Climate Model Evaluation Using Cloud Observations and Implications for Climate Sensitivity

We present an evaluation of climate model simulated clouds and related moisture fields using satellite observations. A quantitative scoring system is employed and a regime-dependent error diagnostics is performed. We found that the model spreads and their differences from the observations are much larger in the upper troposphere than in the lower or middle troposphere. We show that cloud parameterization errors contribute predominantly to the total errors for all models. Also, the model performance in clouds and moisture simulations are highly correlated with model estimates of climate sensitivity. The linkages between large-scale circulation and cloud distributions in present-day climate and under future climate change are explored.