By Steve Goddard and Anthony Watts
Some of the excellent readers of the last piece we posted on WUWT gave me an idea, which we are following up on here. The exercise here is to compare GISS and satellite data (UAH and RSS) since the start of 2003, and then propose one possible source of divergence between the GISS and satellite data. The reason that the start of 2003 was chosen, is because satellite data shows a rapid decline in temperatures starting then, and GISS data does not. The only exception to the downward trend was an El Nino at the start of 2007, which caused a short but steep spike. Remembering back a couple of years, Dr. Hansen had in fact suggested that El Nino might turn into a “Super El Nino” which would cause 2007 to be the “hottest year ever.”
The last six years (2003-2008) show a steep temperature drop in the satellite record, which is not present in the GISS data. Prior to 2003, the three trends were all close enough to be considered reasonably consistent, but over the last six years is when a large divergence has become very apparent both visually and mathematically.
Since the beginning of 2003, RSS has been dropping at 3.60C/century, UAH has been dropping at 2.84C/century, and GISS has been dropping at 0.96C/century. All calculations are done in a Google Spreadsheet here:
The divergence between GISS and RSS is shown below. Since the start of 2003, GISS has been diverging from RSS at 2.64C/century, and GISS has been diverging from UAH at 1.87C/century. RSS has been diverging from UAH at minus 0.76C/century, indicating that RSS temperatures have been falling a little faster than UAH over the last six years, as can also be seen in the graph above.
Below is a 250km map of GISS trends from 2003-2008. One thing which stands out is that GISS has large areas with sparse or no coverage. Notably in Africa, Antarctica, Greenland, Canada, Brazil, and a few other places.
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Many of the GISS holes seem to be in blue regions on the map. Here is a post and video of the GHCN station loss over the past several years globally, created by WUWT contributor John Goetz:
Here are two images showing the difference between GISS global coverage in 1978 and 2008:
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There is a tremendous amount of station dropout in 30 years. Dropout is worst in the high northern latitudes, most all of Canada, and about half of Africa. Of particular note is the red band at the southernmost latitude, which “seems” to indicate a continuous coverage there. Of course we know that is not true, given the paucity of stations in the Antarctic interior. Read more here.
By contrast, while it doesn’t hit both poles (neither does GISS) UAH has much broader global coverage as seen below. Could this be part of the explanation for the divergence between GISS and satellite data? What do the readers think?
![[Image]](https://i0.wp.com/discover.itsc.uah.edu/amsutemps/browse/AMSU_A_15.latest.a_04.png?resize=520%2C278&quality=75)
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![[Image]](https://i0.wp.com/discover.itsc.uah.edu/amsutemps/browse/AMSU_A_15.latest.d_04.png?quality=75)
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How different would the GISS graph appear, if it showed a -3.6C/century cooling trend over the last six years? For reference, the steep GISS warming trend from 1980 to 2002 was about 0.4 degrees.
tty (16:24:03) :
A ten minute search on the web will locate up-to-date (and historical) data for a lot of those missing stations from the websites of the meteorological agencies of e. g. Canada, Sweden, Norway, Denmark, Australia etc. etc.
Ok… so can we just collect all the Rest of World data, unhansenized, and create our own Global Temperature Dataset (probably minus US unless NOAA data directly available)?
Is it possible to get the ‘more or less raw’ data needed to remove the Hansen bias from a dataset at least as representative as GISS (which seems not that representative… so the hurdle looks low…)
Basically, can we make one of those world maps, like above, that shows the coverage area of the available non-hansen datasets? And if that coverage area is ‘large enough’ assemble those bits into a cleaner data set? (And then use that dataset to measure the ‘quality’ of others…)
At least it would let us put Canada back in!
Tom in Texas: You wrote, “Why isn’t the data from ARGO being used?”
From December 1981 to present, GISS has used what they term Reynolds-Rayner-Smith SST data. The NCDC further identifies the version of data used by GISS as the Optimally Interpolated SST (OI.v2) in their detailed description of the GISTEMP data set here:
http://www.cdc.noaa.gov/cdc/data.gistemp.html (In the above comment, I wrote 1980. It’s 1981.) The OI data uses satellite, ship and buoy data, though I don’t believe they’re the same buoys as ARGO. More on the OI SST data here:
ftp://podaac.jpl.nasa.gov/pub/sea_surface_temperature/reynolds/oisst/doc/oisst.html
jae (19:19:33)
6) Computer programs, although written in Fortran, almost unintelligible, and not subject to any known QA/QC programs, have been posted on the Internet for your perusal.
Where? (I was pretty good with FORTRAN once. it was my first computer language.)
