Guest post by Willis Eschenbach
Inspired by this thread on the lack of data in the Arctic Ocean, I looked into how GISS creates data when there is no data.
GISS is the Goddard Institute for Space Studies, a part of NASA. The Director of GISS is Dr. James Hansen. Dr. Hansen is an impartial scientist who thinks people who don’t believe in his apocalyptic visions of the future should be put on trial for “high crimes against humanity”. GISS produces a surface temperature record called GISTEMP. Here is their record of the temperature anomaly for Dec-Jan-Feb 2010 :
Figure 1. GISS temperature anomalies DJF 2010. Grey areas are where there is no temperature data.
Now, what’s wrong with this picture?
The oddity about the picture is that we are given temperature data where none exists. We have very little temperature data for the Arctic Ocean, for example. Yet the GISS map shows radical heating in the Arctic Ocean. How do they do that?
The procedure is one that is laid out in a 1987 paper by Hansen and Lebedeff In that paper, they note that annual temperature changes are well correlated over a large distance, out to 1200 kilometres (~750 miles).
(“Correlation” is a mathematical measure of the similarity of two datasets. It’s value ranges from zero, meaning not similar at all, to plus or minus one, indicating totally similar. A negative value means they are similar, but when one goes up the other goes down.)
Based on Hansen and Lebedeff’s finding of a good correlation (+0.5 or greater) out to 1200 km from a given temperature station, GISS show us the presumed temperature trends within 1200 km of the coastline stations and 1200 km of the island stations. Areas outside of this are shown in gray. This 1200 km. radius allows them to show the “temperature trend” of the entire Arctic Ocean, as shown in Figure 1. This gets around the problem of the very poor coverage in the Arctic Ocean. Here is a small part of the problem, the coverage of the section of the Arctic Ocean north of 80° North:
Figure 2. Temperature stations around 80° north. Circles around the stations are 250 km (~ 150 miles) in diameter. Note that the circle at 80°N is about 1200 km in radius, the size out to which Hansen says we can extrapolate temperature trends.
Can we really assume that a single station could be representative of such a large area? Look at Fig.1, despite the lack of data, trends are given for all of the Arctic Ocean. Here is a bigger view, showing the entire Arctic Ocean.
Figure 3. Temperature stations around the Arctic Ocean. Circles around the stations are 250 km (~ 150 miles) in diameter. Note that the area north of 80°N (yellow circle) is about three times the land area of the state of Alaska.
What Drs. Hansen and Lebedeff didn’t notice in 1987, and no one seems to have noticed since then, is that there is a big problem with their finding about the correlation of widely separated stations. This is shown by the following graph:
Figure 4. Five pseudo temperature records. Note the differences in the shapes of the records, and the differences in the trends of the records.
Curiously, these pseudo temperature records, despite their obvious differences, are all very similar in one way — correlation. The correlation between each pseudo temperature record and every other pseudo temperature records is above 90%.
Figure 5. Correlation between the pseudo temperature datasets shown in Fig. 3
The inescapable conclusion from this is that high correlations between datasets do not mean that their trends are similar.
OK, I can hear you thinking, “Yea, right, for some imaginary short 20 year pseudo temperature datasets you can find some wild data that will have different trends. But what about real 50-year long temperature datasets like Hansen and Lebedeff used?”
Glad you asked … here are nineteen fifty-year long temperature datasets from Alaska. All of them have a correlation with Anchorage greater than 0.5 (max 0.94, min 0.51, avg 0.75). All are within about 500 miles of Anchorage. Figure 6 shows their trends:
Figure 6. Temperature trends of Alaskan stations. Photo is of Pioneer Park, Fairbanks.
As you can see, the trends range from about one degree in fifty years to nearly three degrees in fifty years. Despite this huge ~ 300% range in trends, all of them have a good correlation (greater than +0.5) with Anchorage. This clearly shows that good correlation between temperature datasets means nothing about their corresponding trends.
