## Category Archives: GISTEMP

### Homogeneity Adjustment – Part II

Yesterday I described the work done to the surface station records in Hansen Step 2 in preparation for adjusting urban stations to match the trend of nearby rural stations. The basic substeps are Deciding which stations are rural and which are urban. The methodology used for most of North America differs from that applied to […]

### Homogeneity Adjustment – Part I

My curiosity in the mathematics behind the homogeneity adjustment caused me to finally take a close look at Hansen Step 2. This turned out to be an incredibly torturous task. A quote from a Stephen King short story, The Jaunt, came to mind as I plowed through lines of code: “It’s eternity in there…“. However, […]

### NASA Follows CA Recommendation

On Feb 20, 2008, I wrote a post reviewing the provenance of various versions of an individual USHCN station (Lampasas), observing that a much more recent version was available at NOAA than at CDIAC) (the source used by NASA. I made the following recommendation: Regardless of whether these station histories “matter”, surely there’s no harm […]

We have talked about finding Waldo for a while. Here are a few interesting graphics showing the Adjusters in Peru. Here are 4 stations where temperatures in the mid-20th century have been lowered by around 3 deg C. These are all reverse UHI effects. For all of the above graphics, I’ve plotted original monthly data […]

### Hansen Step 2 – First Thoughts

The source code for Hansen’s Step 2- the “urban adjustment” step is online. If anyone’s been able to operate the program through to Step 2, I’d be interested in some stage results for the stations discussed here. The verbal description is not clear and the code is a blizzard of old-fashioned Fortran subscripts, so it […]

### Hansen Step 1

Hansen “Step 1″ which was the source of the August crossword puzzles does not occur in a crossword puzzle form in the USHCN stations that we’ve been discussing this week. The “Hansen bias” in combining scribal versions, noticed by John Goetz, does not occur in USHCN stations for two separate reasons: (1) in the USHCN […]

### Should NASA climate accountants adhere to GAAP?

Shortly after, NASA published their source code on Sept 7, we started noticing puzzling discrepancies in the new data set. On Sep 12, 2007, I inquired about the changes to Hansen and Ruedy, observing that there was no notice of the apparent changes at their website: Dear Sirs, I notice that you’ve changed the historical […]

### The September 2007 Bear Market in NASA Temperature "Pasts"

Since August 1, 2007, NASA has had 3 substantially different online versions of their 1221 USHCN stations (1221 in total.) The third and most recent version was slipped in without any announcement or notice in the last few days – subsequent to their code being placed online on Sept 7, 2007. (I can vouch for […]

### The Bias Method's Perfect Siberian Storm

I have been spending some time (my wife would say “too much time”) examining how the Hansen Bias Method influences the temperature record. We have already observed that the Hansen method introduces an error in cases where the different versions are merely scribal variations. See http://www.climateaudit.org/?p=2019 and discussion. The cause of the error has also […]

### Hansen's Station Lists

The section of Hansen’s code that we’d been looking at immediately prior to the dump of relatively unannotated code was how Hansen combined scribal versions of different stations in a 2-column case – which looks to contain a material error already discussed without the benefit of source code and which is going to be examined […]