There is some interesting news in the October RSS global temperature anomaly numbers. We are still cooler than one year ago, and the 12 month trend continues to drop. But, the big news is that RSS has revised their dataset to reflect improvements in quality control.
Version 3.1 of the TLT Lower Troposphere data has been replaced with version 3.2 You can view both datasets:
Version 3.1 here
Version 3.2 here
Here is a graph showing the two dataset plotted simultaneously. No October data exists for Version 3.1 For the most part, it looks like Version 3.2 has warmed a bit more in the past for the 1979-1990 period, slightly reducing the overall trend:
Click for a much larger image
Here is what RSS says about this change
Version 3.2 simplifies and improves a number of processing steps. The changes are:
- Target Factors and Scene Temperature Factors are determined entirely during the merging process using monthly gridded data. In V3.0 and V3.1, the target factors were determined offline using monthly global averages, and then applied to the monthly gridded data. The new methods streamline the data processing, and result in very small changes in long-term trends.
- A more comprehensive analysis of the intersatellite differences has been performed. As a result of this study, we have identified several satellite-months of data that appear to be inconsistent with measurements from other satellites during the same time period. These typically occur near the beginning or end of a satellite’s life. These data have been removed from processing.
- We reduced the systematic bias that occurs due to spatial-derivative effects in the TLT extrapolation process that can be large at high latitudes. The effects of this bias are particularly large near Antarctica. (see Section 2c in the preprint for a discussion)
- Quality control for individual TLT measurements has been improved, which results in less radio frequency interference (RFI). RFI induced artifacts were previously visible in our TLT monthly maps, particularly near Ascension Island in the tropical Atlantic Ocean.
For more details:
| Changes from RSS TLT Version 3.1 to Version 3.2 | |
| Changes from RSS Version 3.0 to RSS Version 3.2 |
The changes listed above result in a slight change in the decadal trend, from 0.183°C/decade to 0.180°C/decade. A difference of a mere 0.03°C
Update 11/09: The graph above is from RSS PDF Changes from RSS TLT Version 3.1 to Version 3.2 and represents data from 70.0S to 82.5N. In comments it’s been pointed out that the current RSS 3.2 raw TLT data for the same latitude span shows a .157C/decade trend and elsewhere on RSS own website they show a .158C/decade trend for the same data. We hope to get an answer from RSS on Monday to help resolve this discrepancy.
As for the monthly data for October:
The RSS (Remote Sensing Systems of Santa Rosa, CA) Microwave Sounder Unit (MSU) lower troposphere global temperature anomaly data for October 2008 was published Friday and has remained essentially unchanged, even with the new data version, from September with a value of 0.241°C (V3.1) for a change (∆T) of -0.06°C
RSS
2008 1 -0.070
2008 2 -0.002
2008 3 0.079
2008 4 0.080
2008 5 -0.083
2008 6 0.035
2008 7 0.147
2008 8 0.146
2008 9 0.241 (V3.1)
2008 10 0.181 (V3.2)
The October 2008 number is 0.181°C
Click for a larger image
The RSS data is here (RSS Data Version 3.2)
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They working very, very hard to find a linear trend in that data.
If the temperatures are cyclical, why try to force-fit a single, simple, linear slope to sinusoid data?
Then again, maybe they don’t get paid as much for a cyclical curve ……
I was wondering where the RSS data was. Thanks for the heads up.
I see hardly any difference. The Ver3.2 minus 3.1 is basically a flat line.
Last Autumn was fairly warm for the NH. The following Winter NH temp plunged, and that drop was only amplified by the preceeding warming. Overall, global temps have been following ENSO/PDO trends, and if the current neutral ENSO trend shifts negative, 2009 could produce a cool/dry climate for much of the NH.
I don’t get excited by seasonal trends, but there has been a definite cooling these last 6 seasons. If I was an AGW Alarmists I would be a bit alarmed.
Isn’t it funny when temps don’t go the want thy want they want to change the way temps are recorded.Also on noticed on your sea ice chart we are NOW ahead of all the past 7 years. I wonder if this will make the news as last year did with supposted low ice??
I’m not sure why you measured dT between September and October using 3.1 for September, and 3.2 for October. I realize there is no October for 3.1, but that doesn’t justify comparing the October number from 3.2 to the the September number from 3.1.
I don’t see how this really impacts anything. Both series show pretty much the same thing.
REPLY: I realized that might look odd. It is because I have a bunch of posts each month that used 3.1, and I’m really time rich enough for going back to revise each one.
What I posted last month was 3.1, and in each of these monthly posts, I compare the previous month’s data. Next month will be 3.2 against 3.2. I was going for consistency in the way I do the posts, I can’t help it if the researchers change the data.
Or I could simply make no comparison at all.
-Anthony
Southern Hemisphere has another negative temperature anomaly, which makes 7 out of 10 months negative so far this year.
I wonder how the 2007 numbers look along side the 08 ones. It might be an interesting comparison to me it looks like we are headed for cooler times.
