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

0.83° x 0.55°
~50 km at mid-latitudes

75 levels

0.25° x 0.25°

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

85 levels to 85 km

0.83° x 0.55°
~50 km at mid-latitudes

75 levels

0.25° x 0.25°

Atmos: ECMWF global analyses

Ocean: data assimilation of observed full fields

10-member ensembles of ~5 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:

Last updated: 24 September 2014

Seasonal and climate versions of the Unified Model

  • GloSea5
    GloSea5 is the seasonal prediction system developed and run operationally at the Met Office.
  • DePreSys
    DePreSys is the decadal prediction system developed and run at the Met Office.
  • HadCM3
    HadCM3 is a coupled climate model that has been used extensively for climate prediction, detection and attribution, and other climate sensitivity studies.
  • HadCM2
    HadCM2 was the first Met Office Hadley Centre coupled model developed under the Unified Modelling system.
  • HadGEM3 family
    The HadGEM3 family of climate models represents the third generation of HadGEM configurations and includes the NEMO ocean model and CICE sea-ice model components.
  • HadGEM2 family
    The HadGEM2 family of climate models represents the second generation of HadGEM configurations, with additional functionality including a well-resolved stratosphere and Earth System components.
  • HadGEM1
    HadGEM1 is the first in a new generation of coupled climate models incorporating a non-hydrostatic, fully compressible, deep atmosphere formulation with a semi-implicit semi-Lagrangian time integration scheme.