Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements
Firn microstructure properties from six different sites in Greenland and Antarctica are investigated by means of X-ray microcomputer tomography. The optical effective radius is calculated from the specific surface area (SSA) and used as a measure of grain size. It is shown that the recently introduc...
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ftawi:oai:epic.awi.de:31503 2024-09-15T17:44:47+00:00 Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements Linow, Stefanie Hörhold, Maria Freitag, Johannes 2012 https://epic.awi.de/id/eprint/31503/ https://doi.org/10.3189/2012JoG11J256 https://hdl.handle.net/10013/epic.40394 unknown Linow, S. , Hörhold, M. and Freitag, J. orcid:0000-0003-2654-9440 (2012) Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements , Journal of Glaciology, 58 (212), pp. 1245-1252 . doi:10.3189/2012JoG11J256 <https://doi.org/10.3189/2012JoG11J256> , hdl:10013/epic.40394 EPIC3Journal of Glaciology, 58(212), pp. 1245-1252, ISSN: 00221430 Article isiRev 2012 ftawi https://doi.org/10.3189/2012JoG11J256 2024-06-24T04:06:16Z Firn microstructure properties from six different sites in Greenland and Antarctica are investigated by means of X-ray microcomputer tomography. The optical effective radius is calculated from the specific surface area (SSA) and used as a measure of grain size. It is shown that the recently introduced spherical approximation of firn grains using the effective radius R_eff is representative of grain size in the microwave frequency region. The measured profiles show the well-known increase of grain size with depth at all sites, where the increase is largest at near-surface depths. A large variability in grain size on the decimeter-to-centimeter scale as a result of different grain properties of single layers is superimposed on the overall trend at each site. A simple empirical parameterization of grain-size evolution is developed which allows the rapid grain growth in the uppermost layers of the firn to be predicted. The growth is driven by strong seasonal and diurnal temperature gradients. The model can be used to simulate grain-size profiles required by models of firn/microwave interaction (e.g. for retrieval of accumulation rates from satellite microwave sensors) in a more realistic fashion. Article in Journal/Newspaper Antarc* Antarctica Greenland Journal of Glaciology Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) Journal of Glaciology 58 212 1245 1252 |
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Alfred Wegener Institute for Polar- and Marine Research (AWI): ePIC (electronic Publication Information Center) |
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ftawi |
language |
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description |
Firn microstructure properties from six different sites in Greenland and Antarctica are investigated by means of X-ray microcomputer tomography. The optical effective radius is calculated from the specific surface area (SSA) and used as a measure of grain size. It is shown that the recently introduced spherical approximation of firn grains using the effective radius R_eff is representative of grain size in the microwave frequency region. The measured profiles show the well-known increase of grain size with depth at all sites, where the increase is largest at near-surface depths. A large variability in grain size on the decimeter-to-centimeter scale as a result of different grain properties of single layers is superimposed on the overall trend at each site. A simple empirical parameterization of grain-size evolution is developed which allows the rapid grain growth in the uppermost layers of the firn to be predicted. The growth is driven by strong seasonal and diurnal temperature gradients. The model can be used to simulate grain-size profiles required by models of firn/microwave interaction (e.g. for retrieval of accumulation rates from satellite microwave sensors) in a more realistic fashion. |
format |
Article in Journal/Newspaper |
author |
Linow, Stefanie Hörhold, Maria Freitag, Johannes |
spellingShingle |
Linow, Stefanie Hörhold, Maria Freitag, Johannes Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements |
author_facet |
Linow, Stefanie Hörhold, Maria Freitag, Johannes |
author_sort |
Linow, Stefanie |
title |
Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements |
title_short |
Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements |
title_full |
Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements |
title_fullStr |
Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements |
title_full_unstemmed |
Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements |
title_sort |
grain-size evolution of polar firn: a new empirical grain growth parameterization based on x-ray microcomputer tomography measurements |
publishDate |
2012 |
url |
https://epic.awi.de/id/eprint/31503/ https://doi.org/10.3189/2012JoG11J256 https://hdl.handle.net/10013/epic.40394 |
genre |
Antarc* Antarctica Greenland Journal of Glaciology |
genre_facet |
Antarc* Antarctica Greenland Journal of Glaciology |
op_source |
EPIC3Journal of Glaciology, 58(212), pp. 1245-1252, ISSN: 00221430 |
op_relation |
Linow, S. , Hörhold, M. and Freitag, J. orcid:0000-0003-2654-9440 (2012) Grain-size evolution of polar firn: a new empirical grain growth parameterization based on X-ray microcomputer tomography measurements , Journal of Glaciology, 58 (212), pp. 1245-1252 . doi:10.3189/2012JoG11J256 <https://doi.org/10.3189/2012JoG11J256> , hdl:10013/epic.40394 |
op_doi |
https://doi.org/10.3189/2012JoG11J256 |
container_title |
Journal of Glaciology |
container_volume |
58 |
container_issue |
212 |
container_start_page |
1245 |
op_container_end_page |
1252 |
_version_ |
1810492440231018496 |