Developing an Automated Rainwater Sampler for Stable Isotope Analysis

Common stable isotopes in water (O-18 and H-2) serve as important tools for our understanding of long-term climate change, atmospheric water cycles, and water management. Recognizing the importance of precipitation within the water cycle, communities such as The Global Network of Isotopes in Precipitation (GNIP) have made efforts to identify variations in the isotopic composition of rain. Nevertheless, current precipitation data lack high temporal and spatial resolution due to expensive equipment and limited sites, necessitating alternative sampling methods to enhance data collection. Here we developed an inexpensive, autonomous rainwater sampler for stable isotope analysis at the Jack and Laura Dangermond Preserve, southern California. In contrast to traditional rain gauges, our sampler has been designed to reduce post-sampling fractionation, improving our ability to obtain accurate samples for stable isotope analysis. The sampler design can be readily adapted for other remote locations as well as the collection of unstable isotope (H-3) samples. Our improved design will enable the reliable rainwater collection at the Jack and Laura Dangermond Preserve, while providing an adaptable framework for future applications.

Faculty Mentor: Scott Jasechko

Project Mentor: Annette Hilton, Alison Rickard