Integration of global precipitation stable isotope data

Abstract. Precipitation plays a crucial role in the hydrological cycle and is vital for water resources management, climate change research, and ecosystem conservation. Precipitation stable isotopes serve as the "fingerprints" of precipitation, which can clearly trace the formation, transport, and subsequent processes of precipitation. However, due to the scarcity of precipitation stable isotope data, we face challenges of temporal discontinuity and spatial heterogeneity when studying it at large to medium scales. Therefore, we compiled precipitation hydrogen and oxygen stable isotope data (δ¹⁸O and δ²H) from 2059 global sites spanning from 1961 to 2023, totaling 141,624 records. Our study indicates significant variations of global precipitation stable isotopes both spatially and temporally. Spatially, the isotopic composition of precipitation in different regions varies significantly due to factors such as geographical location, underlying surface conditions, and atmospheric circulation. Temporally, δ¹⁸O and δ²H show decreasing trends, while d-excess shows an increasing trend, with the impact of global temperature rise being very apparent. This precipitation stable isotope dataset provides robust support for our understanding of global precipitation changes and climate change. Through further investigation of precipitation stable isotope data, we hope to uncover more mechanisms and influencing factors of precipitation processes, providing a more accurate basis for the assessment and prediction of climate and water resource changes.