Research Progress of Fractionation Mechanism of Stable Hydrogen and Oxygen Isotope during Water Body Evaporation

Evaporation is the most significant process that affects the isotopic transport of surface water. The study of mechanisms and modeling of the evaporation process has a very important practical significance in improving the isotopic analysis method. This paper reviews the international development of the mechanism of hydrogen and oxygen stable isotopic fractionation and model. It indicates that as the most ideal tracers of hydrologic cycle, stable hydrogen and oxygen isotopes have their unique and irreplaceable functions. However, field experiments of evaporation and further research are limited by the complexities of kinetic flow in the atmosphere and observation technique. Modeling and experiments are commonly based on the assumption that evaporating water is well-mixed, and isotopic stratification in liquid is not considered by most laboratories. While it dose affect. Flow disturbance in the atmosphere is the most uncertain factor for isotopic fractionation in the process of evaporation. The modeling example shows isotopic evaporation line of natural water can be simulated properly while detailed simulations are limited by the lake of observational data of isotopic diffusion processes in both air phase and liquid phase.