The GISS Temperature Record Divergence Problem
Guest post by Tilo Reber
“Areas covered occasionally by sea ice are masked using a time-independent mask.”
So if there is sea ice coverage for any part of the year, GISS will not use SST values to cover those cells for the entire year. Those cells must be covered by extrapolations from land for that year. This means that when the area is cover with ice or with water or with part ice part water, it will have it’s anomaly extrapolated from land, regardless. HadCRUT, on the other hand, does not extrapolate their coverage. But they will use SST values for a cell when SST values are available for part of the year. If the area is covered with ice for the entire year, HadCRUT will not assign it a value. Therefore we get polar areas that are covered by extrapolation by GISS and not covered at all by HadCRUT.
When we look at the HadSST2 record, we see that the cool cells that show up above Svalbard in 2005 are consistent with the numbers in that record. And these then go into creating the sea surface portion of the HadCRUT3 temperature record. So, obviously, how cells are filled with data can have a profound effect on the anomaly value that those cells have. This leads one to wonder if extrapolations at the pole are legitimate. I decided to look at some of the northern Russian stations, at the GISS site, that show up as being so hot in the 2005 version of the GISS chart when compared with the 1998 version of the chart. I found that those big changes are in fact represented in the individual records – especially for the coastal stations. Here are three of them.
1998 Annual Mean – -3.39
2005 Annual Mean – 0.60 1998 – 2005 delta 3.99 C
1998 Annual Mean – -14.99
2005 Annual Mean – -10.79 1998 – 2005 delta 4.2 C
Gmo Im.E.K F: 77.7 N, 104.3 E.
1998 Annual Mean – -15.96
2005 Annual Mean – -12.67 1998 – 2005 delta 3.29 C
For comparison, let’s look across the Arctic ocean and see what was happening in Canada and Alaska at the same time.
Eureka, N.W.T.: 80.0 N, 85.9 W.
1998 Annual Mean – -17.38
2005 Annual Mean – -17.34 1998 – 2005 delta 0.04 C
1998 Annual Mean – -8.80
2005 Annual Mean – -10.44 1998 – 2005 delta -1.64 C
So it seems that the North American side of the Arctic changed little, or even got cooler between 98 and 05, the Russian side warmed considerably. Why is that? I think that this ice cover map gives us the answer. As is immediately apparent, the coastal ice cleared out far earlier in 2005 in northern Russia than it did in 1998. This is even though the rest of the globe was slightly warmer in 1998 than in 2005. When dealing with coastal stations, removing the ice and exposing the water is like taking the hatch off a heating source for the coastal thermometers. For stations that are in areas where the temperature is well below zero, exposing the immediate area of that thermometer to a surface that is above zero, changes everything. Looking at Ostrov Vize, we see that it is a small island, and therefore even more subject to changes in coastal sea ice. And when we compare 1998 months on this island with 2005 months we can see that there are differences in some of the monthly means that are larger than 10C. Even a partial ice cover as opposed to a complete ice cover will supply the stations with more heat.
So I think that we can safely say that the huge change in the anomalies of Russian coastal stations is mostly due to coastal sea ice changes. In fact, if we look at stations further inland in Russia, the coastal effect begins to decline. With this in mind, we need to ask if the GISS extrapolations of land based stations, particularly coastal stations, to the poles is appropriate.
The answer would seem to be that it is not, and the Svalbard case makes this perfectly clear. There we had a case where the SST anomaly was actually cool, and yet the land based extrapolation actually turned those sea based cells more than 3C hotter. Reaching across the Arctic Ocean with temperatures that are the result of a coastal sea ice effect cannot give valid answers for what the temperature anomalies away from those coastal stations should be. In fact, taking the variation that is represented by those coastal stations and extrapolating into the interior of Russia is also not appropriate, because the interior areas did not undergo the magnitude of temperature change of the coastal stations.
