Low cloud reduction in a greenhouse‐warmed climate: Results from Lagrangian LES of a subtropical marine cloudiness transition

摘要: Lagrangian large-eddy simulations of a composite stratocumulus to cumulus transition case over the subtropical northeast Pacific Ocean are subject perturbed forcings that isolate cloud response CO2, overall tropical warming, and increased inversion stability subsidence regions. These show surface warming 4 K induces substantial thinning via thermodynamic mechanism: layer humidity flux in warmer climate an entrainment liquid-flux adjustment dries layer, whether well mixed or coupled. A radiative mechanism amplifies this response: emissivity free troposphere due CO2 water vapor reduces driving turbulence stratocumulus-capped boundary layer; thinner accompanies less turbulence. In combination, quadrupling greatly reduce low weaken simulated shortwave effect by 50%. Large increases regions could counter much cloudiness reduction.