Ocean models at the Met Office

The models are generally the result of international scientific community efforts or collaboration between the Met Office and academic groups in the National Partnership for Ocean Prediction (NPOP). Links to the community model homepages are provided within the brief descriptions below.


ERSEM has been developed by researchers at Plymouth Marine Laboratory and is one of the most complex lower trophic-level marine ecosystem models currently in use, including: one bacteria, four phytoplankton and three zooplankton functional groups; a fully resolved diurnal cycle; variable carbon to chlorophyll ratios; independent nutrient pools for carbon, nitrogen, phosphorous and silicate. 


The Hadley Centre Ocean Carbon Cycle Model (HadOCC) is a Nutrient-Phytoplankton-Zooplankton-Detritus (NPZD) ecosystem model with the addition of two components representing carbon in the ocean: dissolved inorganic carbon and alkalinity. The model has been widely used for carbon cycle studies at the Hadley Centre, and is intended for further use in the next generation Hadley Centre coupled Earth System model. This model was designed to investigate both the natural marine carbon cycle and the uptake of anthropogenic CO2 by the ocean and to be used in future projections of climate change to examine how those processes might change.


The Model of Ecosystem Dynamics, nutrient Utilisation, Sequestration and Acidification (MEDUSA) is an "intermediate complexity" plankton ecosystem model designed to address key feedbacks between anthropogenically-driven changes (climate, acidification) and oceanic biogeochemistry. It resolves a size-structured ecosystem of small (nanophytoplankton and microzooplankton) and large (microphytoplankton and mesozooplankton) components that explicitly includes the biogeochemical cycles of nitrogen, silicon and iron as well as the cycles of carbon, alkalinity and oxygen. As such, MEDUSA is broadly similar in structure to Diat-HadOCC but includes several more recent parameterisations such as variable C:chl, ballasted fast-sinking detritus, and a dynamic Si:N ratio.


Nucleus for European Modelling of the Ocean (NEMO) is a community ocean modelling framework owned and maintained by a consortium of institutes including the Met Office. NEMO has a large user community and is used for research and operational applications


The Forecast Ocean Assimilation Model (FOAM) system is an operational ocean analysis and forecast system run daily at the Met Office.  The system consists of various global, regional and shelf seas configurations.  The underlying models/systems used in FOAM are the NEMO physical ocean model, the Los Alamos sea ice model (CICE) and the Nucleus for European Modelling of the Ocean (NEMOVAR) data assimilation system.  The ERSEM marine ecosystem model is also used in the NW European Shelf FOAM configuration.


The Nucleus for European Modelling of the Ocean (NEMOVAR) data assimilation system is a variational scheme which has been developed specifically for use in the NEMO ocean model. The system is being developed jointly by the Met Office, European Centre for Medium- Range Weather Forecasts (ECMWF), CERFACS and Institut National de Recherche en Informatique et en Automatique (INRIA) Laboratoire Jean Kuntzmann (LJK). The system is able to assimilate in-situ temperature and salinity profiles, sea surface temperature, sea level anomaly and sea-ice concentration data. It can be used to produce both 3DVar and 4DVar analyses, and also hybrid ensemble/variational analyses. Features include the use of a diffusion operator for spreading observational information according to spatial correlations, and a multivariate balance operator that accounts for covariances between ocean variables.


To support operational weather forecasting and other applications, we produce sea surface temperature (SST) products in near real time: the Operational Sea Surface Temperature and Sea Ice Analysis (OSTIA), a diurnal SST product and a multi-product ensemble. OSTIA is a gap-free global gridded foundation SST (the temperature free of diurnal variability) product on a 0.05° grid and is produced daily. Associated products include estimates of biases relative to reference instruments and monthly and seasonal averages. Also produced daily are hourly average skin SSTs produced by combining the OSTIA foundation SST with a ‘warm layer’ model (which assimilates SSTs estimated from satellite data) and a ‘cool skin’ model. The Group for High Resolution SST (GHRSST) Multi-Product Ensemble takes various gap-free SST products from around the world as its input, places them on a common grid and produces files containing, amongst other things, the median and standard deviation of the ensemble. All these products are available through the Copernicus Marine Environment Monitoring Service (CMEMS


WAVEWATCH III® is a 3rd generation community wave model developed and maintained by NCEP and contributed to by various national forecast centres internationally.