Statistics of firn closure: a simulation study
Abstract The trapping of bubbles of air in polar ice has provided a unique record of past atmospheric composition. However, the interpretation of measured concentrations depends on the statistics of the trapping process. Measurements of trace atmospheric constituents whose concentrations are changin...
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Cambridge University Press (CUP)
1993
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Online Access: | http://dx.doi.org/10.1017/s0022143000015781 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015781 |
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crcambridgeupr:10.1017/s0022143000015781 2024-03-03T08:45:59+00:00 Statistics of firn closure: a simulation study Enting, I. G. 1993 http://dx.doi.org/10.1017/s0022143000015781 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015781 en eng Cambridge University Press (CUP) Journal of Glaciology volume 39, issue 131, page 133-142 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 1993 crcambridgeupr https://doi.org/10.1017/s0022143000015781 2024-02-08T08:37:11Z Abstract The trapping of bubbles of air in polar ice has provided a unique record of past atmospheric composition. However, the interpretation of measured concentrations depends on the statistics of the trapping process. Measurements of trace atmospheric constituents whose concentrations are changing steadily can be interpreted in terms of an “effective age” of the gas which differs from the age of the ice by a delay which corresponds to the mean trapping time. The statistics of bubble trapping can be modelled as a percolation model which is one of a class of models whose transitions are characterized by large critical fluctuations. These critical fluctuations cause an intrinsic sample-to-sample variability in the delay time and thus in the effective age. Monte Carlo simulations using a lattice model of the firn are presented, showing the effect of finite sample size on the age distribution of trapped gas. For samples containing more than about 10 3 –10 4 bubbles, the simulations indicate that the range of variability is small compared to the average duration of the trapping process. Article in Journal/Newspaper Journal of Glaciology Cambridge University Press Journal of Glaciology 39 131 133 142 |
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Open Polar |
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Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes Enting, I. G. Statistics of firn closure: a simulation study |
topic_facet |
Earth-Surface Processes |
description |
Abstract The trapping of bubbles of air in polar ice has provided a unique record of past atmospheric composition. However, the interpretation of measured concentrations depends on the statistics of the trapping process. Measurements of trace atmospheric constituents whose concentrations are changing steadily can be interpreted in terms of an “effective age” of the gas which differs from the age of the ice by a delay which corresponds to the mean trapping time. The statistics of bubble trapping can be modelled as a percolation model which is one of a class of models whose transitions are characterized by large critical fluctuations. These critical fluctuations cause an intrinsic sample-to-sample variability in the delay time and thus in the effective age. Monte Carlo simulations using a lattice model of the firn are presented, showing the effect of finite sample size on the age distribution of trapped gas. For samples containing more than about 10 3 –10 4 bubbles, the simulations indicate that the range of variability is small compared to the average duration of the trapping process. |
format |
Article in Journal/Newspaper |
author |
Enting, I. G. |
author_facet |
Enting, I. G. |
author_sort |
Enting, I. G. |
title |
Statistics of firn closure: a simulation study |
title_short |
Statistics of firn closure: a simulation study |
title_full |
Statistics of firn closure: a simulation study |
title_fullStr |
Statistics of firn closure: a simulation study |
title_full_unstemmed |
Statistics of firn closure: a simulation study |
title_sort |
statistics of firn closure: a simulation study |
publisher |
Cambridge University Press (CUP) |
publishDate |
1993 |
url |
http://dx.doi.org/10.1017/s0022143000015781 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143000015781 |
genre |
Journal of Glaciology |
genre_facet |
Journal of Glaciology |
op_source |
Journal of Glaciology volume 39, issue 131, page 133-142 ISSN 0022-1430 1727-5652 |
op_doi |
https://doi.org/10.1017/s0022143000015781 |
container_title |
Journal of Glaciology |
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39 |
container_issue |
131 |
container_start_page |
133 |
op_container_end_page |
142 |
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1792501744262971392 |