This article is a US Government work and is in the public domain in the USA.
Diffusion model validation and interpretation of stable isotopes in river and lake ice†
Article first published online: 21 FEB 2002
This article is US Government work and is in the public domain in the USA. Published in 2002 by John Wiley & Sons, Ltd.
Special Issue: Hydrology of Ice-Covered Rivers and Lakes
Volume 16, Issue 4, pages 851–872, March 2002
How to Cite
Ferrick, M. G., Calkins, D. J., Perron, N. M., Cragin, J. H. and Kendall, C. (2002), Diffusion model validation and interpretation of stable isotopes in river and lake ice. Hydrol. Process., 16: 851–872. doi: 10.1002/hyp.374
- Issue published online: 21 FEB 2002
- Article first published online: 21 FEB 2002
- Manuscript Revised: 10 FEB 2001
- Manuscript Received: 14 JUL 2000
- Secretary of the Army Research and Study Fellowship
- US Army Corps of Engineers
- stable isotopes;
- congelation ice;
- river ice;
- lake ice;
- diffusion model validation
The stable isotope stratigraphy of river- and lake-ice archives winter hydroclimatic conditions, and can potentially be used to identify changing water sources or to provide important insights into ice formation processes and growth rates. However, accurate interpretations rely on known isotopic fractionation during ice growth. A one-dimensional diffusion model of the liquid boundary layer adjacent to an advancing solid interface, originally developed to simulate solute rejection by growing crystals, has been used without verification to describe non-equilibrium fractionation during congelation ice growth. Results are not in agreement, suggesting the presence of important uncertainties. In this paper we seek validation of the diffusion model for this application using large-scale laboratory experiments with controlled freezing rates and frequent sampling. We obtained consistent, almost constant, isotopic boundary layer thicknesses over a representative range of ice growth rates on both quiescent and well-mixed water. With the 18O boundary layer thickness from the laboratory, the model successfully quantified reduced river-ice growth rates relative to those of a nearby lake. These results were more representative and easier to obtain than those of a conventional thermal ice-growth model. This diffusion model validation and boundary layer thickness determination provide a powerful tool for interpreting the stable isotope stratigraphy of floating ice. The laboratory experiment also replicated successive fractionation events in response to a freeze–thaw–refreeze cycle, providing a mechanism for apparent ice fractionation that exceeds equilibrium. Analysis of the composition of snow ice and frazil ice in river and lake cores indicated surprising similarities between these ice forms. Published in 2002 by John Wiley & Sons, Ltd.