Stabilization of Atmospheric Boundary Layer and the Muted Global Hydrological Cycle Response to Global Warming

The global precipitation in global warming simulations increases at 1~3 % /K, much smaller than 6~6.5 % /K as the Clausius-Clapeyron (C-C) relation indicates. However the model simulations suggest that the fractional decrease of the Bowen Ratio over global ocean surface in the simulations follows the C-C relation. It is further shown, based on the analysis on the change of the Bowen Ratio, that the stabilization of atmospheric boundary layer (ABL) in response to global warming is one of the main factors responsible for the muted increase in global precipitation, through its confinement on the increase of evaporation. The ABL stabilization mechanism for the muted increase in the global hydrological cycle in response to global warming is physically consistent with other two proposed mechanisms, namely, atmospheric energy constraint and the reduction of convective mass flux.