Tracer transport in an isochronal ice-sheet model
ABSTRACT The full history of ice sheet and climate interactions is recorded in the vertical profiles of geochemical tracers in polar ice sheets. Numerical simulations of these archives promise great advances both in the interpretation of these reconstructions and the validation of the models themsel...
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Online Access: | http://dx.doi.org/10.1017/jog.2016.111 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001118 |
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crcambridgeupr:10.1017/jog.2016.111 2024-03-03T08:45:02+00:00 Tracer transport in an isochronal ice-sheet model BORN, ANDREAS 2016 http://dx.doi.org/10.1017/jog.2016.111 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001118 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by-nc-sa/4.0/ Journal of Glaciology volume 63, issue 237, page 22-38 ISSN 0022-1430 1727-5652 Earth-Surface Processes journal-article 2016 crcambridgeupr https://doi.org/10.1017/jog.2016.111 2024-02-08T08:31:45Z ABSTRACT The full history of ice sheet and climate interactions is recorded in the vertical profiles of geochemical tracers in polar ice sheets. Numerical simulations of these archives promise great advances both in the interpretation of these reconstructions and the validation of the models themselves. However, fundamental mathematical shortcomings of existing models subject tracers to spurious diffusion, thwarting straightforward solutions. Here, I propose a new vertical discretization for ice-sheet models that eliminates numerical diffusion entirely. Vertical motion through the model mesh is avoided by mimicking the real-world flow of ice as a thinning of underlying layers. A new layer is added to the surface at equidistant time intervals, isochronally, thus identifying each layer uniquely by its time of deposition and age. This new approach is implemented for a two-dimensional section through the summit of the Greenland ice sheet. The ability to directly compare simulations of vertical ice cores with reconstructed data is used to find optimal model parameters from a large ensemble of simulations. It is shown that because this tuning method uses information from all times included in the ice core, it constrains ice-sheet sensitivity more robustly than a realistic reproduction of the modern ice-sheet surface. Article in Journal/Newspaper Greenland ice core Ice Sheet Journal of Glaciology Cambridge University Press Greenland Journal of Glaciology 63 237 22 38 |
institution |
Open Polar |
collection |
Cambridge University Press |
op_collection_id |
crcambridgeupr |
language |
English |
topic |
Earth-Surface Processes |
spellingShingle |
Earth-Surface Processes BORN, ANDREAS Tracer transport in an isochronal ice-sheet model |
topic_facet |
Earth-Surface Processes |
description |
ABSTRACT The full history of ice sheet and climate interactions is recorded in the vertical profiles of geochemical tracers in polar ice sheets. Numerical simulations of these archives promise great advances both in the interpretation of these reconstructions and the validation of the models themselves. However, fundamental mathematical shortcomings of existing models subject tracers to spurious diffusion, thwarting straightforward solutions. Here, I propose a new vertical discretization for ice-sheet models that eliminates numerical diffusion entirely. Vertical motion through the model mesh is avoided by mimicking the real-world flow of ice as a thinning of underlying layers. A new layer is added to the surface at equidistant time intervals, isochronally, thus identifying each layer uniquely by its time of deposition and age. This new approach is implemented for a two-dimensional section through the summit of the Greenland ice sheet. The ability to directly compare simulations of vertical ice cores with reconstructed data is used to find optimal model parameters from a large ensemble of simulations. It is shown that because this tuning method uses information from all times included in the ice core, it constrains ice-sheet sensitivity more robustly than a realistic reproduction of the modern ice-sheet surface. |
format |
Article in Journal/Newspaper |
author |
BORN, ANDREAS |
author_facet |
BORN, ANDREAS |
author_sort |
BORN, ANDREAS |
title |
Tracer transport in an isochronal ice-sheet model |
title_short |
Tracer transport in an isochronal ice-sheet model |
title_full |
Tracer transport in an isochronal ice-sheet model |
title_fullStr |
Tracer transport in an isochronal ice-sheet model |
title_full_unstemmed |
Tracer transport in an isochronal ice-sheet model |
title_sort |
tracer transport in an isochronal ice-sheet model |
publisher |
Cambridge University Press (CUP) |
publishDate |
2016 |
url |
http://dx.doi.org/10.1017/jog.2016.111 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0022143016001118 |
geographic |
Greenland |
geographic_facet |
Greenland |
genre |
Greenland ice core Ice Sheet Journal of Glaciology |
genre_facet |
Greenland ice core Ice Sheet Journal of Glaciology |
op_source |
Journal of Glaciology volume 63, issue 237, page 22-38 ISSN 0022-1430 1727-5652 |
op_rights |
http://creativecommons.org/licenses/by-nc-sa/4.0/ |
op_doi |
https://doi.org/10.1017/jog.2016.111 |
container_title |
Journal of Glaciology |
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63 |
container_issue |
237 |
container_start_page |
22 |
op_container_end_page |
38 |
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1792500546218754048 |