Sunshine hours writes:
I have been a bit worried about the deep deep dive in Antarctica Sea Ice Extent.
It appears to be a processing or sensor error. As of today the NSIDC data confirms it. (see image below)
In a deja vu all over again moment, I find that it isn’t just the Antarctic with wonky readings.
I agree that looks like a sensor failure of some sorts, and this NSIDC graph looks a bit odd as well. NSIDC uses a 5 day average, so the transients get smoothed out.
![S_stddev_timeseries[1]](https://wattsupwiththat.files.wordpress.com/2014/07/s_stddev_timeseries1.png?quality=75)
This Arctic graph from DMI has what appears to be a spurious element also, note the recent uptick:
![icecover_current_new[1]](https://wattsupwiththat.files.wordpress.com/2014/07/icecover_current_new1.png?quality=75)
(added: that uptick could be wind affecting the ice extent, or it could be a sensor/processing issue, we simply don’t know)
Tomorrow there will be a new paper released by former NSIDC scientist Walt Meier and others that tries to argue that some of the record sea ice extents from Antarctica recently are a victim of an adjustment in a processing algorithm that changed in 2007 from Version 1 to Version 2.
Back in 2009, in the “deja vu moment” I wrote:
In the prior thread I raised a question of why there was a large downward jump in sea ice extent on the graph presented by NSIDC’s Artic Sea Ice News page. The image below was the reason, dozens of people called my attention to it in emails and comments overnight because in the space of a weekend, a million-plus square kilometers of Arctic sea ice went missing.
Walt Meier wrote this response that he later had to eat crow for:
Thus errors do happen from time to time and one shouldn’t draw any dramatic conclusions from recent data.
I’m not sure why you think things like this are worth blogging about. Data is not perfect, especially near real-time data. That’s not news.
Now, Meier has an entire paper about such errors, and the error is far lower in magnitude than that incident where the sensor actually did fail and NSIDC was caught napping.
It makes me wonder just how good these estimates of sea ice are; what else awaits discovery?
I wish they’d exhibit the same investigative zeal when it comes to looking at Arctic sea ice record low extents, for all we know, the 2007 low extent might also be a victim of the same algorithm shift that occurred that year.
But you see, confirmation bias prevents such investigations, they expect the Arctic to be low, so they only looked at the Antarctic where there’s more ice than there is supposed to be. To paraphrase their viewpoint on it: “it didn’t look right”.
On the plus side, it looks like this means the AR4 and AR5 reports are wrong about sea ice extent values, and as we know IPCC reports are wrong about a lot of things.
We’ll have that new paper here at 6AM ET tomorrow.
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Reblogged this on Centinel2012 and commented:
It’s very simple if it comes from Washington DC or any government entities don’t believe it unless you personally check it out. NASA NOAA and the EPA are the worst of the lot — all behind the deceitful White House of course.
Wanted
Seesaw psychologist
Experience in bipolar disorder
“This Arctic graph from DMI has what appears to be a spurious element also, note the recent uptick:”
I have to disagree and tweeted about it this am.
https://twitter.com/NJSnowFan/status/491164231904280576
Also I see the connections with large solar TSI spikes and recent slowdown and Pause in Antarctic sea ice growth.
I see what you did there. BiPOLAR disorder? Rofl!
I think the data is accurate . If you watch the AAO the sea ice expands when it is strongly negative and contracts when strongly positive.
I noted that 2010 and 2013 also had the same “uptick” and about the same time. It could be instrumental, but then it would appear to be consistent.
http://arctic.atmos.uiuc.edu/cryosphere/
Shows rapid chances to be common. Look at the graphs from past years. I see nothing much different this year compared to past years.
For my money I bet Antarctic Sea Ice will make another record run with this data now in use.
