THORPEX is a ten-year WMO research programme to accelerate improvements in the accuracy of one-day to two-week high-impact weather forecasts for the benefit of society, the economy and the environment.
More about the Met Office contributions to the THORPEX research programme
The Met Office played a leading role in the Atlantic THORPEX Observing System Test (Atlantic-TOST), which tested whether additional targeted observations could be used to reduce significant forecast errors.
More about Atlantic-TOST observation targeting

GEO promotes the development of a comprehensive, co-ordinated, and sustained Earth observation system, among governments and international organisations, to significantly advance our collective ability to understand and address global environmental and economic challenges. Its aim is to develop a framework and implementation plan for building systems. The Met Office is active in several of the groups.
More about GEO

Argo will be a global array of 3,000 free-drifting profiling floats to measure the temperature and salinity of the upper 2,000 m of the ocean. Argo data are used in operational ocean models, coupled seasonal forecasting models and will help in detecting climate change in the oceans.
More about the Argo programme

GCOS is intended to be a long-term, user-driven operational system capable of providing the comprehensive observations required for monitoring the climate system, for detecting and attributing climate change, for assessing the impacts of climate variability and change, and for supporting research toward improved understanding, modelling and prediction of the climate system. It addresses the total climate system including physical, chemical and biological properties, and atmospheric, oceanic, hydrologic, cryospheric and terrestrial processes.
More about GCOS

The UK Regional Specialised Met. Centre (RSMC) is operated from the Met Office headquarters in Exeter. RSMC Exeter and RSMC Toulouse have joint responsibility for Environmental Emergency Response requirements in World Meteorological Organization (WMO) regions VI and I which covers Africa and Europe. RSMCs exist to provide advice in the event of a nuclear accident.
More about the RSMC

A group of European national meteorological services with the aim of closer collaboration in the development of techniques for short-range weather prediction.
More about SRNWP

An international project using wind profilers across Europe.
More about CWINDE

The GRAS Meteorology SAF is a EUMETSAT-funded project that develops an operational radio occultation system responsible for delivering temperature, pressure, and humidity profiles in real time, software products for numerical weather prediction models and for carrying out related research. The project is hosted by the Danish Meteorological Institute.
More about the GRAS SAF

The NWP SAF is a EUMETSAT-funded project that exists to co-ordinate research and development efforts among the SAF partners to improve the interface between satellite data and NWP for the benefit of EUMETSAT member states.
More about the NWP SAF

PRISM is a research project supported by the European Commission under the Fifth Framework Programme. The project goals include the development of a set of portable climate community models and associated diagnostic software under standardised coding conventions.
More about PRISM

The EUCOS Composite Observing System (EUCOS) aims to establish and operate a truly European observing network under the auspices of the European Meteorological Network (EUMETNET), to deliver increased efficiency leading to better-quality numerical and general forecasts, initially on a European scale.
More about EUMETNET Composite Observing System (EUCOS)

The Met Office run one of two GCCs (Global Collecting Centres) within the Marine Climatological Summaries Scheme (MCSS) under the World Meteorological Organization's (WMO) Marine Meteorology Programme. This is coordinated by the Joint WMO/IOC Technical Commission for Oceanography and Marine Meteorology (JCOMM).
More about Marine Meteorology

The Met Office participates in several EU Framework Programmes which have led to advances in the science of meteorology, and the development of numerical weather prediction and climate simulation modelling. The Met Office is a partner in 12 successful FP6 projects. Some are research and development projects focusing on improving scientific understanding in climatology, oceanography and aviation safety.

Others are:

GMES
The European initiative for Global Monitoring for Environment and Security.

MERSEA
Marine Environment and Security for the European Area - an oceans project.

GEMS
Global and regional Earth-system (atmosphere) Monitoring using Satellite and in situ data.

EURORISK PREVIEW
European risk management for environmental hazards. Prevention, information and early warning.

EUFAR
EUFAR represents European airborne research, which includes transnational access to 23 instrumented aircraft.

SIMDAT
The Met Office is involved in the international SIMDAT project, with the aim of providing a consistent, virtual view of all meteorological data, across federated (ie linked) platforms using Grid technology.

The Global Ocean Data Assimilation Experiment (GODAE) High Resolution SST Pilot Project will provide a new generation of sea surface temperature data products by merging complementary satellite and in situ SST observations in near real time. The Met Office, through the National Centre for Ocean Forecasting (NCOF), is a full partner within GODAE. The GHRSST-PP International Project Office is hosted by the Hadley Centre and jointly sponsored by the European Space Agency (ESA).
More about the GHRSST-PP