| Description |
Changing climate influences water resources by altering precipitation amount, intensity, and seasonal timing, which impact water availability in terrestrial systems. Stable isotope ratios of hydrogen ( 2H 1H) and oxygen ( 18O 16O) in precipitation exhibit spatial and temporal variability that arises from variation in hydroclimatic processes, and thus trace hydroclimatic processes and change across temporal and spatial scales. In this dissertation I describe the structure and management of the open access Waterisotopes database, and use either a single or the compiled global precipitation isotope ratio dataset from the database to address questions of hydroclimatic processes and change. From analysis of a single event scale precipitation isotope dataset, I examine the present state of the Arctic hydrologic cycle in eastern Siberia, finding a potential signal of contribution of Arctic vapor during the cold season. Using the compiled, processed dataset, I identify a timeseries length limitation of approximately 5 years for calculating robust local meteoric water lines, though this guideline shifts depending on how the meteoric water line will be used. I link the spatial variability of the global dataset of meteoric water line to processes including subcloud evaporation, continental recycling, and mixed phase cloud processes, and use these process links to benchmark global climate models. My results suggest that models can improve subcloud evaporation and continental recycling processes. Finally, I used the compiled dataset to examine global multidecadal oxygen isotope change. The results suggest that precipitation isotopes record nonlocal dynamic changes, with differing hydroclimatic controls over land and ocean. This result contrasts with the isotope enabled global climate model response to climate change, which primarily reflects local changes to the water balance. The infrastructure and isotope-atmospheric process relationships developed in this dissertation have implications for interpretation of hydroclimatic processes and change, including model evaluation and interpretation of paleoclimate proxies. |
