seems not right, and NSIDC owes the public an explanation as they did for a previous drop in extent change from January 15 to 26 which is currently in their Feb 3rd news release.
h/t to Joe D’Aleo and many WUWT commenters.
Again, Walt Meier, thanks very much for your response and concern.
My suggestion would be, if it doesn’t absolutely have to be posted immediately, I’d delay all data postings a couple/few days, to avoid situations like this, if nothing else. If you’re going to check the data over the following days anyway, why not just wait until that check is done and then post it? I know people tend to enjoy instant gratification these days, but haste does make waste 😉
At least Myers responded which adds tons of credibility to heir data. I don’t agree that it should not have been posted here it is actually VIP that it be posted here and is a recognition of “best science blog” Im sure RC would have never posted this?
I don’t know Walt, you’re just not selling it. Here’s what I hear you saying.
“Tsk tsk Anthony. Publicly revealing errors. Mustn’t do that. Did you not learn your lesson by revealing the error which would have been more conveniently ignored concerning the warmest October ever. The proper procedure with errors is to contact the proper bureaucracy where they can be dealt with the same crackerjack efficiency these continual errors in surface station measurements you’ve been reporting on for the last how many years have been.
When you, or your compatriots reveal errors such as “the trouble with Harry”, it allows the great unwashed to leap to the conclusion we the scientific elite actually make them. This is a thing we prefer to keep on QT.”
Now me, if errors are being made, I want to know about them. It leads to striking revelations like how there is no quality control concerning data gathering at GISS.
So keep up the good work Anthony, and thanks to the posters in this thread for all the links to all the other sites allowing updated viewing of Arctic ice.
“Scientists are well-aware of issues using near real-time data and no final conclusions are drawn from such data.”
No I am not employed as a scientist, but I also realize that no final conclusions should be drawn from this preliminary data. I am however a user of your site and, as a taxpayer, I am a contributor as well. Please do not think that your site is for the exclusive use of scientists. The occasional error is to be expected, but know when they happen that they will be posted on the internet, if not by Mr. Watts, then by someone else.
Thanks for your response.
Mike Bryant
Walt, you must admit that your sea ice site and its explanations are decidedly biased towards CO2. A case in point, the very page that explains climate forcings and sea ice completely fails to recognize the very strong influence of ocean decadal oscillations as major (if not THE major) contributors to sea ice change over longer periods of time under the answer to the question: “How do we know human activities cause climate change?” You would look a lot more balanced if you were to include the major contributors to sea ice behavior in your examples of forcings. Certainly you will have to admit that the highly variable Arctic Oscillation and contributing Atlantic Oscillation have a readily verifiable influence on sea ice behavior and by extension, sea ice area and extent. Since you include the questionable affects of TSI in your answer to the question, you are, in my opinion, scientifically bound to include a much more direct and easily demonstrated influence on longer sea ice trends, no?
BTW Walt that wasn’t an overnight error. I’d been watching it for at least a week, comparing it with the graph at AMSRE, and going “What the…”
Just want truth… (18:48:28) :
Secondly, post some sort of disclaimer on the “Daily image update” page of the NSIDC web site, that is easily visible to the casual eye, that small errors could occur in NSIDC data from time to time and that the NSIDC is always working to amend such errors as quickly as can be reasonably expected. Also you could state that the NSIDC knows there will be scrutiny of it’s data, and that you understand the reasons for, and welcome, that scrutiny.
You mean like the ones that’ve always been there in a link immediately below the graph entitled: ‘Learn about update delays’ and ‘Read about the data’
“The daily image update is produced from near-real-time operational satellite data, with a data lag of approximately one day. However, visitors may notice that the date on the image is occasionally more than one day behind. Occasional short-term delays and data outages do occur and are usually resolved in a few days.”
“The daily and monthly images that we show in Arctic Sea Ice News & Analysis are near-real-time data. Near-real-time data do not receive the rigorous quality control that final sea ice products enjoy, but it allows us to monitor ice conditions as they develop.
Several possible sources of error can affect near-real-time images. Areas near land may show some ice coverage where there isn’t any because a land filter has not yet been applied and the sensor has a coarse resolution. Sometimes, the data we receive have geolocation errors, which could affect where ice appears. We correct these problems in the final sea ice products, which replace the near-real-time data in about six months to a year.