Did notice that and found quite odd that the 2014 line matches, almost perfectly, the 2013 after the drop. I have been following the trends for some time now and they behave as they are supposed to. There is some similarity in their behaviour, obviously, as these are seasonal trends. But the chances of two set of data matching that closely, after they were apart, are low. Nature tends to behave differently at every step of the way, within a certain range of course, but never the exact same.
I looked to see if I could find any news regarding storms or other phenomena that could have caused such a huge calving but came out with nothing.
The up tick on DMI seems to be the only one with such a steep pitch, thus leads me to believe it is some sort of error. The rest seem to ascertain there is some gain, although they also seem a little on the high side.
As much as I dislike being negative or prone to think there is foul play, I wonder if we are now going to hear some alarmist news regarding this in an attempt to strengthen their dying cause. Somebody is certain to get some funding to research this?
The dmi ‘15% or more ice’ graph uptick Is likely wind.
here is the ice drift and speed for 7/20
http://www7320.nrlssc.navy.mil/hycomARC/navo/arcticicespddrf/nowcast/icespddrf2014071918_2014072000_039_arcticicespddrf.001.gif
There has been two modest low pressure systems; one in the Canadian archipelago and the other just north of Alaska
http://ocean.dmi.dk/arctic/weather/arcticweather.uk.php
This is what I see, just a coincidence???
https://twitter.com/NJSnowFan/status/489444625481216000/photo/1
The simplest explanation for dips and upticks in the extent graph is that the ice can spread out and be crushed back together, (an accordion effect) which makes little difference in the “area” graph but a big difference in the “extent” graph. By comparing the two figures you can get an idea how condensed the ice pack is. While lurking at an Alarmist site I saw they had created a neat area-over-extent calculation that basically measures the percentage of ice-versus-water, and this year the ice pack over the entire Pole is up near 80 %, which is higher than any recent year. (Some consternation at that site.)
Another explanation may be incorrect. (I’m sure someone here will tell me if I am wrong.) However when you run the neat animation (found below the daily map of concentration on Anthony’s splendid Sea Ice Page) of the Naval Research Laboratory ice-concentration maps you can often see the hues of very large areas pale from red to orange or even yellow, and then blush back to red, in a matter of a few days. As this represents a change from 90% coverage to 60% coverage and back to 90% coverage, and it is physically impossible for the ice itself to melt and refreeze to such a large degree so swiftly, some have suggested the satellite sensors get confused by the difference between open water, and melt-water pools. Some even suggest the sensors get confused by slush and wet snow. One person commented they change the sensors from winter-mode to summer-mode to deal with this problem, which creates an artificial dip or upturn in and of itself. Yet another person suggested they look at both Poles with the same sensors, or at least the same sensor-mode-adjustment, so if they switch to summer-mode to look at one Pole it effects the other Pole’s data.
I’d like to learn more about this subject, so if anyone knows more, please inform us amateurs who merely look at charts and maps, with no idea how they come up with them.
http://sunriseswansong.wordpress.com/2014/07/16/arctic-sea-ice-melt-flat-lining-death-spiral/
Perhaps this would be an opportune time to elaborate on how sea ice extent is actually (technically) calculated and how that process has evolved over time?
Little off topic but has to do with Antarctic sea ice. Piece Joe D’aleo did years ago on solar and Antarctic sea oic is on page 259..
http://myweb.wwu.edu/dbunny/pdfs/Chap10Elsevier.pdf
NSDIC News release on July 17 2014,
I did not see it until today.
http://nsidc.org/arcticseaicenews/2014/07/melting-in-the-north-freezing-in-the-south/
Some lunch time results on process and changes. Don’t overlook the FAQ sections 🙂
http://nsidc.org/data/seaice/index.html
http://nsidc.org/data/docs/noaa/g02135_seaice_index/
http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/
njsnowfan says: “Recent solar spikes Match up to the Sea Ice Chart ”
how about you plot those data instead of some vague photoshop artwork. Drawing elispes and linking bubbles is so unscientific it’s hardly worth posting.
