Category Archives: GISTEMP Replication

GISS Gridded and Zonal Data

Last week, I wanted to determine what GISS’ tropical land-and-ocean time series was. This did not prove as easy as it sounds. Nothing in GISS is intrinsically complicated – it;s all just averaging and smoothing and adjusting. But the code is written as though the whole thing were being done on a Commodore 64 with […]

Hansen's Digits

Both Luboš and David Stockwell have drawn attention today to the distribution of digits in Hansen’s GISS, suggesting that the distribution is, to borrow an expression, a fingerprint of anthropogenic impact on the calculations. I disagree with both Luboš and David and don’t see anything remarkable in the distribution of digits. I don’t disagree with […]

A Collation Utility for GISS dset1 and dset2

GISS has been providing a considerable amount of intermediate information on their results. Unfortunately, it’s been provided in binary format that is presumably suited for people who speak Fortran with a Unix accent. I presume that such people converse with one another in medieval Latin. It’s not very handy for people who use modern languages. […]

Hansen’s “Reference Method” in a Statistical Context

I’ve discussed “mixed effects” methods from time to time in paleoclimate contexts, observing that this statistical method known off the Island can provide a context for some paleoclimate recipes, e.g. in making tree ring chronologies. This would make a pretty good article. Another interesting example of this technique, which would also make a pretty good […]

GISS Gridded Data

GISS gridded data is online but in a format that is unintelligible to people who are working with modern computer languages, as opposed to Fortran and who do not know whether their machines are “littleendian” or “bigendian” (see here for GISS discussion) – phrases rather reminiscent of Gulliver’s Travels, perhaps an apt text for Hansen. […]

NASA Step 2 Some Benchmarks

I’m finally stating to come up for air after dealing with the fetid grubs and maggots of Hansen’s code. Needless to say, key steps are not mentioned in the underlying publications, Hansen et al 1999, 2001. I’m not going to discuss these issues today. Instead, I want to show 3 case studies where I’ve been […]

NASA Step 2: Another Iteration

Here are some more notes and scripts in which I’ve made considerable progress on GISS Step 2. As noted on many occasions, the code is a demented mess – you’d never know that NASA actually has software policies (e.g. here or here . I guess that Hansen and associates regard themselves as being above the […]

GISS Step 2

Here are some notes and functions on some work that I did last fall trying to benchmark the GISS Step 2 adjustment in a non-US site. My first efforts to follow the written prescription have been unsuccessful. I’m placing some tools and a benchmark case (Wellington NZ) online and perhaps people who are trying to […]

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, […]