The 'too few, too bright' tropical low-cloud problem in CMIP5 models

摘要: Previous generations of climate models have been shown to under-estimate the occurrence tropical low-level clouds and over-estimate their radiative effects. This study analyzes outputs from multiple participating in Fifth phase Coupled Model Intercomparison Project (CMIP5) using Cloud Feedback Observations Simulator Package (COSP), compares them with different satellite data sets. Those include CALIPSO lidar observations, PARASOL mono-directional reflectances CERES fluxes at top atmosphere. We show that current state-of-the-art predict overly bright low-clouds, even for a correct low-cloud cover. The impact these biases on Earth' radiation budget, however, is reduced by compensating errors. tendency cover overestimate mid-and high-clouds above low-clouds. Finally, we poorly represent dependence vertical structure low-clouds large-scale environmental conditions. implications this 'too few, too problem' sensitivity model development are discussed. Citation: Nam, C., S. Bony, J.-L. Dufresne, H. Chepfer (2012), bright' problem CMIP5 models, Geophys. Res. Lett., 39, L21801, doi: 10.1029/2012GL053421.