The ISBA land surface parameterisation scheme

An updated description of the land surface scheme ISBA (Interaction Soil Biosphere Atmosphere) is given. Recent improvements mostly concern the evaporation from bare soil, the inclusion of gravitational drainage, a continuous formulation of soil transfer coefficients for heat and moisture, and a modification of the surface drag coefficients. Validations of this scheme undertaken at local scale using data set from various field campaign experiments are summarized. The ISBA scheme has been implemented in mesoscale and global scale models. Mesoscale modelling was used to define effective parameters taking into account sub-grid scale heterogeneities of the surface. Finally, developments on soil moisture initialization for potential applications to numerical weather prediction are described.