Isotope tracers in the water cycle


Water isotopes are the foundation for understanding the H and O isotopic composition of plant and animal tissues, supporting applications in areas such as ecophysiology, biogeochemistry, and migration ecology. Moreover water isotopes can record the impact of humans and the biosphere on the water cycle. The isotopic compositions of environmental waters have been extensively documented through global and national monitoring programs and thousands of published studies and reports. Long-standing theory relates variation of water isotope ratios to water cycle processes. Of primary importance is the transfer of water between liquid or solid and vapor phases during residence within or transport through a system (e.g., the atmosphere, streams, or plant tissues), which preferentially partitions the heavier isotopes 2H and 18O into the liquid and/or solid phases. In recent years, analysis of regional to continental scale datasets for precipitation and surface water isotope ratios using statistical and process-based models has demonstrated the potential to extract useful data on hydrological systems. The extension of this work to probe ecohydrological phenomena and the integration of stable isotope monitoring data with other environmental geodata has been limited, however.

This project will support a postdoc to advance spatial analysis and modeling methods for extracting ecohydrological and hydrological information from spatially distributed monitoring networks and investigate the strengths and limitations of water isotope tracers across a wide range of spatial scales. Strong foundations for this work include published data and formal and informal monitoring networks recording water isotopic composition. In addition, atmospheric water vapor isotope ratio data from satellites and several new networks of ground-based instruments, including new CRDS analyzers deployed by the project and ITCE faculty, are available to support this work.

The work should provide an enhaced basis for using network-based water isotope ratio data in support of ecological, hydrological, or hydroclimatological research. Potential fundamental research questions include:

  • Can isotopic monitoring data documenting the inputs (precipitation), outputs (streamflow) and boundary conditions (atmospheric vapor) be used to extract information on the spatial and temporal variability of catchment-scale partitioning of rainfall into runoff, evaporation, and storage?
  • Over what range of catchment scales and conditions can this be done, and to what degree does the use of model-derived data products to represent one or more isotopic parameters at large spatial scales compromise the application?
  • Can factors such as climate, land management (cropping, irrigation, urbanization), physiography, and ecosystem productivity (NDVI) be correlated with isotopic indicators for regional variation catchment water fluxes, and to what degree are these relationships static over larger (continental) scales?

Affiliated faculty

Bowen, Brooks, Dawson, Kendall, McDonnell, Pataki,Noone


ITCE News!

New Instructional Video Module on Biogeography and Isotope Fractionation in C3 & C4 plants with Christopher Still! Check out all of the videos at the bottom of the 'Summer Courses' tab!


New Publications - Two new papers by SPATIAL alum Sean Brennan involving salmon migration (here) and using dendritic network models to improve Strontium isoscapes (here)!


New Blog Post - Former SPATIAL student Katie Wedemeyer-Strombel discusses her experience as a SPATIAL student last summer! (Check it out here!)


Awards - Former ITCE post-doc Jennifer Cotton has received an NSF Macrosystems Biology Grant. Congratulations, Jen! (Check out the NEON press release here!)

New Publications - Former SPATIAL student Chabi Djagoun's work on carbon isotope niches in herbivores in a west African savannah is now available in Mammalian Biology - Free download until Nov 7th! (Check it out here)


New Publications - Former SPATIAL student Giovanny Mosquera in two new publications involving high elevation tropical ecosystems (Hydrological Processes and Hydrology and Earth System Sciences)


Awards - Congratulations to Jim Ehleringer for receiving the prestigious Rosenblatt Prize for Excellenc! (Read more here.)


Presentations - Several SPATIAL & IsoCamp instructors and past students represented at the 10th annual (ISOECOL meeting in Tokyo!) last week.

Archived ITCE News


IsoMAP: WebGIS for Isotopes

IsoMAP is a dynamic, online workspace for spatial analysis, modeling and prediction of stable isotope ratio variation in the natural environment. The initial realease of the IsoMAP gateway is now live and supports precipitation isotope ratio modeling. Visit IsoMAP to learn more or to start making isoscapes today!