An increasing number of scientists and disciplines around the world are benefitting from the application of stable water isotope techniques (2H and 18O), especially in ecohydrology. Stable isotope analysis of environmental waters in soil and the atmosphere can help to investigate water flow paths through the Earth’s critical zone. However, clear bottlenecks for the ubiquitous application of isotopic analysis are the relatively high-energy and specialized materials required to collect and extract water from soil materials. Could a simple and cost-effective desiccant-media based methods be sufficient for collection of soil and atmospheric water vapor for isotopic analysis?

In this study, we would like to test a novel technique for water vapor collection and extraction and compare this to a standard research-grade water extraction methods.

Against this background, the potential candidate would:

• Conduct water extractions for multiple water-absorbent medias across different soil types, atmospheric water vapor contents and time spans
• Sample pore water isotopes with different extraction methods
• Determine isotopic differences between different methods
• Analyze and interpret the isotope data

The student/s should be interested in conducting field and lab work and be familiar with statistical software, such as R or Python.

Dr. Natalie Orlowski, Tel. +49 (0)761 / 203-9283, natalie.orlowski@hydrology.uni-freiburg.de

Assist. Prof. Stephen Good, College of Agricultural Sciences, Biological & Ecological Engineering, Oregon State University, United States; stephen.good@oregonstate.edu

English

• Orlowski, N., Pratt, D. L. and McDonnell, J. J.: Intercomparison of soil pore water extraction methods for stable isotope analysis, Hydrol. Process., 30(19), 3434–3449, doi:10.1002/hyp.10870, 2016.
• Sprenger, M., Herbstritt, B. and Weiler, M.: Established methods and new opportunities for pore water stable isotope analysis, Hydrol. Process., 29(25), 5174–5192, doi:10.1002/hyp.10643, 2015.