On January 16, 2008, I posted a note on Hansen et al 1988 containing the following graphic comparing the three Hansen scenarios to the most recent GISS and RSS temperature versions.
Although there had been much furore in the past about the differences between Hansen Scenarios A and B in previous controversy, I observed that Scenarios A and B were both at very elevated levels by 2010 and that noticeable increases in RSS temperature would be required to keep pace even with Hansen Scenario B. While I expressed this in terms of the RSS data, the same thing is true for the GISS surface data.
This graphic used the following file downloaded from RSS on January 16, 2008
Eli Rabett today accused me of using “an older version” of the RSS temperature reconstruction as follows:
But lo, our auditors had also used an older version of the RSS microwave tropospheric temperature reconstruction. It had a serious error. What does the corrected version look like?
An older version?
Two days after my post, on January 18, 2008, RSS issued an amended version of their TLT data http://www.remss.com/pub/msu/monthly_time_series/RSS_Monthly_MSU_AMSU_Channel_TLT_Anomalies_Land_and_Ocean_v03_1.txt
Unfortunately, there is no announcement of the error at the RSS homepage http://www.remss.com/msu/msu_data_description.html. As far as I know at present, the only notice of the error is through a readme (http://www.remss.com/pub/msu/data/readme_jan_2008.txt ) dated January 16, 2008, but only posted up on January 18, 2008 (see http://www.remss.com/pub/msu/data/ ) . Rabett did not state how he happened to become aware of the readme mentioning the error as to my knowledge, it is not linked through the home page or through an explicit announcement. Rabett linked to the readme, carefully including the reported date of January 16, 2008, but failing to mention that the readme was posted on Janueary 18, 2008 (also after my post).
Last January, I made a small change in the way TLT is calculated that reduced the absolute
Temperatures by 0.1K. But I only used the new method for 2007 (the error).
When the data are merged with MSU, MSU and AMSU are forced to be as close as possible to each
other over the 1999-2004 period of overlap. This caused the error to show up as a downward
jump in JAnuary 2007. To fix the problem, I reprocessed the 1998-2006 AMSU data using the new
code (like I should have done in the first place), and merged it with the MSU data.
We would like to thank John Christy and Roy Spencer, who were very helpful during the diagnosis
Carl Mears, RSS, January 16 2008
Thus, on January 16, 2008 when I did my post, I was using the current RSS version. Yes, two days later, RSS changed their 2007 numbers. Here are two graphics showing the impact of the RSS changes – Jan 3, 2008 (red) and Jan 18, 2008 (blue):
and a second one showing the difference between the two series, which works out to about 0.12-0.14 deg C during 2007.
Also here is a revised version of my graphic, implementing the Jan 18, 2008 RSS changes. The main point of my earlier post clearly stands — in 2010, the difference between Scenarios A and B is not particularly large and some of the past furore over scenario versions becomes less material.
In his coverage of the RSS error, Rabett disparaged my analysis, implying that, by using an “older version” of the RSS data, I had done something improper. Rabett misleadingly failed to cite the dates of the RSS versions, which would have shown that I had used the then current RSS version (Jan 3, 2008, then current as at Jan 16, 2008) and that that the newer version (Jan 18, 2008) was not available at the time of my post. Rabett shows the readme dated January 16, 2008 implying that I should have been aware of it (even though it is nowhere linked on the RSS webpage) without stating that it was posted on January 18, 2008 subsequent to my post.
In the same post that Rabett criticized here, as originally written, I had incorrectly missed a comment in Hansen et al 1988 saying that Scenario B was the “most plausible”, an error which I picked up about 8 hours after the original posting (about 9 am EST) and immediately corrected it when I noticed it. So there was an actual incorrect statement at CA for about 8 hours. Imagine that. I didn’t post up notice of the change until about 9 hours later (I was playing in a squash tournament and had to do some chores and went out after making the correction and posted the notice when I returned.) Meanwhile, a few hours after I made the correction, Lambert wrote a post on this error without mentioning that the error had already been corrected as at the time of his post. This caused a tizzy of excitement over at Deltoid over the possibility that I might actually have made a mistake on something (outside my core area). Gavin Schmidt interrupted his day at NASA to weigh on the matter at Deltoid.
I don’t claim to be infallible. I corrected this particular error promptly. Compare the treatment of an error in an incidental blog post that I corrected within about 8 hours to the treatment of the RSS error. Do Rabett or Lambert excoriate RSS for their goof? A goof that occurred in a high-profile data set? Of course not. To the extent that they place any blame, Rabett blames me for not using an RSS version that didn’t even exist at the time of the post.
As to RSS, they made a mistake and corrected it. Good for them. Errors happen and RSS corrected their error. Rabett observed of the RSS error:
PPS: Lots of folk are falling into the RSS error trap.
Rabett proceeds to blame users of RSS data. The fact that users are “falling into the RSS error trap” is one more good reason why RSS should have issued a clear error notice, rather than the obscure readme. They should issue a proper notice of the error in their public webpages and wherever else appropriate. They were pretty quick to publicize errors by Spencer and Christy and should accord equal publicity to their own error.
Update Jan 24, 2008 12.40 pm:
Here is a version showing including the MSU version centered to synchronize with GISS for the period up to 1987. As you can see, the MSU version was bracketed by the GISS and old RSS versions. These spaghetti graphcs get pretty messy pretty fast and since it was bracketed, I did not include it in my prior version. Eli Rabett has made an issue of this and I have accordingly shown the MSU version here on the same basis as the prior graphic. As you see, it is no longer bracketed by GISS and the new RSS version, but is slightly lower than either, the point of my post remaining unaffected.
Update: Jan 27, 2008
John Christy observed below that “one must either multiply the surface by 1.2 or divide the troposphere by 1.2″ to gave apples and apples. I will re-plot the graphic once I clarify a point on this.