Guest post by Willis Eschenbach
A few days ago, Steve Goddard put up a post called “Does PIOMAS Verify?” In it, he compared the PIOMAS computer model estimate of the Arctic ice volume with the SIDADS satellite measured Arctic ice area. He noted that from 2007 on, the two datasets diverge.
Intrigued by this, I decided to compare the PIOMAS ice volume dataset with the Cryosphere Today (CT) Arctic ice area dataset. Here is that data:
Figure 1. Arctic ice area (red line) from Cryosphere Today. Black line is a 6 year Gaussian average.
When I compared the two datasets, I expected to find something curious happening with the PIOMASS dataset. Instead, I found a puzzle regarding the CT dataset.
I compared the CT area dataset with the PIOMAS dataset, and I found the same thing that Steve Goddard had found. The datasets diverge at about 2007. So I took a hard look at the two datasets. Instead of an problem with the PIOMAS volume dataset, I found the CT area dataset contained something odd. Here is a plot of the CT daily data with the daily average variations removed:
Figure 2. Cryosphere Today daily ice area anomaly. Average daily variations have been removed.
The oddity about the data is what happens after 2007. Suddenly, there is a strong annual signal. I have put in vertical black lines to highlight this signal. The vertical lines show the end of September of each year. Before 2007, there is only a small variation in the data, and it does not have an annual signal. After 2007, the variation gets large, and there is a clear annual aspect to the signal. The area in September (the time of minimum ice) is smaller than we would expect. And the area in March (the time of maximum ice) is larger than we would expect.
I considered this for a while, and could only come to the conclusion that there was some kind of error in the CT dataset. So I decided to look at another dataset, the NOAA SIDADS dataset.
Again, I removed the monthly signal, leaving only the anomaly. Here is that result:
Figure 3. SIDADS monthly ice area anomaly. Monthly variations have been removed.
Again we see the same oddity after the start of 2007, with a large annual variation where none existed before 2007. In the SIDADS dataset the variation is even more pronounced than in the CT data.
So that is the puzzle. What has changed? Are they using a new satellite? If so, has the changeover been done properly? Since the smallest of the data has gotten smaller and the largest of the data has gotten larger, is the average data still valid? Just what the heck are we looking at here?
Despite searching, I have not been able to find the answer to this question. However, I have great faith that the assembled masses of the WUWT readership will find it very quickly. (And then some of the readers will likely tell me that this shows I am a layman and a fool, and that I should have been able to find the answer easily on my own … so sue me.)
Of course I would isolate ring of fire issues.
and never forget………………….
http://www.youtube.com/results?search_query=locomotion+kylie+minogue&aq=1
Thats hot .
Tom P says:
June 1, 2010 at 3:11 am
[–snip–]
Volume 12, Issues 3-4, 2006, Pages 401-415
From the abstract:
“We show that the amplitude of the seasonal cycle of sea ice extent increases in both hemispheres in a warming climate, with a larger magnitude in the Northern Hemisphere. Furthermore, it appears that the seasonal cycle of ice extent is more affected than the one of ice volume.”
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All of that would be true for one reason, and one reason only: There is more land mass in the northern hemisphere, and as a result of the nominal heating of that land mass by the sun, the Arctic areas would be more affected as a result.
Additionally, and which isn’t even mentioned —much less broached— is the fact of the oceanic currents, themselves which are products of the Earth’s rotation.
The signal you’re seeing is due to delayed re-freezing in 2007/2008/2009.
In each of these years, the unprecedentedly low summer ice minima mean that open water remains for longer. Thus, the anomaly relative to long-term trends is actually highest in October, well after the minimum itself – in previous years the re-freeze is well under way by this point, whereas in 2007/2008/2009 the re-freeze was only just starting.
Thus, for these three years, not only is the overall minimum lower each summer, but the overall *shape* of the curve is different – remaining low longer into the autumn.
And then —of course— there’s been all that logging going on in Siberia …
Certainly that would raise the heat level, wood it not?
Shouldn’t the anomaly be zero when the ice extent was the same as some average (1979-2000, 1972-2008, whatever) ?
e.g.:
http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seaice.anomaly.arctic.png
Figures 2 and 3, above, should be ± with respect to some zero anomaly.
Isn’t the most likely cause a change in instrumentality or recording procedures? — Always review the source, before trying to draw conclusions.
