Wave-Permeable Lateral Boundary Conditions for Convective Cloud and Storm Simulations

Abstract

Linearized conditional instability theory is used to test the effects of lateral boundary conditions on convective elements. By this theory the outer environment of an amplifying convective element acts like an internal gravity wave with imaginary horizontal wavelength which propagates outward with a wave velocity slightly greater than that of hydrostatic modes. Lateral boundary conditions based on wave radiation principles are therefore appropriate and can eliminate the growth constraints produced by rigid or periodic boundaries.