Radiative-convective model with an explicit hydrologic cycle: 2. Sensitivity to large changes in solar forcing

摘要: The one-dimensional radiative-connective equilibrium model with an explicit hydrologic cycle introduced in part 1 is used to study the sensitivity of model's atmosphere large changes solar forcing, when various cumulus convection parameterizations are used. As shown by Simpson [1927], Komabayasi [1967], and Ingersoll [1969] concentration absorbing gas temperature dependent, impossible for values forcing larger than a critical value. This result referred as runaway greenhouse. parameterization schemes currently use global climate models (GCMs) employ different assumptions about moistening. causes above which greenhouse occurs be very sensitive scheme employed. Furthermore, using microphysically based proposed Emanuel [1991], we show that depends crucially on microphysics convection. For fixed cloud conditions, occur between approximately 1.22 1.49 times mean value Earth, clear sky it few percent lower. experiments mass flux generally more rapidly adjustment schemes. In addition, inability hard convective produce efficient vertical transport moisture, together saturation requirement occur, leads breakdown radiative-convective equilibria other processes not available provide necessary water vapor.