Constraints on the δ<sup>2</sup>H diffusion rate in firn from field measurements at Summit, Greenland
We performed detailed <sup>2</sup>H isotope diffusion measurements in the upper 3 m of firn at Summit, Greenland. Using a small snow gun, a thin snow layer was formed from <sup>2</sup>H-enriched water over a 6 × 6 m<sup>2</sup> area. We followed the diffusion proc...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2015-05-01
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| Series: | The Cryosphere |
| Online Access: | http://www.the-cryosphere.net/9/1089/2015/tc-9-1089-2015.pdf |
| Summary: | We performed detailed <sup>2</sup>H isotope diffusion measurements in the upper
3 m of firn at Summit, Greenland. Using a small snow gun, a thin snow
layer was formed from <sup>2</sup>H-enriched water over a 6 × 6 m<sup>2</sup> area. We
followed the diffusion process, quantified as the increase of the δ<sup>2</sup>H
diffusion length, over a 4-year period, by retrieving the layer
once per year by drilling a firn core and slicing it into 1 cm layers and
measuring the δ<sup>2</sup>H signal of these layers.
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We compared our experimental findings to calculations based on the model by
Johnsen et al. (2000) and found substantial differences. The
diffusion length in our experiments increased much less over the years than
in the model. We discuss the possible causes for this discrepancy and
conclude that several aspects of the diffusion process in firn are still
poorly constrained, in particular the tortuosity. |
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| ISSN: | 1994-0416 1994-0424 |