Verification of land–atmosphere coupling in forecast models, reanalyses, and land surface models using flux site observations

Models clearly underrepresent the feedback of surface fluxes on boundary layer properties (the atmospheric leg of land-atmosphere coupling) and may overrepresent the connection between soil moisture and surface fluxes (the terrestrial leg).

Models generally underrepresent spatial and temporal variability relative to observations, which is at least partially an artifact of the differences in spatial scale between model grid boxes and flux tower footprints. All models bias high in near-surface humidity and downward shortwave radiation, struggle to represent precipitation accurately, and show serious problems in reproducing surface albedos. These errors create challenges for models to partition surface energy properly, and errors are traceable through the surface energy and water cycles.