Bill Derryberry
Al Gore has written: The Climate for Change
New York Times, November 9, 2008
Following is the comment I submitted in response:
My first reaction was that they are being upfront in explaining what they have done. Which then suggests to me good things like objectivity and technical discipline.
If all temperature gurus could do the same perhaps there wouldn’t be so much contention over temperature constructions.
David, problem is: Methanol is Poisonous. You think they raised a stink over 1.5% MTBE, just wait and see what they do over Methanol. Besides, I think something’s wrong with that number. The Plant is incredibly expensive. About 10 times more expensive per gallon than ethanol, and the process is very labor-intensive – maybe as much as 20, or 30 times.
Hey, I’m in favor of whatever pays in the free market. I think all subsidies and undue burdens should be lifted and let the market decide. I don’t think the government should be in the oil biz. Or the anti-oil biz.
The two versions do look quite similar. But does this mean they are genuinely fining down their accuracy and that the end result is that much more robust?
And how does it all compare with UAH?
Bill in Vigo, according to UAH 12 mo running mean 2007 came in at .282 Right now, 2008 is looking like .04. If this hold, and it seems quite possible, we would be looking at a difference of about 0.24 degrees.
Does that sound about right?
not related to this topic…
Sunlight has more powerful influence on ocean circulation and climate than North American ice sheets
A study reported in today’s issue of Nature disputes a longstanding picture of how ice sheets influence ocean circulation during glacial periods.
Is there a problem with the value for Sept in the RSS plot shown above in red?
I was looking for 0.241 but it is not there. What is shown is slightly above the 0.181 for October.
Not trying to be a pedant but the table and the graph seem to be at odds?
Now it could be that this has been raised in comments above but I will not be going through these right now. If so my apologies.
And I forgot to add “thanks for the post Anthony” – more haste less speed!!!!
Thanks for the work you did on this, especially in the comparison between the two versions. I was just going to run a check myself with Excel {I’m a bit rusty and need the practice}. It looks like the difference you’ve shown confirms what eyeballing the first graph suggests — that most differences of note occur prior to 2003. Perhaps the analysts are becoming more sophisticated in processing the data.
The data for the next five years should show whether this past year was just a quick blip or the start of a downward trend from the temperature plateau of the past few years.
Kum Dollison (22:00:35) :
David, problem is: Methanol is Poisonous. You think they raised a stink over 1.5% MTBE, just wait and see what they do over Methanol. …
Ethanol is poisonous, too, and probably kills more of us than methanol does (especially at frat parties). Up here in Illinois, we’ve had 10% ethanol gas available for a good number of years. It ran about 10 cents a gallon cheaper than real gasoline, and I’m estimating I got about 8-10% worse mileage from it compared with the good stuff.
We used to buy cans of ‘Heet’ methanol to prevent gas-line freeze in the winter. Now, thanks to huge government ethanol subsidies, I can save the 60 cents every other tankful that I used to pay.
Where would we be without our government, eh?
The heat is on in Georgia, Tennessee and Alabama.
Temperatures in six Southeastern cities, including Chattanooga; Atlanta; Athens, Ga.; Augusta, Ga.; Huntsville, Ala.; and Birmingham, Ala., ranked in the top 50 of cities across the country showing above-normal average temperatures.
“The climate has been warming. It’s pretty unprecedented,” said Stephen Konarik, a meteorologist with the National Weather Service in Peachtree City, Ga.
The trick here is these comedians are using 2007 data. They must have seen the 2008 summer numbers and decided it was time to throw up a smoke screen.
http://www.istockanalyst.com/article/viewiStockNews+articleid_2778499.html
“from 0.183°C/decade to 0.180°C/decade. A difference of a mere 0.03°C”
Shouldn’t that be “a mere 0.003…”?
The September 2008 number seems to be wrong – shouldn’t it be 0.194
Oops – sorry should have been 0.211 for v3.1 with a reduction of 0.017 for v3.2
Thanks for flagging this, Anthony. I’ve updated WFT to use the new 3.2 dataset and hence it is now up to date:
http://www.woodfortrees.org/plot/wti/last:12/plot/hadcrut3vgl/last:12/offset:-0.15/plot/gistemp/last:12/offset:-0.24/plot/uah/last:12/plot/rss/last:12
You wrote “a slight change in the decadal cooling trend, from 0.183°C/decade to 0.180°C/decade”. I think you meant warming, but in any case my OLS makes it 0.157°C/decade:
Graph: http://www.woodfortrees.org/plot/rss/plot/rss/trend
Raw data: http://www.woodfortrees.org/data/rss/plot/rss/trend
I’d just like to check we’re using the same dataset and the same algorithm, because I’m worried one of us may have it wrong (and it could well be me!)
REPLY: Thanks for catching that I think I wrote originally slight cooling to the decadal trend, but somehow it got jumbled in some of the edits. This article isn’t my best writing because I had started to write it based on just comparing month to month, then discovered that the data didn’t match previous months. So lots of editing an cut/paste ensured. Fixed. – Anthony
I dunno, the RSS changes described seem above board and proactive to me as well as inconsequential re: long-term trends. Wish that were common practice, frankly.