CRUTEM5.0 file formats for the station data

The station data are provided in two formats:

(1) Met Office netCDF files, which contain the station data with the normals and standard deviations
for each station in each station's file.

netCDF files are self-describing, so their format is not explained here.

(2) CRU text files, which contain the station data but the normals and standard deviations are stored
text files that are separate to the station data.

This readme explains the format of these text files.


(2a) CRU text file for the station data

Filename is:

<archive_id>.stat4post.txt

where <archive_id> indicates the input station database.  For example: CRUTEM.5.0.1.0

and 'stat4' indicates that this is a station data file in the same format as used for CRUTEM4

and 'post' indicates that this file is after (post) application of outlier removal and other quality
control steps.

The format is the same as used for CRUTEM4 by CRU and is described here:

https://crudata.uea.ac.uk/cru/data/temperature/crutem4/station-data.htm

Missing codes for station metadata are:
latitude: -999
longitude: -9999
elevation: -9999


(2b) CRU text file for the station normals

Filename is:

<archive_id>.normals5.txt

This file contains the normals, one row per station. Columns are:

1 CRU station ID (often the same as the WMO ID)
2-3 First year, last year of the station data
4-5 First year, last year  used for calculating the normal
6-17 Twelve normals for Jan to Dec, degC (not degC*10), missing normals are -999.000
18 Source code (1=missing, 2=Phil Jones's estimate, 3=WMO, 4=calculated here, 5=calculated previously)
19-30 Twelve values giving the % data available for computing each normal from the 1961-1990 period

The source code is set to 1 only if all 12 normals are missing.
If a station has partially-missing and partially-present normals, the source code for the available
normals is given.
If a station has normals for some months from one source and for other months from a different source,
the source code is set to the most commonly used source.


(2c) CRU text file for the station standard deviatins

Filename is:

<archive_id>.sd5.txt

This file contains the standard deviations (SDs). Columns are the same as for the normals file. The % data
available is now for the 1941-1990 period over which the SDs are calculated.