The large-scale, long-term coupling of temperature, hydrology, and water isotopes

Although it is known to be a simplification, the relationship is often explained by invoking a single condensation pathway with progressive distillation to the temperature at the location of the ice core. In reality, the physical factors are complicated, and recent studies have identified robust aspects of the hydrologic cycle's response to climate change that could influence the isotope-temperature relationship.

In this study, we introduce a new zonal-mean isotope model derived from radiative transfer theory and incorporate it into a recently developed moist energy balance climate model (MEBM), thus providing an internally consistent representation of the physical coupling between temperature, hydrology, and isotope ratios in the zonal-mean climate. The isotope model reproduces the observed pattern of meteoric delta O-18 in the modern climate and allows us to evaluate the relative importance of different processes for the temporal correlation between delta O-18 and temperature at high latitudes.