SST perturbation experiments in the CSU general circulation model: Impact on simulated cloud types

The impact of increased sea-surface temperatures (SST) on upper-tropospheric clouds using ISCCP simulators that distinguish between the response of optically thin and thicker clouds was investigated. It is observed that with increasing SST, low-level cloudiness was increased and high-level cloudness was decreased. Large-scale water vapor, cloud water, and cloud ice are entrained at the bottom and sides of the convective updrafts while in-cloud water, cloud ice, and snow are detrained at cloud-tops. It was also observed that the limited response of thick clouds resulted due to the deficiencies in the parameterized physics, for the tropics.