The Role of Land-Surface Dynamics in Climate Persistence and Convective Extremes

The properties governing atmospheric convection, which can produce heavy rainfall and severe weather events, depend on both land-surface characteristics and atmospheric conditions. This work develops a stochastic, coupled plant–soil–atmosphere model that treats atmospheric drivers of moist convection, such as convective available potential energy (CAPE), as functions of the soil–vegetation surface. Further, we link trajectories of these atmospheric and surface variables, including rainfall intensity, to changes in functional plant type (i.e., response to drought stress) and soil type. This enables the realization of steady-state probability distributions of relevant ecohydrological quantities, including soil moisture, plant water potential, and CAPE. From this dynamical systems perspective, the probability of rainfall is conditioned on the terrestrial surface state. Therefore, the wet–dry switching that influences climatic persistence in convection-dominated regions can be directly related to soil moisture. This formulation provides a framework for understanding how very large CAPE and intense rainfall can emerge under specific combinations of antecedent soil moisture, land-surface fluxes, and free-atmospheric conditions.