Global Precipitation d‐excess Dataset: A Critical Resource for Geographical Science Research

ABSTRACT As an indicator associated with dynamic non‐equilibrium fractionation and less affected by equilibrium condensation temperature, d‐excess holds unique application potential in geographical science research. Its continuous observation is crucial for understanding the water cycle, mechanisms of extreme precipitation, and evaluating atmospheric circulation models. However, the current scarcity of datasets with high spatiotemporal resolution has resulted in an unclear understanding of the spatiotemporal variation processes of d‐excess. Meanwhile, existing isotope general circulation models (iGCMs) suffer from issues such as high complexity and significant discrepancies in results, which hinder the advancement of in‐depth research. To this end, this study constructed d‐excess datasets with different time series based on 98,423 stable isotope records, in which the data is mainly concentrated in 1965–2021. The results show that the variations of d‐excess differ significantly across different climate types and time scales. This highlights the research gap where the dominant factors of d‐excess in the boundary layer remain unclear. The d‐excess dataset constructed lays a foundation for the application of iGCMs in geographical science fields such as boundary layer process exploration, and improvement of earth system models.