Despite its areas of inaccuracy, near-real-time data are still useful for assessing changes in sea ice coverage, particularly when averaged over an entire month. The monthly average image is more accurate than the daily images because weather anomalies and other errors are less likely to affect it. Because of the limitations of near-real-time data, they should be used with caution when seeking to extend a sea ice time series, and should not be used for operational purposes such as navigation.
To look at monthly images that have been through quality control, click on “Archived Data and Images” on the Sea Ice Index.”
“Please note that our daily sea ice images, derived from microwave measurements, may show spurious pixels in areas where sea ice may not be present. These artifacts are generally caused by coastline effects, or less commonly by severe weather. Scientists use masks to minimize the number of “noise” pixels, based on long-term extent patterns. Noise is largely eliminated in the process of generating monthly averages, our standard measurement for analyzing interannual trends.”
Perhaps if instead of rushing off to be the first guy on the block to slam the data provider of the critics should take the trouble to read the readily available background to the data.
Some manual quality control? Goog grief, Walt. You guys wait 2 -3 days to update that graph. Before that is uploaded to the website, all one guy has to do is look at the thing to see if it sticks out like a half milliion km2 sore thumb. That should take maybe one man hour a month. Seems that had the NSIDC done so you would not have had to remove and “look at” the “error” because Anthony brought it to your attention. Perhaps you should pay Anthony to keep a QC eye on the graph!
Is it too much to ask or unfair to expect data that comes out of your agency to have at least more control than that which will be withdrawn and looked at because of one outsider’s comment?
This incident may be spun like much todo about nothing, but my opinion is that it is an important issue which speaks to the credibility of all your data analysis and representation. Much the worse if it turns out the NSIDC claims this not to be an error.
Why?
Glimmer of hope for consensus climate honesty is short-lived
http://www.paulmacrae.com/?p=86
Finally! I thought. The consensus climate scientists who believe, passionately but with almost no scientific evidence beyond computer models, that the planet is warming, that it’s all humanity’s fault, and that we’re heading for oblivion, are willing to admit they’ve been wildly exaggerating the threat of warming to places like the Arctic.
Pope even seemed to agree, noting: Recent headlines have proclaimed that Arctic summer sea ice has decreased so much in the past few years that it has reached a tipping point and will disappear very quickly. The truth is that there is little evidence to support this. Indeed, the record-breaking losses in the past couple of years could easily be due to natural fluctuations in the weather, with summer sea ice increasing again over the next few years.
No, Pope’s target isn’t the anthropogenic global warming believers. Her target is, of course, those evil skeptics, makers of mischief who, perversely, play the same game as Gelbspan and Dotto and Gore.
Sauce for the goose is sauce for the gander, after all. For warming believers, when it’s warming that’s climate, when it’s cooling that’s weather. Another version of this: If it’s warming, that’s human-caused; if it’s cooling, that’s natural variation. Why can’t skeptics play the same game in reverse?
However, there’s no danger of Pope admitting that the AGW hypothesis might be flawed even though, according to the hypothesis, the current cooling should not be happening. Or, at least, none of the consensus climate models predicted this cooling, which is why, to avoid looking completely ridiculous, AGW believers now refer to “climate change” rather than “global warming.” Ironically, though, the consensus models do predict cooling if human influence is removed
Now it appears to be cooling again — something that shouldn’t happen if the consensus climate models are to be believed, but something that might happen if the earth’s climate warms and cools regardless of what humans do.
At the very least, the decade’s non-warming (or cooling) should make consensus climate scientists question their theories, as real scientists do when the empirical evidence doesn’t support those theories.
In truth, the scientific evidence is anything but overwhelming, if the past decade of non-warming is any indication, and anthropogenic warming is still an hypothesis, not a proven scientific fact as Pope would like us to believe. But, then, no consensus climate scientist wants to admit even the teeniest, tiniest possibility that he/she could be wrong. Do that and, even worse than global warming, the research funding and jobs might dry up.
To review: At first sight, Pope’s article appears to be a refreshing call for intellectual honesty from the consensus climate-science camp: “Hey, why don’t we try telling the public the truth, for a change, instead of all this exaggerated alarmism?” After all, as anyone who studies the climate issue with an open mind knows, the Arctic example is only one of hundreds of perfectly natural phenomena that consensus climate science blames on human-caused global warming.
Did Hansen switch government agencies?
