Post-CMIP5 Model Improvements in Clouds and Water Vapor

Evaluations of CMIP5 Climate Model simulations using satellite measurements showed large spread in modeled clouds and water vapor fields, especially in the upper troposphere. Since then, substantial efforts have been undertaken by modeling groups to improve model performances. Collaborating closely with the modeling teams, we have documented incremental changes of post-CMIP5 model simulated clouds and water vapor and diagnosed their error sources. We focus on model improvements in both clouds and water vapor in the upper troposphere, changes in simulated diurnal cycles of ice clouds and water vapor transport from the upper troposphere to the lower stratosphere. Satellite observational uncertainties and sampling biases are taken into account in quantifying the model-observation differences.