Looking at the SST temperature anomalies that NOAA uses for 1998 and 2005 it again looks like nothing exceptional was happening in the Arctic (Note, the chart will not retain the months that I selected; so use your own sample months and they will plot). It seems, from this analysis, that GISS polar extrapolations and interpolations are likely to simulate large variations away from the Arctic coasts that are really only present as changes at the Arctic coasts. And the GISS divergence from HadCRUT, as well as from UAH and RSS are likely to be errors instead of enhancements.
Tilo,
Well in the US, Africa, SA, and Europe, basically all the land masses in both the 2005 and 1998 maps, The GISSS is definetly warmer by a large degree than the HaDcrut. You don’t know why? Seems odd there can be that much difference in the land mass temps. John.
Noticed that Hansen’s printer seems to have a developed a red bias recently.
Here’s a tip Jim! Change the f***ing cyan cartridge!!!
Sometimes I, somewhat cynically, wonder whether Hansen won’t be happy until the entire map is extrapolated from one thermometer situated in his office… next to the A/C vent.
Perhaps I am growing somewhat intolerant with age…
re the post by davidmhoffer
I’m not a physicist or even a railway engineer. I put into the vernacular aspects of science and technology. I really enjoyed your dialogue and I think Galileo would have too. It reminded me a bit of Lewis Carroll.
carrot eater:
Omitting the Arctic in effect means that you are setting it to warm at the exact same rate as the global mean, which appears unlikely. Perhaps the truth is somewhere in between the two data sets.
Your question is valid. Just for something quick and dirty I decided to plot the Amundsen-Scot sation at the south pole. It’s one data point that should be removed from too much of a sea ice effect and that should have a maximum CO2 polar effect. Oddly enough it shows about -0.2C of cooling over it’s 52 year period. But we can’t conclude too much from one station.
I suspect this means that if the ice extent expands again, there could be a sharper drop in the GISS global temperature than in other data sets. Right?
Quote: Leif Svalgaard (12:08:57):
“Not that I’m mounting a defense of his method, but . . .”
Yes, Leif. Of course not.
With kind regards,
Oliver K. Manuel
>>
davidmhoffer (13:42:55) :
An external energy source radiates 1365 watts per meter squared at it on a constant basis.
<<
Actually the TOA TSI varies with the Sun-Earth distance (assuming a constant solar output) from about 1321 W/m^2 (just after July 1st) to about 1414 W/m^2 (around January 1st). The 1368 W/m^2 value is the average (at about 1 AU or the semi-major axis distance of the Earth’s orbit).
Jim
Roger Knights:
I suspect this means that if the ice extent expands again, there could be a sharper drop in the GISS global temperature than in other data sets. Right?
That should be what happens. I think I can give you an example of that. Take a look at the GISS 98 chart in the article above. Notice that there is a cool Arctic area that has been extrapolated above Russia. Now look at this chart:
http://3.bp.blogspot.com/__VkzVMn3cHA/SDtWvmPzrVI/AAAAAAAAACU/1xl7LBESwbs/s1600-h/Ten+Year+Divergence.bmp
Keep in mind that the different temp sets have different baselines. But you can see that GISS is higher almost everywhere. Now look at it in 98. It’s level is the same as the others and possibly lower. It’s an exercise in eyestrain, but it’s also an indication that the reverse effect applies.
Tilo: Using that mapping features of the KNMI Climate Explorer, I created a few .gif animations for 1998 and 2005, North Polar view (north of 50N), to compare GISTEMP to HadCRUT3+HADSST2 and to compare GISTEMP to the SST dataset GISS uses, which in 1998 and 2005 was the NCDC’s OI.v2 SST data (not the ERSST.v3b data you linked in your post). I also made the base years for anomalies 1998 to 2005. Seemed appropriate.
Something to consider, though. KNMI does not provide HADCRUT3 data. KNMI uses HADSST2 and CruTEMP3 data and merges them themselves because:
http://climexp.knmi.nl/crutem3_hadsst2.html
Other than that the data should be similar. Keep in mind that the polar view skews perspective as the distance from the pole grows.
First animations are of GISTEMP (1200 km smoothing) vs OI.v2 SST anomalies. The GISTEMP smoothing does overwhelm the SST data, but is it significant? Dunno.
