Deuterium in water vapor above the atmospheric boundary layer

Abstract

A model for the isotopic composition of water vapor above the atmospheric boundary layer ispresented. The model includes the effects of isotope fractionation and vertical turbulenttransport of vapor. It utilizes an assumed air trajectory in which an air parcel initially acquireswater vapor over the ocean, rises dry and then moist adiabatically. and finally sinks to theobserved conditions of height, temperature and dew point temperature. Discrepanciesbetween model predictions and actual profiles are shown to have characteristic signatureswhich render the isotopic composition of water vapor of potential value as a dynamic tracer ofatmospheric processes and motions.