In the “good old days” (August 25, 2007: after they had corrected their Y2K error), I downloaded Hansen’s “combined” version (his dset=1).
Jerry Brennan observed today that Hansen appeared to have already “moved on”, noticing apparent changes in Detroit Lakes and a couple of other sites. Here is a comparison of the Detroit Lakes (combined) as downloaded today, compared to the version downloaded less than 3 weeks ago. As you see, Detroit Lakes became about 0.5 deg C colder in the first part of the 20th century, as compared to the data from a couple of weeks ago.
In a few more weeks, maybe Hansen will have 1998 – and perhaps even 2006 – on top again.
Despite these large changes, Hansen, as with the Y2K corrections, did not provide any notice to readers that major changes (not arising through ordinary operations) had been inserted in his records.
It looks like this is the reason for the conundrum observed in my last post . I never thought of checking to see if Hansen had altered early 20th century values for Detroit Lakes MN between August 25 and Sept 10. It’s hard to keep with NASA adjusters. As noted previously, no wonder Hansen can’t joust with jesters, when he’s so busy adjusting his adjustments.
Here is the same comparison for Boulder CO, another site mentioned by Jerry, showing major changes in Boulder temperature estimates for the 1980s!
As a result of revisions made within the last 2 weeks, NASA now believes that the temperature increase in Boulder since the 1980s is about 0.5 deg more than they believed only a couple of weeks ago. Boulder is the home of IPCC Working Group 1, the site of UCAR’s world headquarters, NCAR’s site and home to hundreds, if not thousands of climate scientists. You’d think that they’d have known the temperature in Boulder in the early 1980s to within 0.5 degree. I guess not.