资源环境科技发展态势分析平台

Tropical ascent area (A(a)) and high cloud fraction (HCF) are projected to decrease with surface warming in most Coupled Model Intercomparison Project Phase 5 (CMIP5) models. Perturbing deep convective parameters in the Community Atmosphere Model (CAM5) results in a similar spread and correlation between HCF and A(a) responses to interannual warming compared to the CMIP5 ensemble, with a narrower A(a) corresponding to greater HCF reduction. Perturbing cloud physics parameters produces a comparatively smaller range of A a responses to warming and a dissimilar HCF-A(a) relation to that in CMIP5; a narrower A(a) corresponds to less HCF reduction, likely due to cloud radiative effects. A narrowing of A(a) corresponds to a regime shift toward stronger precipitation in both experiments. We infer that model differences in deep convection parameterization likely play a greater role than differing cloud physics in determining the diverse responses of A(a) and HCF to warming in CMIP5.