How can we know if “data dropouts and bad data due to satellite issues” have or have not resulted in bad plotting since mid January when the trend line started erratically bobbling back to 07?
Phil. (20:05:05) :
Thanks for pointing out the link ‘Learn about update delays’. It in fact led to the following drivel about the “causes of global climate change”…
“Causes of global climate change
How do we know human activities cause climate change?
Fossil fuel burning is responsible for climate change because of the way in which an increased concentration of carbon dioxide in the atmosphere alters the planet’s energy budget and makes the surface warmer.
The most fundamental measure of Earth’s climate state is the globally averaged surface air temperature. We define climate change as an extended trend in this temperature. Such a change cannot happen unless something forces the change. Various natural climate forcings exist. For example, periodic changes in the Earth’s orbit about the sun alter the seasonal and latitudinal distribution of solar radiation at the planet’s surface; such variations can be linked to Earth’s ice ages over the past two million years. Changes in solar output influence how much of the sun’s energy the Earth’s surface receives as a whole; more or less solar energy means warmer or cooler global climate. Explosive volcanic eruptions inject sulfur dioxide and dust high into the stratosphere, blocking some of the sun’s energy from reaching the surface and causing it to cool. These are climate forcings because they alter the planet’s radiation or energy budget.
An increase in the atmosphere’s concentration of carbon dioxide is also a climate forcing: it leads to a situation in which the planet absorbs more solar radiation than it emits to space as longwave radiation. This means the system gains energy. The globally averaged temperature will increase as a result. This is in accord with a fundamental principle of physics: conservation of energy. As humans burn fossil fuels, adding carbon dioxide to the atmosphere, globally average temperature rises as a result.”
The problem is, Walt, that bad or incorrect data is constantly used by AGW scientists to further the agenda. We’ve seen it more often than we can count. Forgive us if we are a little jaded when we see numbers that seem askew. If you hadn’t corrected the problem, “Decreasing Winter Sea Ice Spells Doom” would have been the headline in tomorrow’s NYT.
Dr. Meier,
Were you aware that Cryosphere Today has a product that purportedly compares images from your data for any two days in the satellite era? This product is very misleading and I believe it should be corrected or removed. Please see this overlay along with Steve Keohane’s explanation:
“Regarding another popular depiction of NH ice, I spent a little time on Cryosphere the other day and noticed something odd in comparing 12/20/80 to 12/22/08 NH ice extent. Hudson Bay and the outlet of Ob river in Russia, the boot-shaped inlet next to the arctic, appeared larger in the 1980 plat. I took the landmass/shoreline from 1980 and overlaid it on the 2008 plat, and got this: http://i44.tinypic.com/330u63t.jpg
Please note that I retained the star background in all images, and used their pixels for image registration. At full size, I see no perturbation of those pixels from one image to the other, and therefore assume they are correctly registered.There was no rescaling of any image, no change was made to the pixels, with the exception of tinting Greenland and a few islands blue so they would have contrast when overlaid.”
Here is the Comparison Product:
http://igloo.atmos.uiuc.edu/cgi-bin/test/print.sh?fm=12&fd=20&fy=1980&sm=12&sd=22&sy=2008
I am sure that you want your images to be used properly so that they convey a proper comparison. I have already E-mailed Dr. Chapman:
Dr William Chapman,Can you please explain a couple of things on the Cryosphere Today “Compare side-by-side images of Northern Hemisphere sea ice extent” product, please? Why does the snow in the more recent dates cover areas that were previously sea inlets, fjords, coastal sea areas, islands and rivers? (Water areas, most easily discernible in the River Ob inlet. Why does the sea ice in the older images cover land areas? (Land areas, most easily discernible in River Ob inlet)See this overlay: http://i44.tinypic.com/330u63t.jpg Looking forward to your answer,
Mike Bryant
I have received no response.
I am sure that you do not condone the use of your images and data in this way. I am looking forward to your response.
Thank You,
Mike Bryant
“Phil. (20:05:05) : ”
You must have my comment mixed up with some other comment. You did post a quote from my comment but did not answer what I said. Please look more carefully :
I said :
“that is easily visible to the casual eye, that small errors could occur in NSIDC data from time to time and that the NSIDC is always working to amend such errors as quickly as can be reasonably expected.”
