Met Office

Met Office seasonal and climate models

The Met Office Hadley Centre develops configurations of the Met Office Unified Model which are suitable for seasonal, decadal and centennial climate predictions.

These are usually lower resolution than the models used for day to day weather forecasting, and include ocean and sea-ice components coupled to the atmosphere model in order to represent the full coupled climate system. Additional processes associated with atmospheric chemistry and the ecosystem are included in "Earth System" configurations only (due to computational cost). Current operational configurations are indicated in the table below, with higher horizontal and vertical resolution versions under development.

Seasonal and climate configurations of the Unified Modelling system
ConfigurationAtmosphere ResolutionOcean ResolutionInitial ConditionsTypical Run Length
Seasonal

85 levels to 85 km

1.875° x 1.25°
~140 km at mid-latitudes

75 levels

1.0° x 1.0°(increasing smoothly from 30°N/S to 0.33° at equator)

Atmos: Met Office global analyses

Ocean and sea ice (concentrations): data assimilation based on  FOAM

42-member ensembles of ~7 month runs, updated monthly
Decadal

19 levels to 40 km

3.75° x 2.5°
~280 km at mid-latitudes

20 levels

1.25° x 1.25°

Atmos: ECMWF global analyses

Ocean: data assimilation of observed anomalies

10-member ensembles of ~10 year runs, updated annually
Centennial38 levels to 40 km1.875° x 1.25°
~140 km at mid-latitudes

40 levels

1.0° x (1.0° increasing smoothly from 30°N/S to 0.33° at equator)

Atmos: Met Office global analyses representative of current climate

Ocean: Levitus present-day observed ocean conditions

Sea ice: present-day conditions taken from previous climate model 20th century simulation

~100s years
Earth System38 levels to 40 km1.875° x 1.25°
~140 km at mid-latitudes		40 levels1.0° x (1.0° increasing smoothly from 30°N/S to 0.33° at equator)

Atmos: Met Office global analyses representative of current climate

Ocean: Levitus present-day observed ocean conditions

Sea ice: present-day conditions taken from previous climate model 20th century simulation

~100s years
Regional climate19 levels0.22° x 0.22° (~24km) to 0.44° x 0.44° (~50km)
limited area		- Met Office global analyses;
ECMWF reanalyses used at lateral boundaries 		~10 years, or up to 150 years for climate change runs

Details of what is involved in the different types of predictions is available on the explanation of seasonal and climate modelling page.

Climate change predictions

Centennial climate predictions from the Met Office Hadley Centre have been included in all of the climate change Assessment Reports of the Intergovernmental Panel on Climate Change. The named climate configurations used in these reports were:

  • Second Assessment Report (1995): HadCM2
  • Third Assessment Report (2001): HadCM3
  • Fourth Assessment Report (2007):  HadGEM1

The Met Office Hadley Centre will also be contributing runs from the HadGEM2 family of models to the IPCC Fifth Assessment Report planned for 2013.

Current projects

Current projects with which the Unified Model climate configurations are involved include:

  • Development of the HadGEM3 family : a family of climate models which uses the NEMO ocean model and CICE sea-ice model components and includes configurations with significantly increased horizontal and vertical resolution.  It is planned that climate configurations of the MetUM at all timescales will move to the HadGEM3 family over the next few years.
  • ENSEMBLES: an ensemble prediction system for climate change based on the principal state-of-the-art, high resolution, global and regional Earth System models developed in Europe;
  • UK Climate Projections ( UKCP09): using cutting-edge science to understand how the UK's climate may change over this century;
  • Providing Regional Climates for Impacts Studies (PRECIS)]: a regional climate modelling system which can be applied to any area of the globe to generate detailed climate change projections;
  • Joint UK Land Environment Simulator ( JULES): a joint project with NERC which uses the Met Office Surface Exchange System, a computer model which represents the land, to help predict climate change impacts on land;
  • Joint Weather Climate Research Programme ( JWCRP): a Met Office/NERC initiative to strengthen the UK's world-leading reputation in climate science, partly through development of better modelling tools;
  • Climateprediction.net: a distributed computing project to produce predictions of the Earth's climate up to 2080 and to test the accuracy of climate models.
Last Updated: 12 April 2012

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