资源环境科技发展态势分析平台

Instantaneous satellite cloud top height (CTH) data from Moderate Resolution Imaging Spectroradiometer and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation, as well as planetary boundary layer (PBL) heights corresponding to the minimum refractivity gradient (PBLHN) from GPS radio occultation over the Southeast Pacific, are jointly used for the first time to assess the ability of three versions of National Center for Atmospheric Research Community Atmosphere Model 5 (CAM5) to simulate low-level cloud extent and boundary layer heights. Observed CTH and PBLHN match most closely in the stratocumulus and stratocumulus-to-cumulus transition region, but CTH becomes lower than PBLHN since not all trade cumulus clouds reach the inversion. Simulated CTH and PBLHN are too shallow, but clouds with a new subgrid low cloud parameterization, Cloud Layers Unified by Binormals (CAM5-CLUBB), have a reduced bias, with the CTH-PBLHN distribution from Hi-Res CAM5-CLUBB, the most similar to observations. For PBLHN > 2.7 km, the base CAM5 model shows a bimodal cloud structure and surface-to-500 hPa ascent not seen in observations and European Centre for Medium-Range Weather Forecasts Re analysis Interim data.