You said :
“‘Learn about update delays’ and ‘Read about the data’”
This does not address what I said. I don’t see “that small errors could occur”. If NSIDC is concerned about not having a reputation for making mistakes then they should act like they are.
I said :
“Firstly, don’t make any data public until you are certain there are no problems such as happened today.”
You say I should have seen this :
“‘Learn about update delays’”
Apparently these delays are from things other than making sure data is correct.
You say :
“Perhaps if instead of rushing off to be the first guy on the block to slam the data provider”
But I had said :
“I hope my comment has struck a friendly tone. I intended it to.”
and in the following comment :
“My previous comment took a while to type and then check over before posting it.” And the long comment I made was the 123rd comment posted in this thread.
So, as you can see I wasn’t trying to slam anyone. I was trying to be friendly. I wasn’t rushing to be the first guy on the block to comment. Actually it took about 45 minutes to make that comment since I had to re-look up the references for what i said.
Everybody needs to visit http://green-agenda.com to see who has an agenda. Read down at least as far as Maurice Strong’s call for the destruction of the industrialized world.
So, is it “the sea ice is” or “the sea ice are”?
Speaking of data sets, why is http://www.swpc.noaa.gov/ftpdir/weekly/RecentIndices.txt still showing January 3rd update? Although it’s called “weekly” it’s actually monthly data. Given that New year’s day was Thursday, and the January update was done the following Saturday, why hasn’t the February update been done as of Feb 17th? Or has that been put off to June 12th as well?
Another data set is now updating. The 1..70 millibar level data at http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/ is now up to DOY:46 (Feb 15th). It had been sitting at DOY:41 (Feb 10) for a few days. Rather annoying to those of us trying to follow the SSW event.
If the data are presented as a moving average, the last few data points will be much more senstive to sampling errors. As more data are filled in, the curve smooths out. This is just a property of moving averages. There may be other explanations, but this one is largely mathematical, will involve later smoothing and does not require an effort to mislead.
People, just chill a bit.
There are at least two things at work here – error correction/QC, and data smoothing/averaging.
First, I see NO delay (not ‘two or three days’) in the posting of data – what we see on the charts is RAW data… why? I assume, because people want the true data right from the sensors, as untouched as possible. Would you prefer they sit on the data for two or three days, adjust as necessary, then post it? Even if you do, there will be just as many people who will point to that and say “AH HAH! You are HIDING something!”
So, either way they’re gonna get bricks thrown at them. I would think their solution is clearly the most scientifically optimal method possible – show the raw data just as THEY see it, but give the proviso that there may be errors until QC checks it, and then refer to those ‘finished’ products.
Yes, some people will ignore the disclaimers and use it to fit their agenda – do you really think that justifies not making the raw data available as soon as possible? Don’t abuse the data yourselves, that makes you just as bad as the ‘other side’.
Second, is the ‘data smoothing’. As I understand it, the previous day’s change may be adjusted away almost entirely, with the last 5 days or so subject to some lesser smoothing.
I watch NSIDC almost every day also… I noticed that over the past two weeks, excluding the last 2 days, that the data has consistently come out a bit below the 2006-2007 line just about EVERY day, but then as it recedes into the few days past, it is also consistently adjusted UPWARDS, so that the end result is that the average is almost exactly the same as 2006-2007. If I really thought there was a conspiracy here, to me it would look like there is somebody that doesn’t want 2008-2009 to look like it is below 2006-2007.
Why either way would be considered an ‘advantage’ to anyone, I have no bluddy idea… unless there is wholesale corruption of the data, the truth will out in a few weeks or month, and then there would be hell to pay (we would make sure of that, yes?) And if wholesale corruption of the data does exist, it has remained hidden for years and none of these comments matter in the slightest.
Finally, the sarcasm is so thick here, it almost seems like entertainment. Does that really make anyone feel better even slightly? Amused? Gratified in some way? There’s enough data here that I find it worth reading, and some may end up providing a truly valuable public service (the climate station audit, for example). But all the snarky comments just make it look like the poster is primarily interested in how the information fits their agenda, rather than truly taking an unbiased look, and following where the data leads.
A final note, in summary:
Be careful what you wish for.
One more thing.
To the person discussing the comparison of February’s or January’s trend charts to December’s, you may be misunderstanding a very important point… A ‘January Chart’ compares ONLY the January averages of past years… i.e., the data sequence is “Jan06, Jan07, Jan08, Jan09”, not “Oct08, Nov08, Dec08, Jan09”. This is obviously done to somewhat remove seasonal variability.
