Check out Petaluma CA at Anthony Watts’ blog.
Anthony has shown the GISS unadjusted temperature graphic. In this case, the GISS raw data appears to be mostly the same as USHCN adjusted (filnet) up to different rounding; a few isolated values available in USHCN are missing in GISS raw for some strange reason. I’m starting to keep track of the GISS raw source, as I pick up these files. I’m going to check whether the USHCN filnet is consistently picked up or not. At any rate, it is here.
The GHCN raw version is the same as USHCN raw version and differs from the GISS raw version. The GHCN adjustment has the effect of lowering early 20th century temperatures relative to modern temperatures. The GISS adjustment goes the opposite direction from the GHCN adjustment. Two figures are shown below. First the raw USHCN minus the three adjusted versions: USHCN, GHCN and GISS and then the amount of the GISS adjustment relative to the GHCN adjustment, which reaches up to 1.5 deg earlier in the century.
In the cases that I’ve examined, Parker uses GSN data (which appears to be equivalent to GHCN raw data where they overlap.) In this case, Hansen adjusts for 1.5 deg of urban warming that Parker has demonstrated not to exist. If Parker is right then the GISS data is seriously understating 20th century warming by adjusting for a supposed urbanization trend effect that Parker has “demonstrated” is not present in the data.
Here are the 7 versions overlaid:
The station history at CDIAC is not up to date http://cdiac.ornl.gov/ftp/ushcn_monthly/station_history showing moves with directions are shown in 1927, 1941, 1954, 1968, 1969, 1981 and 1991, but not two recent moves listed at MI3. Obstructions at the present site are listed at MI3 as: “MMTS 259/35 F&P 055/10 TREES 001-030/30-45/15-3 TREES 150-210/320-180/3-5 TREES 240-330-359/40-30-25/12-13-15 BLDG 280-330/45-55/6-6ll”. Go to Anthony’s pictures for more details on the obstructions described on the form so laconically.