Modelling climate variability

CLIVAR Climate of the 20th Century and EMULATE projects

Met Office

Researchers at the Met Office Hadley Centre run ensembles of climate model experiments to investigate recent climate variability. Data from a comprehensive range of variables are available from this site for genuine scientific research purposes, including users from the CLIVAR Climate of the 20th Century and EU EMULATE projects.

An ensemble of 12 model integrations for the period 1949-2002 and a further 6 integrations for the period 1869-2002 will be available from this site. The integrations were made with the HadAM3 model forced with observed SST and all well-established climate forcings. A similar ensemble with identical model set up but excluding anthropogenic climate forcings is also available.

'Natural' Forcings
  • sea-surface temperature
  • volcanic aerosols
  • solar variability
  • orbital changes

  • Anthropogenic Forcings
  • greenhouse gas changes
  • atmospheric ozone change
  • sulphate aerosols
  • land-surface changes

  • The following links give access to a series of ready made figures showing standard quantities from the ensembles of integrations and access to downloadable data for meteorological variables. The figures can be viewed but access to the data requires a password. To obtain this password, download the licence agreement, complete and return. Scanned copies of the form sent via email to this address are acceptable. Alternatively, send the completed form to the Climate Variability Group, Hadley Centre, Met Office, FitzRoy Road, Exeter, EX1 3PB, United Kingdom, or fax to +44 (0)1392 885681 marking the cover sheet 'for attention of the Climate Variability Group, Hadley Centre'. Passwords will be issued on acceptance of your completed licence.  

    The data is supplied in .pp format. For an example of how to read this, see our example f90 program. Note that HadISST sea surface temperature data is available from

    Please note that in order to save disk space, the model data is being compressed; it must therefore be uncompressed using gunzip before use. Data from the following experiments has been compressed to date: xacx[ac], xacy[a-f], aekt[b-e].

    Use of this site is subject to terms and conditions.

    Last updated: 11 Aug 2014
    Maintained by: David Fereday
    © Crown copyright