French Research in Meteorology

Meteo France - www.cnrm.meteo.fr

The aim of research in Meteorology is to better understand the atmosphere and its behaviours in order to improve the forecasting of dangerous phenomena for the safety of assets and people.

The research centre of Meteo-France (CNRM) is composed of seven research units. Several of them are located in Toulouse:

	Numerical weather forecast
	Climate study
	Study of the atmospheric processes
	Experimentation and instrumentation, airborne measurements with several instrumented aircrafts in Francazal airport.

Two other units are in Grenoble and Brest for the respective studies of snow and the ocean.

The CNRM is at the centre of several networks of national and international laboratories. This research architecture in meteorology allows a permanent exchange of knowledge and scientific skills, and the realization of important research programmes.

Important collaboration exists between Meteo-France and the CNRS (Institut National des Sciences de l'Univers, Laboratoire d'Aérologie, Laboratoire de Météorologie Dynamique; Institut Pierre Simon Laplace…), the Universities, the Centre National d'Etudes Spatiales, and many other institutions and laboratories which are specialized in weather prediction, hydrology, environment, oceanography in France and abroad (e.g. : ECMWF).

The CNRM takes part regularly in major international projects in which it plays an important part (Fastex, MAP, AMMA...), and is also involved with major scientific projects in response to invitations to tender of the European Union (Ensembles, EUFAR, etc.).

A major priority
Indeed, the CNRM has assigned various priorities in the sector of the climate in order to evaluate and understand the impact of human activities on the climate and atmospheric environments, in particular in Europe and France, and in order to develop, several months in advance, a forecasting capacity for large seasonal anomalies (temperatures, rainfalls etc.). A project is also organized in Africa with a coming campaign on African monsoon (AMMA).

Realistic climatic scenarios
The CNRM carries out long duration simulations as part of the programme of intercomparison of climate models organized by the IPCC. For this purpose, it uses scenarios of socio-economic evolution, on a worldwide scale, with simulated constraints on the gas and aerosol emissions.

The climatic models calculate the evolution of previous and future climates for decades of years on a planetary scale. These simulations are supported by joint work of many laboratories and universities (Cerfacs, IPSL), which contribute to build a numerical model allowing the description of the evolution of the atmosphere, ocean, ice cover, vegetation, continental water and snow,at the same time.

Figure 1: a) Observed, analysed and simulated HSI (positive) and CSI (negative) timeseries over North America ; b) Analysed and simulated HSI and CSI timeseries over Europe ; c) Global distribution of near-surface temperature anomalies in 2003 against the 1950-2000 climatology; d) Global simulated correlations between the European HSI and the surface temperatures over 1950-2099. All results are derived from a B2 scenario, with relatively low hypotheses about the amounts of greenhouse gases emitted over the 21st century.

Complex regional impacts
These simulations must also be improved on regional scales (Europe, the Mediterranean sea, West Africa) in order to better evaluate consequences of climate changes on the various socio-economic fields in collaboration with other teams of research. Météo-France thus developed a regional version of the climatic model, Aladin-Climat, which allows the ability to carry out simulations on Western Europe and France. Atmospheric chemistry In parallel to the development of the climatic models, the CNRM develops a model of atmospheric chemistry covering the lower and the upper atmosphere (troposphere and sratosphere) called Mocage. Applied to regional scale, this model makes it possible to predict the air quality up to three days in advance. Applied on a planetary scale, it realistically simulates, in particular, the evolution of the "stratospheric ozone hole".

Seasonal forecasts
The climatic models are also used to research long-term forecasts. By knowing the state of the atmosphere and ocean on a given date, the coupled models make it possible to simulate their evolution and to deduce their general tendencies one or two seasons in advance. Météo-France carries out regular seasonal forecasts, but those are more reliable for the tropics than for the mid-latitudes, and more accurate for temperatures than for precipitation. It is hoped that progress will be achieved through an improvement of the coupling of the ocean and atmosphere within the framework of the Mercator project.

The CNRM deals with many scientific topics at the heart of environmental concerns and is open to the scientific collaborations which are necessary for the achievement of its ambitious goals.

For more information: contact@cnrm.meteo.fr