On the propagation of acoustic-gravity waves under elastic ice sheets
The propagation of wave disturbances in water of varying depth bounded above by ice sheets is discussed, accounting for gravity, compressibility and elasticity effects. Considering the more realistic scenario of elastic ice sheets reveals a continuous spectrum of acoustic-gravity modes that propagat...
Published in: | Journal of Fluid Mechanics |
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Language: | English |
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2018
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Online Access: | https://doi.org/10.1017/jfm.2017.808 |
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ftncar:oai:drupal-site.org:articles_21226 2023-09-05T13:20:16+02:00 On the propagation of acoustic-gravity waves under elastic ice sheets Abdolali, Ali (author) Kadri, Usama (author) Parsons, Wade (author) Kirby, James T. (author) 2018-02-25 https://doi.org/10.1017/jfm.2017.808 en eng Journal of Fluid Mechanics--J. Fluid Mech.--0022-1120--1469-7645 articles:21226 ark:/85065/d7057jj9 doi:10.1017/jfm.2017.808 Copyright 2018 Cambridge University Press article Text 2018 ftncar https://doi.org/10.1017/jfm.2017.808 2023-08-14T18:48:15Z The propagation of wave disturbances in water of varying depth bounded above by ice sheets is discussed, accounting for gravity, compressibility and elasticity effects. Considering the more realistic scenario of elastic ice sheets reveals a continuous spectrum of acoustic-gravity modes that propagate even below the cutoff frequency of the rigid surface solution where surface (gravity) waves cannot exist. The balance between gravitational forces and oscillations in the ice sheet defines a new dimensionless quantity K-a. When the ice sheet is relatively thin and the prescribed frequency is relatively low (Ka << 1), the free-surface bottom-pressure solution is retrieved in full. However, thicker ice sheets or propagation of relatively higher frequency modes (Ka >> 1) alter the solution fundamentally, which is reflected in an amplified asymmetric signature and different characteristics of the eigenvalues, such that the bottom pressure is amplified when acoustic-gravity waves are transmitted to shallower waters. To analyse these scenarios, an analytical solution and a depth-integrated equation are derived for the cases of constant and varying depths, respectively. Together, these are capable of modelling realistic ocean geometries and an inhomogeneous distribution of ice sheets. National Science Foundation (NSF): CMMI-1537232 Article in Journal/Newspaper Ice Sheet OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) