Willis Eschenbach received a message today that the CRU list of stations used is online at http://www.cru.uea.ac.uk/cru/data/landstations/ . The webpage says:
The file gives the locations and names of the 4138 stations used at some time (i.e. in the gridding that is used to produce CRUTEM3) during the period from 1851 to 2006. All these stations have adequate 30 year averages for 1961-90 as defined in Brohan et al. (2006). The 4138 total is lower than the 4349 value given as the starting point for Brohan et al. (2006) and used in the latest IPCC Report. A small number of stations have been removed during Brohan et al. (2006) because of the presence of duplicate data and insufficient coverage for the period 1961-90.
The numbers we use are listed in numerical order up to station number 988360. Up to this point, the numbers ending in zeroes are generally the WMO number (*10) in use for that station in the mid-1980s. Numbers not ending in a zero have generally been assigned by CRU or may have originated from other sources. Stations that are listed after number 988360 are stations for which CRU has assigned numbers, mostly beginning with 72 (so using spare country numbers not officially used by WMO) to 75 (corresponding to stations in the United States). Some WMO IDs have been updated in the 2000s.
It looks like the sixth digit is the GHCN identification. This seems to be the case with Marysville which I checked. They note:
The station temperature data are updated each month, together with some back data for the last couple of years. As the WMO IDs have not all been updated, we have a look-up Table which associates some current WMO station numbers with the earlier values we are using. Updates come from two principal sources [CLIMAT messages exchanged between National Meteorological Services (NMSs) and from the publication Monthly Climatic Data for the World]. Additional updates in near-real time (either monthly or annually) come directly from Australia, Canada, New Zealand, Austria, the Nordic countries and a few others.
The look-up table doesn’t seem to be online.
Some aspects of HadCRU3 are easier to implement than GISS – earlier this year, I was able to track a gridcell series to the Barabinsk station data. With Hansen, you can never track anything. There’s a case for putting some of the Hansen mysteries on hiatus for a while and digging into CRU. The effort in understanding the individual stations is not lost since we’re mostly dealing with GHCN and MCDW data.