Controlled experiments on the diffusion rate of stable isotopes of water in artificial firn
2007 (English)In: Journal of Glaciology, ISSN 0022-1430, Vol. 53, no 183, 537-546 p.Article in journal (Refereed) Published
We studied the diffusion rate of stable isotopes of water ice in a controlled laboratory experiment, where isotopically different layers of fabricated firn were stacked. This experiment was done in order to study the diffusion rate between the isotopically different layers and to further compare the measured results with forward calculated diffusion rates of the fabricated firn stack, using three different analytical and numerical methods. The layers varied in thickness within the stack and the studied period includes variations in firn temperatures. We sampled the firn-stack on five different dates along the totally 144-d long experiment. We get a quantitatively good match between the calculated and the measured diffusion rates, with a RMS similarity of 67-80 % in the depth averaged diffusion rates. Despite the good average match, we find some qualitative discrepancy between our calculations and our measurements. The calculated diffusion rates predict more than 5 % faster isotopic decay of thinner layers and 13 % slower decay of thicker layers in the experiment than measurements show. This We speculate that grain size and grain fabric may influence the tortuosity the firn pack, and that the current generalization of tortuosity being a function of firn density as the only free parameter is an oversimplification
Place, publisher, year, edition, pages
2007. Vol. 53, no 183, 537-546 p.
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-11763DOI: 10.3189/002214307784409379ISI: 000252626400002OAI: oai:DiVA.org:uu-11763DiVA: diva2:39532