I’d love to get a look at the guts for a little QA exercise. (Though if nausea is induced I’m bailing… 8-0
Surprise! A cycle 23 sunspot is “trying to form” just near the solar equator… 23 ain’t givin up just yet! http://www.solarcycle24.com
crosspatch (20:28:35) :
“Or we can just measure the ocean temperature. That is pretty much where the vast majority of the Earth’s heat is stored. I would measure it on the sea floor, though, not on the surface.”
Ha, ha! Oceans have a rather large range in bottom depth. Let’s say from 150 meters at the continental shelf break to 11,000m in the Mariana Trench. So what is your datum of reference?
Besides, below certain great depths the water temperature is stable at a minimum temperature that corresponds with the pressure and the salinity of the water and is thus not influenced by changes in the ocean’s heat content. Measuring temperatures there wouldn’t mean anything in relation to climate change, be it cooling or warming.
To Alan and others: similar “pauses” in the warming have been observed before: take the 79-85, the 86-95, the 90-96 periods and all you’ll get is an apparent cooling. Nevertheless, no-one in his (her) right mind would dare to say that temperatures decreased since 79, 96 or 90.
This is short-term variability opposed to long-term trends. By the way, take a look at the UAH tropospheric temperature data for January http://discover.itsc.uah.edu/amsutemps/amsutemps.html You can check that the temperatures we have rightnow are in no way “cooler” than what we had the previous years. Despite la nina. And the solar minimum.
Alan Wilkinson (23:41:57) :
just where has the additional heat from CO2 forcing gone?
Silly suggestion, but why could this extra heat not have gone into outer space? It seems logical to suggest that if heat [from the sun] can come in, the it should be able to escape also.
Joel (18:09:28)
Sure, sure, trend length can be argued in circles forever. Look at it this way. Temperature seems to have some of the behaviour of a cycle and 2003 looks like a peak. As the temperature curve’s negative slope steepens you’ll see why attention to inflection points can give understanding about a trend in a manner that arguing about its length won’t.
Another point I’ve made before with reference to the common use of 30 years as standard length of time to determine a trend. Well if the PDO has a phase length of 30 years, then looking at the last 30 years will always give you the wrong prediction for the next 30, if the PDO is as determinative of climate as I believe it is. Nice, huh?
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off topic, but is this an equatorial sunspot?
http://sohowww.nascom.nasa.gov/data/realtime/mdi_igr/1024/latest.html
if so, would it be safe to assume that this is a SC23 spot? it shows up on the magnetogram, but i’m not well versed in how to interpret the polarity depicted in the magnetogram.
The GISS minus RSS linear trend does not show any seasonal pattern, so I see no reason to believe it is related to “melting of ice” or any other summer phenomenon. UIUC shows global sea ice right at the 30 year mean. Regardless, why is the divergence occurring? A discrepancy of one month might be overlooked, but 72 consecutive months?
The reason for land only maps was to highlight the missing areas on land. That is the default setup on their site, but you can generate GISS ocean maps as well from the link in the article.
On preferring Hadcrut to GISS on the basis of coverage: of the 2592 gridcells in Hadcrut about 11% have no data at all, for any year; 27% have data for 10% of the time or less. Mysteriously, Cruabs, the dataset containing the data for the baseline averages that are subtracted to give anomalies, has values for every gridcell. Not what I’d be looking for to take a planet’s temperature.
That said, I’m interested that a visual “wiggle match” of satellite and ground-based temperature measurement shows pretty good agreement which, to me, suggests that all this temperature data isn’t just pure fantasy.
To Alan and others: similar “pauses” in the warming have been observed before: take the 79-85, the 86-95, the 90-96 periods and all you’ll get is an apparent cooling. Nevertheless, no-one in his (her) right mind would dare to say that temperatures decreased since 79, 96 or 90.
There was a plausible explanation for the pauses you mention, i.e. El Chichon in 1982, Pinatubo in 1991 and ENSO. Between 2003-2007 there were no volcanos and the PDO/ONI indices generally favoured warming. Remember ‘lack of volcanos’ is one of the reasons (perhaps now the only reason) given for the early 20th century warming.
I don’t get it. Climate scientists are supposed to have enough knowledge about the climate system that they can confidently attribute late 20th century to anthropogenic influences. But when the climate doesn’t respond as expeted – it’s just natural variability. Now fair enough I can understand that they can’t predict volcanos and probably not ENSO events either but when both these factors are weighted in favour of warming – what other ‘natural variability’ has caused a 5+ year lull.
Hadcrut3 is out now. Huge drop in December to 0.307C (from a revised November number of 0.400C). 2008 average of 0.325C – the lowest since 2000.
It looks like all the monthly data has been adjusted back to August 2007 so will have to be re-entered for those keeping track.
In most scientific and engineering endeavours, the people in charge of the data respond to discrepancies like this with concern and thoughtful analysis.