Finally, as far as I know, this extrapolation procedure is unique to James Hansen and GISTEMP. It is not used by the other creators of global or regional datasets, such as CRU, NCDC, or USHCN. As Kevin Trenberth stated in the CRU emails regarding the discrepancy between GISTEMP and the other datasets (emphasis mine):
My understanding is that the biggest source of this discrepancy [between global temperature datasets] is the way the Arctic is analyzed. We know that the sea ice was at record low values, 22% lower than the previous low in 2005. Some sea temperatures and air temperatures were as much as 7C above normal. But most places there is no conventional data. In NASA [GISTEMP] they extrapolate and build in the high temperatures in the Arctic. In the other records they do not. They use only the data available and the rest is missing.
No data available? No problem, just build in some high temperatures …
Conclusion?
Hansen and Lebedeff were correct that the annual temperature datasets of widely separated temperature stations tend to be well correlated. However, they were incorrect in thinking that this applies to the trends of the well correlated temperature datasets. Their trends may not be similar at all. As a result, extrapolating trends out to 1200 km from a given temperature station is an invalid procedure which does not have any mathematical foundation.
[Update 1] Fred N. pointed out below that GISS shows a polar view of the same data. Note the claimed coverage of the entirety of the Arctic Ocean. Thanks.
[Update 2] JAE pointed out below that Figure 1 did not show trends, but anomalies. boballab pointed me to the map of the actual trends. My thanks to both. Here’s the relevant map:
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Oh dear, I’m going to have to read up on what correlation really means. What I think it means does not correlate with the content in this post!
Great article Willis Eschenbach. Thank you very much.
Why not infill using the satellite data?
I noticed that anomly of T-surf for DJF 2010 is compared to the average from 1951-1980. Isn’t that comparing Arctic temperatures this past winter to a time-period where Arctic temperatures were anomalously cold? Is this 30-year period an adequate era to define this as “average” Arctic temperature? I don’t think so; that would always skew anomalies to “look” positive.
GISS records show a very different pattern on opposite sides of the Arctic. Most of the eastern Arctic was warmer 70 years ago than it is now, while the western Arctic has generally shown a warming trend – at least until the last two years.
Hansen uses the ice age scare time frame as his base temperature, which allows him to paint his maps red and brown.
Just goes to show that if you’re not careful (or don’t care about your integrity) you can probably find what you’re looking for. I think confirmation bias is the proper term for it, right?
Nice work as always Darth Willis the Merciless!
– From one of your loyal Henchpersons ; )
A correlation coefficient as low as 0.5? That’s getting almost as low as some of the coefficients used in social studies. If we had actual data the curves are likely to be radically different.
I got two words for CO2 is AGW…Atmospheric contraction
http://news.bbc.co.uk/2/hi/7794834.stm the point of this first link is the supposition that the ionosphere results as the product of solar energy releases beating up the magnetosphere. When solar flux declines the influence of the magnetosphere grows.
andy adkins (21:27:25) :
(clarifying-emending- the thought experiment)
Examining the climatic record in accordance with the Galactic travels of the earth paint the recent Multi-decadal Temperature changes of the Pacific Ocean as being very erratic and thus symptomatic of a Galactic cold signal.
2. It is a travesty that modern surface temperature records have become political tools that devalue their weather forecasting utility. The curious can find plentiful evidence supporting the conclusion that the most recent warm PDO obscured the ongoing trend to cold. If so there is every reason to expect global temperatures to quickly exceed the cold variances recorded as the peak of the 1940s -70s cold PDO/ cold AMO because the ERBE cold trends will flip the Atlantic’s Multidecadal Oscillation much sooner than previously recorded events (those watching..KNOW that water temperatures in the Atlantic are definitely signaling a capacity for a quick turn).
