The numerical model ARPEGE is a global and spectral general circulation model. Historically, it has been developed for "operational numerical weather forecast" by Météo-France in collaboration with ECMWF (Reading, U.K.). Its climate version (ARPEGE-Climate) has been developed in the 90s (Déqué et al., 1994). ARPEGE-Climate became the atmosphere part of the CNRM "earth modelling system" which couples different components of the climate system (atmosphere, ocean, land-surface, sea ice). The earth modelling system used in the IPCC-AR4 report (2007) by CNRM is described by Salas y Melia et al. (2005). The ARPEGE grid can be tilted and stretched in changing the position of the pole and in increasing the horizontal resolution over an area of interest. This zoom ability allows regional climate studies with ARPEGE-Climate (Déqué and Piedelievre, 1995; Gibelin and Déqué, 2003). For example, the "Medias" configuration of ARPEGE-Climate version 4 has its pole in the Tyrrhenian Sea (between Italy and Corsica) and a stretching factor equal to 2.5. A resolution of about 50 km is thus obtained for the Europe-Mediterranean-North Africa area. A comprehensive documentation of the model can be found for the following versions:


  • The studies carried out cover: Study of global climate process (indian and african moonsoon, ENSO, NAO)
  • Study of regional climate process (Mediterranean cyclogenesis, extreme events, tropical cyclones, Mediterranean thermohaline circulation)
  • Climate change scenario : global and regional downscaling
  • Seasonal forecast
  • Climate model intercomparaison projects
  • Dynamical downscaling of the ERA40 reanalysis through spectral nudging
  • Forcing (and coupling) of Mediterranean ocean models
  • Forcing of hydrological models in France


The develpment of the model dynamics and physics is mainly done with ECMWF, the other CNRM reserch groups (GMAP, GMME) and the IPSL institute. However ARPEGE-Climate is used worldwide by other climate research lab.

 Publications associated with this model

Déqué M., Dreveton C., Braun A., Cariolle D. (1994) : The ARPEGE-IFS atmosphere model: a contribution to the French community climate modelling. Climate Dynamics 10:249-266

Déqué M. and Piedelievre J.-P. (1995) : High-Resolution climate simulation over Europe. Climate Dynamics 11:321-339

Gibelin A.-L. and Déqué M. (2003) : Anthropogenic climate change over the Mediterranean region simulated by a global variable resolution model. Climate Dynamics 20:327-339

Salas y Mélia D., Chauvin F., Déqué M., Douville H., Guérémy J.F., Marquet P., Planton S., Royer J.F., Tyteca S. (2005) : Description and validation of CNRM-CM3 global coupled climate model. Note de centre GMGEC (internal publication), CNRM, 103.