If you already know this but have spotted some other inconsistency, show the charts and let’s all have a look.
Phil. (20:05:05) :
Just want truth… (18:48:28) :
Secondly, post some sort of disclaimer on the “Daily image update” page of the NSIDC web site, that is easily visible to the casual eye, that small errors could occur in NSIDC data from time to time and that the NSIDC is always working to amend such errors as quickly as can be reasonably expected. Also you could state that the NSIDC knows there will be scrutiny of it’s data, and that you understand the reasons for, and welcome, that scrutiny.
You mean like the ones that’ve always been there in a link immediately below the graph entitled: ‘Learn about update delays’ and ‘Read about the data’
“The daily image update is produced from near-real-time operational satellite data, with a data lag of approximately one day. However, visitors may notice that the date on the image is occasionally more than one day behind. Occasional short-term delays and data outages do occur and are usually resolved in a few days.”
“The daily and monthly images that we show in Arctic Sea Ice News & Analysis are near-real-time data. Near-real-time data do not receive the rigorous quality control that final sea ice products enjoy, but it allows us to monitor ice conditions as they develop.
Several possible sources of error can affect near-real-time images. Areas near land may show some ice coverage where there isn’t any because a land filter has not yet been applied and the sensor has a coarse resolution. Sometimes, the data we receive have geolocation errors, which could affect where ice appears. We correct these problems in the final sea ice products, which replace the near-real-time data in about six months to a year.
****************************
Very interesting, Phil. So we shouldn’t rely too much on this data till it goes through “rigorous QC”, which lags the error ridden (as we have seen and Walt has cautioned us about) “near real-time” data by 6 months to a year! I wonder whether NSIDC newsworthy status reports take this into account…
http://nsidc.org/arcticseaicenews/
“As is typical during mid-winter, sea ice extent increased overall in January; maximum monthly extent is expected in March. However, January ice extent remained well below normal compared to the long-term record. Ice extent averaged for January 2009 is the sixth lowest January in the satellite record. Also of note is that from January 15 to 26, ice extent saw essentially no increase; an unusual wind pattern appears to have been the cause.
Arctic ice extent averaged for the month of January was 14.08 million square kilometers (5.43 million square miles). ”
Not 14.07 or 14.09. Not newsworthy? Oops. “Several possible sources of error can affect near-real-time images.”… “We correct these problems in the final sea ice products, which replace the near-real-time data in about six months to a year.”
“I see NO delay (not ‘two or three days’) in the posting of data – what we see on the charts is RAW data…”
Wrong on both accounts.
“The daily image update is produced from near-real-time operational satellite data, with a data lag of approximately one day.”
http://nsidc.org/arcticseaicenews/faq.html#update_not_current
“The daily image update is produced from near-real-time operational satellite data, with a data lag of approximately one day. However, visitors may notice that the date on the image is occasionally more than one day behind. Occasional short-term delays and data outages do occur and are usually resolved in a few days.”
Often the chart will not be updated for 2 or 3 days. This is evident in today’s update and subsequent removal. And the data is not “raw” but the result of running raw data through program algorithms (“produced from” above).
Just curious- since the discussion here has been one concerning the graphed data, can anyone shed light on the apparent massive breakup of ice in the image data corresponding to this? See:
http://nsidc.org/data/seaice_index/images/daily_images/N_daily_extent_hires.png
[NOTE: for future reference, this link is to a continually updated image- the image referred to will shortly no longer be available on this link, and if representing a corrupted data set, as I think, will likely no longer be available anywhere.]
The areas in question are around the Bering Strait, the Gulf of St. Lawrence, Hudson’s Bay, and other sea areas to the North of Canada, as well as an apparent smattering across the whole of the western Arctic.
See the Dec. 2008 image for comparison:
http://nsidc.org/images/arcticseaicenews/200901_Figure1.png
I suspect that the image captures the data failure very well, as it seems impossible that this is an accurate representation of reality. If the graphed data corresponds in some at least semi-automated fashion to what is represented by the image, as one must assume, then the image appears unequivocally to show a significant data failure. Or can Hudson’s Bay really be suddenly in the advanced stages of breakup, halfway through a particularly cold February?