3. On ERBE: I interpret the temperature analysis work of Spencer and Christy to be an excellent marker of (a) the changes to Earth’s Radiative Budget (1) higher temperatures of the troposphere and stratosphere ar primarily indicators of greater radiative forcing
(b) the water vapor/ precipitation/ cloud cover potentials of the atmosphere summate the atmosphere’s capacity to cool the earth through the processes determining the earth’s radiative budget.
(c) As a response to the increasing gravitational effect had by the sun as an entailment of it retaining more energy during low sunspot cycles (heavier chemical makeup of its core and energy conveyors), High Latitude Volcanic activity increases the density potential of the magnetosphere thereby increasing radiative forcing and the temperature of the stratosphere. To accomplish similar effect, mid and lower latitude volcanic eruptions must (a) be more numerous and frequent (b) be of proportionately greater magnitude
Without going in to detail for those smart enough to have figured it out, understand why the Carrington Event is only a reflex action potential occurrence and why its in process modern sunspot maximum was a joke.
andy adkins (12:37:13) :
P oleward A ccumulating L ava E vents always begin after the winter solstice and follow longitudinal lapping directions toward the new latitudinal summer (oops)
Dear Anu,
When you write
“Similarly, the periodic forcings of the tiny Sun variations in TSI have no longterm effect. Only the inexorable rise of CO2 in the atmosphere have a non-pulse, non-periodic effect on the planets temperature in the 100 to 500 year time frame of interest.” you are being patently ridiculous.
The most important earth bound conditions affecting temperatures are the heights of atmospheric layers. The taller atmospheric layers are then the smaller the rate that radiation is released into space. Contrarily, the shorter that the atmospheric layers are then the higher the rate that radiation is released into space (actually suck the heat right off the earth: You should be scared. Lindzen and Choi proved it). This is as fundament to accounting for why Lindzen and Choi obtained their results as higher latitude volcanic activity -induced by a Heavier Sun- is to increasing the density of the magnetosphere and thus the increasing radiative releases marked by the higher stratospheric temperatures recorded by Christy and Spencer. (If the upper levels of our atmosphere were not warming-increasing energy transfer to space, then the earth would be in a true period of global warming) (Insiders will be mad about me sharing this secret, but when the AGW community use atmospheric warming to justify their conclusions there is a big collective laugh)
As a matter of the simple fact of physics, the warmer temperatures are on earth then the higher the concentration of particular atmospheric gases can be. These physical processes also explain why their is a feedback lag of 800 years between the onset of cold and a fall of in CO2. While oceans are cooling they are still releasing water vapor and this slows the filtering of CO2. (the vikings were chased from Greenland ~ 700 years ago….During the 20th century we clogged our oceans with junk that trawlers can clean up and this detritus is interfering with the absorption of CO2 by the Oceans)
It will surprise the CO2 is AGW community to know that during tall atmospheric conditions (true global warming) CO2 is much less likely to be found near the top…It is just too heavy.
Niels Bohr….CO2 is not a black body…entropy will change the radiation and it will be released and directed in all directions by atmospheric currents and subjected to Earth’s Radiative Budget.
Bad science will kill billions if truth continues to be suppressed.
Just about on topic:
Nenana Ice Classic
The river usually freezes over during the months of Oct. and Nov. The ice continues to get thicker throughout the winter with the average thickness being 42″ on April 1. Depending on the temperature snow cover, wind, ect., the ice may freeze slightly more and then start to melt. The ice melts on the top due to the weather and on the bottom due to the water flow.
River: The tripod is planted two feet into the Tanana River ice between the highway bridge and the railroad bridge at Nenana, just up-river from the Nenana river tributary. It is 300 feet from the shore and connected to a clock that stops as the ice goes out.
Prize: In 1917 railroad engineers bet $800 guessing when the river would break up. Last year, the winners shared the prize money of $303,895. Over $10 million has been paid during the past 92 years. Payoff will be made June 1st, 2009.