There must be an explanation for the GISS/satellite divergence over the last 72 months, and it would be very helpful to policymakers (who rely heavily on the GISS graphs) to be informed about the explanation.
If you follow the link to woodfortrees and use 1979 instead of 2003, you will notice that the GISS data is usually higher and only converged for high points like 1998.
I hope this gets through. 😉
The Treasure Island / I Don’t Know What The Temperature Is Story
Captain Andrew is a sea captain in Seatown. Drinking one night at a bar, he hears there is treasure on Treasure Island. He vows he must have this treasure and goes to the mapmaker, Mr. Burnes, to buy a map with Treasure Island on it.
Mr. Burnes (with a pleasant smile): “Our maps are $50”
Captain Andrew: “Arrrrr!” He buys the map (with a scowl) and sets sail.
After months on the open sea, braving many storms and starvation and bouts of scurvy he gets to where the map says Treasure Island is, coordinates (x,y).
No island. He sails around the area looking for it, but can’t find it. He realizes he is running out of water and has to sail home, giving up the search.
When he gets back to Seatown he angrily goes back to Mr. Burnes, demanding an explantion of why he didn’t find Treasure Island.
Mr Burnes: “Yeah, about that… while you were gone we found out our map was inaccurate. We have since produced a better one. It’s $100 (inflation)”
Captain Andrew: “Arrrr!” He buys the map (with a more intense scowl) and sets sail.
After months on the open sea, braving many storms and starvation and bouts of scurvy he gets to where the map says Treasure Island is, coordinates now (x,y+50).
No island. He sails around the area looking for it, but can’t find it. He realizes he is running out of water and has to sail home giving up the search.
When he gets back to Seatown he angrily goes back to Mr. Burnes, demanding an explantion of why he didn’t find Treasure Island this time.
Mr Burnes (with pleasant smile): “Yeah, about that… while you were gone we found out our map was inaccurate. We have since produced a better one. It’s $150 (inflation again)”
Captain Andrew: “Arrrrr!” He buys the map (with an even bigger scowl) and sets sail.
After months on the open sea, braving many storms and starvation and bouts of scurvy he gets to where the map says Treasure Island is, coordinates now (x+10,y+75).
No island. He sails around the area looking for it, but can’t find it. He realizes he is running out of water and has to sail home giving up the search.
Captain Andrew is mad as h*ll.
On his way, he sees a shell of a man in the ocean, who is clinging to a plank.
Captain Andrew rescues the man, gives him some water, but still angry from his failures he screams at the rescued man:
“By my beard, you scurvy spider! …Where in blazes is Treasure Island?!”
Shell of a Man: “It’s around here somewhere. Let’s look at your map.”
They look at the map together. When he sees the map is made by Mr. Burnes he says:
“Oh… don’t buy maps from Mr. Burnes. His maps keep changing. You can’t trust him”
Captain Andrew: “Arrrr!”
THE END
What’s going on with the AMSU temperature http://discover.itsc.uah.edu/amsutemps/execute.csh?amsutemps ? Since Jan 08 it has been going up at a rate of approximately 0.1 def F per day.
E.M.Smith (01:12:47) :
There are several references to GISS’ ModelE at http://wattsupwiththat.com/2009/01/06/ncdc-updates-database-for-dec08-ncdcs-own-graphic-shows-10-year-cooling-trend/
The source is viewable at http://www.giss.nasa.gov/tools/modelE/
To find that blog entry I Googled “modele werme fortran” and Google include “model” as a search term. That pulled up some ancient history, fortunately not all mine. 🙂 Leif might enjoy it.
Bring barf bags, though I did defend ModelE a little bit. (I.e. it was written by scientists, not software engineers.)
Just to clarify the point of the article again, we are not discussing or speculating what the long term temperature trend is. The topic is that GISS and satellite data are diverging linearly over the last 72 months.
“The planet is not anthropologically unstable. The people are.”
– Rich Gele’
Welcome to the new millenium folks.
Rich,
Interesting information. Then you can say almost 40% of Hadcrut gridcells have data 10% of the time or less. Seems to me that this is not something that can be overcome by statistical manipulation. How can HAdcrut publish any data with any confidence?
Pearland,
Maybe. The orientation is a little odd on that one, however, if it does become a sunspot, it most likely is a Cycle 23. In the southern hemi white-black is a Cycle 23. Not unusual I think for a few previous cycle spots to occur long after the next cycle starts (whenever that was – Jan 08?)
Paul said;
“Silly suggestion, but why could this extra heat not have gone into outer space? It seems logical to suggest that if heat [from the sun] can come in, the it should be able to escape also.”
I appreciate that the theory of AGW is in effect based on heat being unable to escape the thick ‘girdle’ of co2 back into space, but in reality how much of the heat that comes in plus the heat we create, disappears into space and over what period?
TonyB