Now if you can get some data and plot them both on the same graph so we can see how well it matches and possibly identify any lag between the two, you may be on to something.
I think a lot of climate variability actually _starts_ in the Arctic ( polar amplification is a misinterpretation ). But if you think you have something, go and dig the data and plot it.
I’m not even prepared to be curious on the basis of artwork lash-ups.
Average Arctic Buoys on this site is showing 0C average over the area. Colder then normal
http://imb.crrel.usace.army.mil/newdata.htm
Anthony, would be nice if you could add the 2 these to you Arctic Sea Ice Page..
http://imb.crrel.usace.army.mil/newdata.htm
http://obuoy.datatransport.org/monitor#overview/gpstracks
Oh, furchrisakes! What is wrong with that last post? I can not see anything that is even vaguely likely to trip moderation there.
This site is becoming a PITA to post to. Every second time I post something gets stuck in moderation.
AH, just spotted a finger slip in my login, maybe that’s it.
njsnowfan says: “Recent solar spikes Match up to the Sea Ice Chart ”
how about you plot those data instead of some vague photoshop artwork. Drawing elispes and linking bubbles is so unscientific it’s hardly worth posting.
Now if you can get some data and plot them both on the same graph so we can see how well it matches and possibly identify any lag between the two, you may be on to something.
I think a lot of climate variability actually _starts_ in the Arctic ( polar amplification is a misinterpretation ). But if you think you have something, go and dig the data and plot it.
I’m not even prepared to be curious on the basis of artwork lash-ups.
Some time ago, a commentator claimed that sometime during the [year], there is a need to change the way the algorithm works; something about the angle of the observations creating confusion about what is open water versus ice. I was reading about it shortly before the June dive in the Arctic extent, which seemed odd at the time given the below average temps at the North Pole.
I hope that commentator will weigh in again, especially if they have any insight into what is going on now.
Just a silly pedantic point but “the data is not perfect”….neither is the English – surely it’s the data are nor perfect”?!
ossqss,
I have to laugh at the ridculous PIOMAS propaganda in your link above. Their Arctic chart makes it look like ice cover will hit zero any minute now.
But they never post a graph of the Antarctic. Here is a graph of the Antarctic.
Global ice is at its 30-year average. There is nothing unusual or unprecedented happening. “Ice” is the last, forlorn hope of the alarmist clique. When the Arctic recovers — which it will — what will they have left to get excited about?
What are the chances that two sensors half a world apart have gone “spurious” at the same time?
ossqss says:
http://nsidc.org/data/docs/noaa/g02135_seaice_index/
http://psc.apl.washington.edu/wordpress/research/projects/arctic-sea-ice-volume-anomaly/
Baseline Period Change
What has changed and what has not changed?
The base period used for the Sea Ice Index from 2002 through June 2013 has been 1979 to 2000 (inclusive), a 22-year period. From July 2013 forward, Sea Ice Index products will use a 30-year base period of 1981 to 2010 (inclusive). Data prior to July 2013 have been reprocessed to this new base period.
Monthly and daily ice extent and area data values have not changed, but data and image products that are based on the mean or median have changed. For example, the trend plots may have a different scale, and the value of the slope, expressed as change in percent per decade, has changed, because this value is relative to the mean period.
====
Occording to that, it should not affect ice area and extent.
PIOMAS is a model ( that does not work ) , so the data glitch is irrelevant.
What was your post supposed to indicate?
I agree DB, I was more interested in the process used and altered over time to calculating things. Algorithm changes etc., and last year the change in using a 30 year base period vs the prior 22 year and such. The cumulative impact on output has to have changed quite a bit under the sheets.
One wonders how much the algorithms have been altered by the algorerhythms 🙂
‘This Arctic graph from DMI has what appears to be a spurious element also, note the recent uptick:’
The long term mean also has an uptick about now which, as it survives the smoothing, would seem to indicate that it is a semi-regular occurrence. Perhaps related to geographic features of the basin?