The SURFEXv7.2 land and ocean surface platform for coupled or offline simulation of earth surface variables and fluxes

Abstract

Abstract. SURFEX is a new externalized land and ocean surface platform that describes the surface fluxes and the evolution of four types of surfaces: nature, town, inland water and ocean. It is mostly based on pre-existing, well-validated scientific models that are continuously improved. The motivation for the building of SURFEX is to use strictly identical scientific models in a high range of applications in order to mutualise the research and development efforts. SURFEX can be run in offline mode (0-D or 2-D runs) or in coupled mode (from mesoscale models to numerical weather prediction and climate models). An assimilation mode is included for numerical weather prediction and monitoring. In addition to momentum, heat and water fluxes, SURFEX is able to simulate fluxes of carbon dioxide, chemical species, continental aerosols, sea salt and snow particles. The main principles of the organisation of the surface are described first. Then, a survey is made of the scientific module (including the coupling strategy). Finally, the main applications of the code are summarised. The validation work undertaken shows that replacing the pre-existing surface models by SURFEX in these applications is usually associated with improved skill, as the numerous scientific developments contained in this community code are used to good advantage.

Using MODIS land surface temperatures and the Crocus snow model to understand the warm bias of ERA-Interim reanalyses at the surface in Antarctica

“…Within the modeling platform SURFEX (EXTernalized land and ocean SURFace platform) (Masson et al, 2013), the Crocus snowpack model (Brun et al, 1992;Vionnet et al, 2012) was run in a stand-alone mode, using meteorological forcing data from ERA-Interim. The ERA-Interim total precipitation was turned into snowfall at temperatures below 1 • C and into rainfall above.…”

Inclusion of vegetation in the Town Energy Balance model for modelling urban green areas

“…Based on the tiling approach, SURFEX (SURFace EXTernalisée in French) is the externalised land-surface modelling system (Salgado and Moigne, 2010;Masson et al, 2012) that has been developed at Meteo-France. It can be run in a coupled way with different meteorological models, e.g., the Meso-NH research model (Lafore et al, 1998) or the AROME weather forecasting model (Seity et al, 2011), as well as in offline configuration using atmospheric forcing coming from analyses or observation at a given height above the top of the canopy.…”

Observation de la végétation depuis l'espace

“…Cela est indispensable afin de bien représenter l'impact des événements extrêmes comme les sécheresses agricoles. Aujourd'hui, les indicateurs de sécheresse agricole produits par Météo-France proviennent de simulations numériques de l'humidité du sol réalisées grâce à la plateforme de modélisation Surfex (surface externalisée) (Masson et al, 2013). Des recherches ont été menées af in d'évaluer l'impact de l'intégration de données satellitaires dans Surfex sur le suivi des sécheresses.…”