And who can do this best? A complete audit should be in order.
899 says:
June 1, 2010 at 5:07 am
Yahoo!
Someone has finally clued into Planetary Mechanics!
ROTATION
Should “monthly” be “daily” as for the preceding graph?
Is It possible that we are looking at variations in NEW ICE (thin) vs. MATURE ICE (thick) melt rates? If so, I would expect to see the variations damp out over time.
Also, Stephen Wilde may have some thoughts related to hemispheric jet stream winds, the AO and SOI, effects on ice movement and formation rates.
Just thoughts.
DavidS says:
June 1, 2010 at 3:52 am
The alarmists were right!
http://arctic.atmos.uiuc.edu/cryosphere/NEWIMAGES/arctic.seaice.color.000.png
PS. In my browser the image is showing no ice at all.
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Yeah, amazing that, eh? Yet just south of the pole there’s ice …
Go figure.
Increased winter ice extent with falling summer extent just doesn’t make physical sense. If there is increased open water area in the summer months, then solar heat accumulation in the Arctic Ocean would increase, and so tend to delay the formation of winter ice, not promote it. More likely there is some change in how the data is being processed that causes an increase in the reported seasonal variation.
899 says:
June 1, 2010 at 3:12 am
So Willis, what was the Sun doing in 2007?
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Here is the Cycle 23 graph. http://spacemath.gsfc.nasa.gov/weekly/3Page35.pdf
Cycle 23 which was smaller than Cycle 22, peaked in the year 2000 and had hit minimum in 2007. The peak was between 125 & 150 for about two years & spiked to 175.
The earth’s geomagnetic field at the north pole has dropped too and the magnetic pole has wandered.
http://www.vukcevic.talktalk.net/SSN-GMF.gif
The Polar field strength goes “below average” as of year 2000
http://www.vukcevic.talktalk.net/LFC24.htm
Multiple Rifts In Earth’s Magnetic Shield
Solar geomagnetic activity is at an all time low
“New Paper”: solar magnetic variation initiates interglacials
The reason I mention the magnetic fields is because of the interaction with cosmic rays.
Graph of cosmic ray count from 1965
For those new to WUWT the theory of cosmic rays/clouds/climate:
Did cosmic rays cause ice ages?
J. D. Lindskog says:
June 1, 2010 at 5:26 am
Is It possible that we are looking at variations in NEW ICE (thin) vs. MATURE ICE (thick) melt rates? If so, I would expect to see the variations damp out over time.
Well, look at the last three years of the top chart above. The tops are basically level but the bottoms are increasing year to year. There’s your dampening in action! If you didn’t already realize that, then you have a pretty good physical sense.
paulo arruda says:
June 1, 2010 at 4:31 am
For the fourth time cold arrives in Amazonia. Usually there are fewer episodes per year lasting 1-2 days. This “chill” lasted five days.
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Paulo, did you guys steal our arctic ice to cool off the Amazon? Tisk, tisk.
Maybe this is what the sea ice area looks like at the beginning of a trend toward increase.
The ceiling moves up before the floor follows.
That’s just a NSWAS I made up. But it has as much support as anything I have read in these comments.
Though some disagree with the claim that the Sun did it, because the “effect” of solar variation is too small, any variation can have an effect over time if it is the biggest kid on the block. SC21 – SC23 were of sufficient variation and the variation was adequately cumulative to cause the variation in climate and polar ice that we have seen of late in this little piece of rock we call home. The very little time that we have tracked solar variation, a’la Sunspot’s and Radio Flux and Ap Index, etc., etc., is indeed miniscule. During that time, what precisely has happened to Mother Earth? She was in and came out of a mini-iceage. She got warmer. And warmer. And warmer.
How? TBD- Everyone has a “special” how-it-happened opinion. Bottom line: We need to wait and see. Few, if any of us will be around when a real scientist gets a real Knoble Prize for the real discovery I’m sure.
If we’re taking another dip (or NOT) in global temperature readings –as in another Little Ice Age– we’ll probably know something for sure in about 200 years. In the mean time, hold on to your seats sports fans, you’re going to see everything from American droughts to European flooding to Asian blizzards and African cyclones and Amazon mega-gushers and mountain glacier growths and retreats, and every variation thereof, like you’ve never seen before. Well… you will if you care to watch. It’s a real slow and boreing process.
PS: The signal variation is curious indeed.