This contest surely cannot be accused of fraud. So plotting the breakup time from 1st January you get:
http://img690.imageshack.us/img690/3029/nenanaicebreakb.png
http://nenanaakiceclassic.com/
Not much happens until 1965 when a steady decline begins
Interestingly it shows the early 40s to be warm.
The thing that struck me was the map- Fig 1. Look at Greenland. It looks like the -.5 European anomaly directly borders the +6 Arctic Ocean anomaly – a direct jump of 6 degrees. That’s the nonsense Hansen’s method results in.
Speaking of P oleward A ccumulating L ava E vents that always begin after the winter solstice and follow longitudinal lapping directions toward the new latitudinal summer, are the earthquakes occurring along the North Atlantic Ridge lava burps http://earthquake.usgs.gov/earthquakes/recenteqsww/Maps/10/325_35.php ….Katla could be an uh oh for the atlantic circulation
What is postulated is that a stronger magnetosphere amplifies the gravitational affects that the sun has on the mantle and earth’s core ….and that their stimulation increases their magnetic activity that feeds into a spiraling process of vulcanism and other plate tectonics only made possible by the dynamism of the sun that is made possible by its galactic position.
Hmm, isn’t a common correlation coefficient R-squared? Obviously, this can’t go negative…just between zero and one. Are they using R or R-squared here? If R-squared, then the sentence about correlation going down to -1 needs to be changed.
-Scott
The tree ring circus was extrapolated from one tree? This then may also be close enough. I like the fact they can give us readings to 4 decimal points.
I don’t think you have adequately dealt with inverse correlation. Your explanation sounded funky to me.
Thank you Willis. One of the layers of GISS’s Global Warming layer cake (all covered over with lovely smoothed frosting so we don’t see the cracks and the bits they’ve glued together).
Willis,
Are those Alaska temps NASA GISS “value added” trends or are they raw data trends? If they are raw data trends, has Alaska really been on such a continuous warming trend?
Three hundred, maybe four hundred, years from now Hansen will be hailed as the Michelangelo of Global Climate Change (though I honestly have no idea why –doesn’t ‘climate’ always change, eventually?).
After all, the man is an Artiest. It matters NOT what the people want, or even the College of Cardinals, if the Pope likes baby angels, and big burley men and women, who’s going to argue?
(Hansen could be a lot like J. Edgar Hoover too. Hoover had so much dirt on the crowd in place above him that they were just too afraid to fire him.)
Art and politics, what ya’ gonna’ do? Hopefully, Science will triumph over the darkness of the World, someday.
Dear Willis,
As usual a very sharp observation. But I think you can show the mess more adequately by making the 250 mile circles 1200 mile circles. Then you can show that you can pick nice cherries from a long range of stations, all projecting into the void of the arctic. And I eat my boot if this is not what actually happened. Starts looking for well digestible boots.
Ric,
Correlation – They trend in the same direction. When one goes up the other goes up. That doesn’t however mean that they are going to have the same magnitude or anything close.
Lazy bureaucrats + sloppy logic = garbage in = garbage out
vboring (14:50:54) :
Why not infill using the satellite data?
I believe that, currently, climate monitoring satelites (UAH and RSS) don’t adequately cover the Arctic region above 80 deg North.
Everywhere warm except places where people who might have any contact with reality actually live. It certainly seems as if they rigged the data so that they could declare that the earth warmed, even though exactly none of western civilization participated in the warming. Incredible audacity.
why not use the satellite data and junk the weather station data…. ? What does the 8 yo satellite show… aatsr …….. surely this should settle the matter? or is there a problem with the data fromt that I do find it difficult to read anything on there site! definitely not layman freindly
vboring (14:50:54) :
Why not infill using the satellite data?
Why not just use satellite data?
The issue here IMO is not the lack of stations or even if temperatures are above ‘normal’ or not. The issue is if the anomaly is 0.5’C above normal or 10’C for that matter and normal is -30’C then it is still below F’n freezing. The ice doesn’t care if it is -30 or -29.5. The scary RED blob is all they care about presenting to the gulible masses.