GISTEMP vs OI.v2 SST anomalies 1998:
http://i49.tinypic.com/1198nsy.gif
GISTEMP vs OI.v2 SST anomalies 2005:
http://i49.tinypic.com/1gpzic.gif
Next I compared GISTEMP (1200 km smoothing) to the combined HadCRUT3+HADSST2. Note how sparse the Hadley Centre data is over Siberia, parts of Northern Canada, and Greenland.
GISTEMP (1200 km smoothing) vs HadCRUT3+HADSST2 1998:
http://i47.tinypic.com/21o69vq.gif
GISTEMP (1200 km smoothing) vs HadCRUT3+HADSST2 2005:
http://i49.tinypic.com/2lc0axu.gif
This raised the question, is GISS infilling all of the areas missed by the Hadley Centre? The answer is no. To view this, I compared GISTEMP (250 km smoothing) to the combined HadCRUT3+HADSST2 In 1998 and 2005. GISS’s geographic coverage was much better than the Hadley Centre’s. However, keep in mind that the polar view skews perspective with distance from the pole, and the latitudes I illustrated are much greater than the Arctic.
GISTEMP (250 km smoothing) vs HadCRUT3+HADSST2 1998:
http://i47.tinypic.com/9867nm.gif
GISTEMP (250 km smoothing) vs HadCRUT3+HADSST2 2005:
http://i49.tinypic.com/11t4b3c.gif
While this doesn’t provide an answer for the difference between the two datasets, it provides a different perspective.
Also, I have shown that, by comparing GISTEMP and UAH MSU TLT data, the GISS infilling with the 1200km smoothing does add a significant positive bias in parts of the world with sparse surface station coverage, specifically Africa, Antarctica, Asia, and South America:
http://bobtisdale.blogspot.com/2009/06/part-2-of-comparison-of-gistemp-and-uah.html
Does the GISS 1200km smoothing also add a positive bias the Arctic, when compared to UAH MSU TLT anomalies? Yes:
http://i43.tinypic.com/1zp1q8j.jpg
And that graph is from this post:
http://bobtisdale.blogspot.com/2009/06/part-1-of-comparison-of-gistemp-and-uah.html
Regards
Re: John Finn (Jan 29 13:30),
UAH NoPol readings show 2005 ~0.74 deg warmer than 1998 and a linear temperature increase of ~0.6 deg over the 8 year period. There has also been more summer ice melt since 2000. GISS are probably closer to the true picture than Hadley.
John Finn,
The numbers are:
NoPol
2002-2009……….land………………ocean…………land/ocean
…………………… -.17c/dec…….. .0006c/dec……. -.10c/dec
2005-2009……….land………………ocean…………land/ocean
………………….. -1.27c/dec……. -1.14c/dec…….. -1.22c/dec
Hansen is making up temperatures where none are measured. Satellite at least does even if it isn’t 100% coverage of the Arctic. It really is amazing the extent to which some go to defend the indefensible.
Somehow, I seriously doubt that Hansen’s extrapolation was an error.
Remove the Arctic Ice Cap and replace with slush.
Switcheroo.
That is surely the basis for the very strong argument that a lack of polar sea ice is a negative ‘warming’ feedback as more heat is lost when there is no ice.
Punxsatawney Phil (16:15:12),
Yes, on average everyone has less than two legs.
JEROME:
“That is surely the basis for the very strong argument that a lack of polar sea ice is a negative ‘warming’ feedback as more heat is lost when there is no ice.”
If that’s true, then less ice should mean stronger currents. That would be interesting to look into. Of course the reverse side is that more ice means more albedo means less heat is gathered. I’m not sure which is the stronger effect. But a negative feedback does seem possible.
bryan (14:40:22) :
I could be wrong, but I believe they moved the reporting station in Death Valley to Badwater which is a ‘hot spot’. All to the good eh?
DaveE.
@ur momisugly Tilo Reber (12:23:54) :
“Roger, look at the ENSO transition that happened right around 1977. Both before and after.”