This illustration is the best way to visualise the “new” seasonal signal.
http://arctic-roos.org/observations/satellite-data/sea-ice/observation_images/ssmi1_ice_area.png
Here you have the yearly melt curves for 2007/8/9 and also the average across the historical record. The anomaly is the *difference* between the average and the actual yearly data.
Check out 2007, moving from September into October. The low ice extent leads to increased heat absorption by the open ocean and a delay in the re-freeze. Thus, for 2007 the extent at the start of October was almost the same as at the start of September. In contrast, when you look at the average data, there is usually substantial re-freezing by the start of October. Thus, the *anomaly* increases throughout September and peaks in early October, well after the actual ice minimum.
This same phenomenon (deleyed re-freeze) occurred in 2008 and 2009 – you can measure it yourself from the graph if you want and see how the slower re-freeze leads to an increase in the anomaly. It will happen on any year where the summer minimum is substantially below average, for well-understood physical reasons. It just so happens that in the Cryosphere today data set, this only applies to the last three years – because these were the three lowest years on record for summer ice!
Malaga View says:
June 1, 2010 at 4:41 am
tarpon says:
June 1, 2010 at 5:21 am
“Isn’t the most likely cause a change in instrumentality or recording procedures? — Always review the source, before trying to draw conclusions.
And who can do this best? A complete audit should be in order.”
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Magic Java had already answered your question. Yes there was an instrument change. A channel failed and now is “synthetically created” that is they make up the data.
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http://magicjava.blogspot.com/2010/04/three-valued-logic-and-irreproducible_29.html
“Example: Aqua Satellite Channel 4 Virus
It helps to have an example, so we’ll be using channel 4 of the AMSU on the Aqua satellite. Channel 4 failed completely around December, 2007. In response to this, NASA created a new algorithm and has used it to synthetically create channel 4 data from October 1st, 2007 onward.”
Maybe the experience of this scientist is relevant:
Interesting… 2014, 2012, 2029, 2100. Those dates don’t matter. Arctic sea ice might disappear in the summer, but not anytime soon, and it wouldn’t affect sea levels enough that anyone would notice. I think the polar bears will do OK too.
Cryosphere is a strange word. I believe there has only been one time when the earth was even close to being a sphere covered with ice, thankfully that was way back in the PreCambrian.
The ice is topologically no more than the equivalent of a couple of bits of orange peel.
paulo arruda says:
June 1, 2010 at 4:31 am
For the fourth time cold arrives in amazonia. Usually there are fewer episodes per year lasting 1-2 days. This “chill” lasted five days.
Paulo, so you finally feeling it down there! Bout time! You probably look at it as a great cool break. But as the warmists insist, that cool is not climate, that’s weather, warm is climate. 🙂
Providing the data hasn’t change to any significant degree, my guess would be that the changes are caused by ocean current thermal lag effects and changed wind patterns. Both of these being effected by the transition from a highly active to a quiet sun.
Perhaps this change will lead to a recovery of Arctic sea ice, which has been in decline since the start of the 80’s. We do not have a sufficiently long record of sea ice cover to know whether this is a new phenomenon or not or how it relates to longer term climate quasi-cycles.
1410-1500 cold – Low Solar Activity(LSA?)-(Sporer minimum)
1510-1600 warm – High Solar Activity(HSA?)
1610-1700 cold – (LSA) (Maunder minimum)
1710-1800 warm – (HSA)
1810-1900 cold – (LSA) (Dalton minimum)
1910-2000 warm – (HSA)
2010-2100 (cold???) – (LSA???)
Trivial. Think about it a bit more or look here
http://www.scienceblogs.de/primaklima/2009/06/die-mar-vom-rasend-schnellen-meereiswachsen-und-dem-was-die-modelle-vorhersagen-teil-ii.php
The models show it as well, but of course later.
Willis, this is interesting.
The loss of thick multi-year ice in 2007 reduced a buffering mechanism which tended to stabilize the numbers prior to 2007. Thick ice acts somewhat like a low pass filter. As the ice thickens again, we should expect to see less intra-annual variation in the future.
Gail Combs : June 1, 2010 at 5:53 am
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Most significant correlation I found is shown here:
http://www.vukcevic.talktalk.net/NFC1.htm
The transfer mechanism is not known, but it may be something to do with a ‘Svensmark type’ effect.