The Climate Impacts LINK Project (known just as LINK) provides climate simulations from the Met Office Hadley Centre (MOHC) to the UK and international academic communities. The data includes climate runs from a range of MOHC models including HadCM2, HadCM3, HadRM2, HadRM3 and HadGEM1.

The current generation of MOHC models is the HadGEM suite. Previously the HadCMX suite produced both global datasets (CMx) and regional model data (RMx). HadCM2, HadCM3 and HadGEM1 are global coupled atmosphere-ocean models. HadCM2 was used in the IPCC Second Assessment Report, and was followed by HadCM3, the model used in the Third Assessment Report. HadCM3 included an improved representation of the atmosphere and ocean physics compared to HadCM2. In particular the improvement in physics mean that HadCM3 has a reasonable, stable climate without the use of a flux correction. HadGEM1 is yet higher in spatial resolution and contributed most recently, along with HadCM3, to the Fourth Assessment Report.

HadRM2 and HadRM3 are high resolution atmospheric models run over the European domain. HadRM3 simulations were used to develop the scenarios underpinning the UKCIP02 Scientific Report on Climate Change Scenarios for the United Kingdom. Additional HadRM3 ensemble simulations are being used to generate probabilistic projections of climate change for the UK 21st Century Climate Scenarios (2008) [also known as UKCIP08].

LINK was established by the UK Department for Environment, Food and Rural Affairs (Defra) in 1991, and initially delivered by the Climate Research Unit (CRU) at the University of East Anglia (UEA). In 2002, the volume of data became large enough that CRU sub-contracted the British Atmospheric Data Centre (BADC) to handle the data, and CRU managed the ancillary information. In 2006, the BADC took over the main contract, and now sub-contract to the MOHC to provide the substantial quantity of data and additional ancillary information describing the simulations.

LINK was initially focussed on the climate impacts community only and datasets were selected with that specific community in mind. The incorporation of the LINK datasets into the BADC infrastructure has allowed exploitation of synergies with other projects to expand both the size of the user community and the volume and number of datasets that can be delivered. With MOHC support the efficiencies of data extractions and services that can be provided to users has been greatly enhanced.

The LINK project acts as an umbrella activity under which the various MOHC datasets are now held. These are being archived as individual BADC datasets even although applications for LINK data will allow users to access multiple model datasets where the conditions of use allow it. Users can also browse the BADC catalogue under the LINK directory to find symbolic links to these other datasets from a single location.

The data is all stored in Met Office pp-format. Users wishing to access the data directly in pp-format can download the files via FTP or the data browser.

27/02/13 Additional Perturbed Physics Ensemble data - African temperature and precipitation

Data from two perturbed physics ensembles developed by the Met Office Hadley Centre as part of the QUMP (Quantifying Uncertainty in Model Predictions) project. These data were used to investigate changes in African temperature and precipitation associated with global warming for a special issue on the future of African rainforests. See the description document for more details.

07/12/07 HadCM3 data re-extracted

The BADC are in the process of re-extracting HadCM3 data from the Met Office archive. These data are cuurently available via the BADC FTP server at /badc/hadcm3/data.

19/12/07 LINK status page added

A web page describing the current status of the model data extractions under LINK is now available at http://badc.nerc.ac.uk/data/link/link_status.html

08/10/07 UM Model naming convention.

The Met Office are standardising the way their Unified Model should be referred to:

The Met Office Unified Model is a registered trademark. The Met Office must be acknowledged in any reproduction of data, publication of papers, reports, literature to customers or presentations arising out of the use of the software using: "Met Office Unified ModelTM (UK)".

Full details are given in http://badc.nerc.ac.uk/data/um/UM_Naming_Convention.html.

Access to the Climate Impacts LINK project data at the BADC is restricted. The application for access to the data now includes a specific "Conditions of Use" agreement (currently under review)t, which can be completed on-line. Once your application has bee authorised, you will be given access to these datasets via a Web account. Details of your account will be sent by e-mail. To apply for access to this dataset, please follow this link

The Met. Office LINK data are now available to registered LINK users. Please note that this dataset is still in the process of being populated from the original Met Office archive. These data are stored as binary PP files. Please follow this link to access the archive

Additional information on the structure of the LINK HadCM3 archive is available at: http://badc.nerc.ac.uk/data/link/model_runs.html . This also describes the filenaming convention used at the BADC for the individual pp files.

The current status of the model data extractions under LINK is now available at http://badc.nerc.ac.uk/data/link/link_status.html

Data extracted by the BADC from the Met Office is usually kept in their binary pp format, details of which are available here.

This site also contains information on technical aspects of using the data held at the BADC, including information about the different model runs, interpreation of results, and associated publications which have used LINK data .

A public catalogue of the data supplied to the BADC is currently being populated at GCMD , and can be found under "models" -> "Met Office Hadley Centre" ->search for "hadgem1" (direct link). Over time, this will also include other datasets which can be made available by the Met Office and requested by users.

Some information regarding the actual model runs themselves is also available:

• HadCEM

• A community workspace has been set up at the BADC to allow information to be exchanged by LINK users.
• The interactions between climate change and tourism are discussed here.
• The UK Climate Impacts Programme (UKCIP) provides scenarios that show how our climate might change and co-ordinates research on dealing with our future climate.
• The DEFRA Climate Change web page provides information on climate change; it's causes, how the world and the UK will be affected, what is being done to tackle the effects of climate change, and how to reduce greenhouse gas emissions.
• The BRIDGE (Bristol Research Initiative for the Dynamic Global Environment) web site makes both model and paleo data available, and is mainatined by Paul Valdes at Bristol University.
• The COAPEC Dataset at the BADC.
• The HiGEM Dataset at the BADC.
• UNIDATA CF Metadata Conventions.
• The HadISST dataset at the BADC.

General queries about these pages and access to the data should be directed to the BADC support line. Your query should be answered within one working day. When follow-up work is required, the BADC support will carry out the work as quickly and efficiently as possible, and in any case, the user will be kept informed of progress.