People send me stuff. Today, alert reader Clay Ablitt sends this:
I have been keeping a record of a lot of the different data sets that are put out by RSS and UAH because i believe they are a more reliable data set than NASA or NOAA data.
I noticed in the latest monthly update that added the September data, the historic temperatures were adjusted without any notes or version change.
I have attached the data from August and the newly adjusted data from September for your consideration. This will have an impact on all RSS data sets that include the ocean temperatures such as the global RSS TLT data which has continued to show a pause since February 1997.
He also attached an Excel spreadsheet with two pages, one for each month, a link to which is available here: rss-temperature-trend-sep-oct-2016 (.xlxs)
I checked out the worksheet, and he appears to be correct. There is an unannounced change to the Remote Sensing Systems data. The last change note I am aware of is this one: http://www.remss.com/node/5166
There seem to be no other mentions on the remss.com website that explain this change as observed in the flip chart below:
(click image if it doesn’t animate for you while reading this)
I asked UAH scientist Dr. Roy Spencer about it today, showing him the data and he replied:
We suspected they have a revised LT in the works, after they came up with a new MT.
“MT” refers to Middle Troposphere data, and “LT” refers to Lower Troposphere data. Last March, WUWT covered their adjustment to the MT data, making the trend warmer.
Of course, the unannounced LT adjustment discovered by Ablitt also makes the trend warmer, some thing that isn’t entirely unexpected given the remarks last year by RSS chief scientist Carl Mears:
All that is about to change. Readers may recall a video produced by the execrable “Climate Crock of the Week” activist Peter Sinclair that we covered here where the basic premise was that the “satellites are lying“. It seems to me based on his recent comments that Dr. Mears has gotten fed up with people using his RSS data set to suggest that the world isn’t warming as he expects it should. From the video Mears states:
They just wanted to know, you know, they wanted to fine-tune their statement about, you know, whether , you know, the surface temperatures are more accurate or the satellite temperatures are more accurate, and initially they wanted to say something like “But you really shouldn’t trust the satellite temperatures, you should go with these surface temperatures”, and I said, “Well, what I would like to emphasize, you’d really want to look at all the different datasets, so you don’t want to trust only the satellite temperatures, you want to look at the surface temperatures, and – and that sort of thing.
On his website, Mears makes this statement:
Recently, a number of articles in the mainstream press have pointed out that there appears to have been little or no change in globally averaged temperature over the last two decades. Because of this, we are getting a lot of questions along the lines of “I saw this plot on a denialist web site. Is this really your data?” While some of these reports have “cherry-picked” their end points to make their evidence seem even stronger, there is not much doubt that the rate of warming since the late 1990’s is less than that predicted by most of the IPCC AR5 simulations of historical climate. This can be seen in the RSS data, as well as most other temperature datasets. For example, the figure below is a plot of the temperature anomaly (departure from normal) of the lower troposphere over the past 35 years from the RSS “Temperature Lower Troposphere” (TLT) dataset. For this plot we have averaged over almost the entire globe, from 80S to 80N, and used the entire TLT dataset, starting from 1979. (The denialists really like to fit trends starting in 1997, so that the huge 1997-98 ENSO event is at the start of their time series, resulting in a linear fit with the smallest possible slope.)
Mears uses the term “denialist” so there goes his objectivity when he feels the need to label people like that.