Spatial distribution of the oxygen-18 in precipitation in China based on a new empirical model

Modeling the oxygen-18 in precipitation based on regional topography and meteorological factors is helpful to constrain missing isotopic data in some regions that is required for many paleoclimate, eco-hydrological and atmospheric circulation studies. Therefore, the relationship between δ 18 O in precipitation ( δ 18 O PPT ) and the affecting factors need to be thoroughly understood. We present a model considering the combined effects of temperature, altitude, and latitude on the spatial variability of annual average of stable isotopes in precipitation across China. This new model performed significantly better (P<0.05) than the widely used Farquhar and Bowen & Wilkinson models. Our model allows modelling the spatial distribution of isotopes in precipitation depending on temperature variation. The residuals of presented model did not significantly correlate with altitude. Based on the model and residuals, a high-resolution map of annual average δ 18 O ppt across China was generated. δ 18 O ppt decreased from low toward high latitudes and from low towards high altitudes area. The model application provides important information for ancient climate, hydrological cycle and water vapor sources studies.