First, Tilo, this is an excellent article and thank you for writing it.
Second, as to the ENSO transition in 1977, that is precisely the point – or perhaps entirely beside the point. Whatever caused the colder winters, there is no doubt they did occur. The simple statistical effect from having 1975 as the starting point that alarmists use to show the globe has warmed, with a string of cold winters immediately after that starting point, is all that was required to create global warming. This is a well-known statistical effect, that is, the undue influence on a trend line of starting and ending values in a data set.
Other known effects can explain warmer summers in those cities that show hotter summers and warmer winters, such as Urban Heat Island effect due to increased population, and increased humidity in formerly desert cities such as Tucson and Phoenix in Arizona, USA.
The evidence all leads to one inescapable conclusion: CO2 is not the cause of any changes in the earth’s average global temperature. The entire premise of man-made global warming due to fossil fuel consumption is absolutely false.
Actually the TOA TSI varies with the Sun-Earth distance (assuming a constant solar output) from about 1321 W/m^2 (just after July 1st) to about 1414 W/m^2 (around January 1st).
I actually knew that, but adding it as a variable to the artificial intellgence model caused the simulation of the physicist to increase output verbage by an order of magnitude as he had to include that variable’s effect on each answer to the climatologist. As the end point feedback corruption loop didn’t seem to be affected one way or another, I took it out. There was one outlier however where the climatologist interrupted and insisted that the earth did not in fact spin, but that the sun circled the earth instead and that the observed data supported this. I am going to tweak the climatologist sim to see if I can make him do it again.
UAH satellite record for the poles shows warming trend of 0.44C, a much higher trend than for anywhere else. The anomalies, of course, are generally significantly greater than for the globe.
According to a data set favoured here, the Arctic appears to be warmer than the globe, and warming faster than the globe. Does this not corroborate the GISS extrapolation?
http://vortex.nsstc.uah.edu/public/msu/t2lt/uahncdc.lt
Tilo: Liked the article. The most effective argument I’ve seen against what you’re arguing is the animation of the loss of “multi-year” ice at the poles. Do you have any comment on those observations? Are they similarly extrapolated or measured directly. Your argument against extrapolation of rising land temperature to the ice cap seems to require that surface temperature over the ice cap remain somewhat constant. But, the depth maps they are presenting argue for warming. Obviously , I suspect their technique given their desire to present the case for warming.
barry:
“Does this not corroborate the GISS extrapolations.”
No, barry, the artic sea ice shore effect that GISS shows is a much larger variation than any actual warming trend at the poles.
JDN:
“Your argument against extrapolation of rising land temperature to the ice cap seems to require that surface temperature over the ice cap remain somewhat constant.”
JDN, in the article I give you a link to the SST dataset that GISS uses. You can have it give you anomaly charts for any month of any year. Try it and you will see that the SST’s are not warming nearly as much as the surface station. The water temperature has gotten slightly warmer up there, but the shore ice effect is making the shore stations much warmer. Look at the stations that I provide a link for and look at the variation. The Arctic SSTs don’t show anything like that much variation.
Have you ever seen where GISS and others overly report cooling? Not just half the time but ever? Non-randomness in errors strongly implies manipulation, if not pure agenda.
JER0ME (16:15:30) :”That is surely the basis for the very strong argument that a lack of polar sea ice is a negative ‘warming’ feedback as more heat is lost when there is no ice.”
I think your conclusion is right, but not for the reason you cite. The emittance of seawater is 0.993, close to a perfect black body. During the local polar winter, seawater will rapidly freeze. Ice slows the heat loss by both its insulating properties and its low emittance.
Summer conditions are different, of course. Remember, however, that the albedo of seawater is still fairly high at the zenith angles typical of the poles, depending on wind/wave conditions, plankton, time of day, etc. Open water polar albedos of .80 are typical, but not the maximum that can be encountered and often overlap ice albedo.
It is hard to make data where none exists. Oh, wait. Yes, it is. Never mind.