Normal modes of an ice sheet
A linearized perturbation about the Vialov-Nye fixed-span solution for a steady-state ice sheet yields a Sturm-Liouville problem. The numerical eigenvalue problem is solved and the resulting normal modes are used to compute Green's and influence functions for perturbations to the accumulation r...
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Cambridge University Press
1997
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ftnerc:oai:nora.nerc.ac.uk:514487 2023-05-15T16:39:47+02:00 Normal modes of an ice sheet Hindmarsh, Richard C.A. 1997-03 http://nora.nerc.ac.uk/id/eprint/514487/ https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/normal-modes-of-an-ice-sheet/82DA8DC64728CA80AED45CC2535F62AD unknown Cambridge University Press Hindmarsh, Richard C.A. orcid:0000-0003-1633-2416 . 1997 Normal modes of an ice sheet. Journal of Fluid Mechanics, 335 (1). 393-413. https://doi.org/10.1017/S0022112097001948 <https://doi.org/10.1017/S0022112097001948> Publication - Article PeerReviewed 1997 ftnerc https://doi.org/10.1017/S0022112097001948 2023-02-04T19:43:33Z A linearized perturbation about the Vialov-Nye fixed-span solution for a steady-state ice sheet yields a Sturm-Liouville problem. The numerical eigenvalue problem is solved and the resulting normal modes are used to compute Green's and influence functions for perturbations to the accumulation rate, the rate factor and for long-wavelength basal topography. The eigenvalue for the slowest mode is approximately the same as that predicted by the zero-dimensional theory. It is found that the sensitivity of the steady profile to accumulation is greatest in the central area of the ice sheet, while the sensitivity to rate factor is greatest near the margin. The antisymmetric perturbation provides information about the relaxation time for divide motion and spatial variation in the sensitivity of divide deviation from the ice-sheet centre to accumulation rate variations. The use of the method for model initialization is considered. Forcing deviations of 30% give relative errors in the perturbation of about 10%. Article in Journal/Newspaper Ice Sheet Natural Environment Research Council: NERC Open Research Archive Sturm ENVELOPE(162.967,162.967,-71.050,-71.050) |
institution |
Open Polar |
collection |
Natural Environment Research Council: NERC Open Research Archive |
op_collection_id |
ftnerc |
language |
unknown |
description |
A linearized perturbation about the Vialov-Nye fixed-span solution for a steady-state ice sheet yields a Sturm-Liouville problem. The numerical eigenvalue problem is solved and the resulting normal modes are used to compute Green's and influence functions for perturbations to the accumulation rate, the rate factor and for long-wavelength basal topography. The eigenvalue for the slowest mode is approximately the same as that predicted by the zero-dimensional theory. It is found that the sensitivity of the steady profile to accumulation is greatest in the central area of the ice sheet, while the sensitivity to rate factor is greatest near the margin. The antisymmetric perturbation provides information about the relaxation time for divide motion and spatial variation in the sensitivity of divide deviation from the ice-sheet centre to accumulation rate variations. The use of the method for model initialization is considered. Forcing deviations of 30% give relative errors in the perturbation of about 10%. |
format |
Article in Journal/Newspaper |
author |
Hindmarsh, Richard C.A. |
spellingShingle |
Hindmarsh, Richard C.A. Normal modes of an ice sheet |
author_facet |
Hindmarsh, Richard C.A. |
author_sort |
Hindmarsh, Richard C.A. |
title |
Normal modes of an ice sheet |
title_short |
Normal modes of an ice sheet |
title_full |
Normal modes of an ice sheet |
title_fullStr |
Normal modes of an ice sheet |
title_full_unstemmed |
Normal modes of an ice sheet |
title_sort |
normal modes of an ice sheet |
publisher |
Cambridge University Press |
publishDate |
1997 |
url |
http://nora.nerc.ac.uk/id/eprint/514487/ https://www.cambridge.org/core/journals/journal-of-fluid-mechanics/article/normal-modes-of-an-ice-sheet/82DA8DC64728CA80AED45CC2535F62AD |
long_lat |
ENVELOPE(162.967,162.967,-71.050,-71.050) |
geographic |
Sturm |
geographic_facet |
Sturm |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
Hindmarsh, Richard C.A. orcid:0000-0003-1633-2416 . 1997 Normal modes of an ice sheet. Journal of Fluid Mechanics, 335 (1). 393-413. https://doi.org/10.1017/S0022112097001948 <https://doi.org/10.1017/S0022112097001948> |
op_doi |
https://doi.org/10.1017/S0022112097001948 |
_version_ |
1766030112827899904 |