Temporal trends of deuterium excess in global precipitation and their environmental controls under a changing climate

Sixty-three representative sites around the world were selected to analyze the long-term variability of deuterium excess (d-excess) and its association with air temperature and precipitation amount. The results from the Mann-Kendall test showed that d-excess tended to increase at two-thirds of the sites. We demonstrated from several perspectives that high temperatures and concentrated precipitation can counteract the correlation between d-excess and these two meteorological factors. Our findings suggested that d-excess was an indicator for climate change at sites controlled by a single factor; however, at sites affected by multiple factors its role was more complicated.