Development of an atmosphere-land surface coupled isotope circulation model

Precipitation isotopes variability is dominantly controlled by large-scale atmospheric moisture transport processes. It was argued by Yoshimura et al. with the Rayleigh-type isotope circulation model with the model reproduction of daily H218O variability over the sub-tropics, particularly Thailand, and monthly averages at global scales with GNIP (Global Network of Isotopes in Precipitation). However, there remain some discrepancies between the observation and the simulations. It probably implies that we cannot neglect some effect of land surface processes on the variability of precipitation isotopes; in particular. The effect on diurnal variaitons on precipitation seems quite large. To take a deeper insight on short-term variability of recipitation isotopes, including diurnal variability, the authors developed an isotope-incorporated land surface model coupled with the existed atmospheric isotope circulation model