The Role of Deep Convection in Establishing the Isotopic Composition of Water Vapor in the Tropics

We employ a three-dimensional large eddy simulation with bin-resolved microphysics to simulate the distribution of water isotopomers within deep convection. Deep convection produces vertical profiles of HDO vapor that deviate significantly from the Rayleigh distillation model. These deviations are caused by the lofting of HDO-rich cloud ice within convective updrafts and the subsequent sublimation of this ice in cumulonimbus anvils. The model results agree with recent remote sensing observations of the tropical transition layer.