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CRUTEM4: Version Numbering Scheme

CRUTEM4 Version Numbering

A new version numbering scheme has been introduced with the most recent update of the CRUTEM4 dataset. The CRUTEM4 version numbers take the following format:

The uses of X, Y, Z and θ in the versioning scheme are as follows:

- Major dataset version number. For CRUTEM4 this number is 4.
- Major update to methodology, code or source data. For example, Y would be updated with the inclusion of data sources that were not previously present in the dataset, such as the inclusion of a newly homogenised data source or if there is a major update or addition to the code used to produce the dataset.
- Minor update to methodology, code or source data. For example, Z would be updated when historical data sources already included in the dataset are updated (such as adding an extra year of data to an existing source that isn't updated on a monthly basis) or for minor updates to existing code.
- Reserved for future use.

Changes to the CRUTEM4 code or data sources will result in an update of the CRUTEM4 version number.

Version numbers are not increased with each monthly update of the dataset. Information on changes to data in monthly updates is described through the use of field status flags.

Field Status Flags

Monthly updates to CRUTEM4 operate on a rolling 12 month update window running up to and including the most recent complete calendar month. These updates add station data for these months to the CRUTEM4 database from CLIMAT messages recieved over the Global Telecommunication System (GTS) and from Monthly Climatic Data for the World (MCDW) publications. Field status information is included in the CRUTEM4 field metadata to indicate whether or not monthly fields are liable to change in future updates.

Finalised - "f"
- Monthly fields marked with a status flag of "f" are finalised and will not be updated again under the current CRUTEM4 version number.
Preliminary - "p"
- Monthly fields marked with a status flag of "p" are preliminary and may be updated in a future monthly update.

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