Convection is modelled as buoyant ascent within narrow updrafts, peripheral descent in saturated downdrafts, and compensating subsidence over the remainder of the disturbed area. Excess condensate of the updraft - downdraft system is allowed to evaporate into the subsiding air, generally to maintain or increase the local mixing ratio. It is shown that the action of this model of convection in a region of synoptic scale mean ascent leads to a neutral stratification of the atmospheric lapse rate. The model is parameterised in a multi-level grid model of the atmosphere and integrations demonstrate the rapid synoptic response of the dynamics to boundary layer forcing. The integrations highlight the requirement for diurnal control of the surface temperature and associated heat fluxes over the land.
W. R. Kininmonth (Wed,) studied this question.