On Soil Moisture, Plants, and the Atmospheric Boundary Layer

The terrestrial water balance and the related soil-moisture dynamics affect vegetation growth, which in turn controls the water and energy fluxes between the land and the atmosphere. Using minimalist models of these coupled dynamics, we explore the role of photosynthesis types and plant-water stress on the diurnal evolution of the atmospheric boundary layer. We focus on the initiation of moist convection taking place when the atmospheric boundary layer reaches the lifting condensation level (LCL) in conditions of high convective available potential energy (CAPE). We show how transpiration regimes of different photosynthetic types (e.g., C3, C4 and CAM) and main crops may imply different controls of such occurrences, with potential feedbacks on the regional water cycle.