"This award is funded under the American Recovery and Reinvestment Act of 2009 (Public Law 111-5)." This award will fund acquisition of a liquid oxygen isotope analyzer. The device is a reasonably new instrument relying on cavity ringdown spectroscopy. Precision specifications for this instrument are published at 0.1 permil and 0.3 permil for oxygen and deuterium isotope ratios, respectively. The instrument will be housed in the Water Science Laboratory at OSU. A technician will oversee the use, training and maintenance for the instrument. User fees will be used to pay for supplies and maintenance (but kept as low as possible). The PIs will evaluate requests from theses projects and adjust costs as low as possible. The liquid water isotope analyzer (LWIA) will be used to source apportion water (groundwater vs. overland flow) to understand carbon flow in natural and managed watersheds, to measure oxygen and hydrogen isotope ratios of surface meltwater in order to gain an understanding of storage, sources, residence time and transport of water associated with glaciers, to understand precipitation, freezing, glacier dynamics and meltwater contributions to the hydrogeologic cycle over longer and higher resolution timescales (seasonal and interannaul), to calculate paleotemperatures using coral skeletal oxygen ratios which vary when deposited based on ambient temperature, and overall to employ isotopic analysis to better understand climate change and biogeochemistry. The PIs have a history of producing graduates from women and minority sectors. PIs will conduct research with considerable societal relevance (watershed management impacts, climate forcings, hydrogeologic cycles). Undergraduates will be incorporated into research projects.