The ability of climate models to correctly reproduce clouds and the radiative effects of clouds is vitally important in climate simulations and projections.In this study,simulations of the shortwave cloud radiative ef...The ability of climate models to correctly reproduce clouds and the radiative effects of clouds is vitally important in climate simulations and projections.In this study,simulations of the shortwave cloud radiative effect(SWCRE)using the Chinese Academy of Meteorological Sciences Climate System Model(CAMS-CSM)are evaluated.The relationships between SWCRE and dynamic–thermodynamic regimes are examined to understand whether the model can simulate realistic processes that are responsible for the generation and maintenance of stratus clouds.Over eastern China,CAMS-CSM well simulates the SWCRE climatological state and stratus cloud distribution.The model captures the strong dependence of SWCRE on the dynamic conditions.Over the marine boundary layer regions,the simulated SWCRE magnitude is weaker than that in the observations due to the lack of low-level stratus clouds in the model.The model fails to simulate the close relationship between SWCRE and local stability over these regions.A sensitivity numerical experiment using a specifically designed parameterization scheme for the stratocumulus cloud cover confirms this assertion.Parameterization schemes that directly depict the relationship between the stratus cloud amount and stability are beneficial for improving the model performance.展开更多
基金Supported by the National Key Research and Development Program of China(2017YFC1502202 and 2016YFA0602101)National Natural Science Foundation of China(41875135 and 91637210)
文摘The ability of climate models to correctly reproduce clouds and the radiative effects of clouds is vitally important in climate simulations and projections.In this study,simulations of the shortwave cloud radiative effect(SWCRE)using the Chinese Academy of Meteorological Sciences Climate System Model(CAMS-CSM)are evaluated.The relationships between SWCRE and dynamic–thermodynamic regimes are examined to understand whether the model can simulate realistic processes that are responsible for the generation and maintenance of stratus clouds.Over eastern China,CAMS-CSM well simulates the SWCRE climatological state and stratus cloud distribution.The model captures the strong dependence of SWCRE on the dynamic conditions.Over the marine boundary layer regions,the simulated SWCRE magnitude is weaker than that in the observations due to the lack of low-level stratus clouds in the model.The model fails to simulate the close relationship between SWCRE and local stability over these regions.A sensitivity numerical experiment using a specifically designed parameterization scheme for the stratocumulus cloud cover confirms this assertion.Parameterization schemes that directly depict the relationship between the stratus cloud amount and stability are beneficial for improving the model performance.
