Advances in simulating atmospheric variability with the ECMWF model: From synoptic to decadal time‐scales

Abstract Advances in simulating atmospheric variability with the ECMWF model are presented that stem from revisions of the convection and diffusion parametrizations. The revisions concern in particular the introduction of a variable convective adjustment time‐scale, a convective entrainment rate proportional to the environmental relative humidity, as well as free tropospheric diffusion coefficients for heat and momentum based on Monin–Obukhov functional dependencies. The forecasting system is evaluated against analyses and observations using high‐resolution medium‐range deterministic and ensemble forecasts, monthly and seasonal integrations, and decadal integrations with coupled atmosphere‐ocean models. The…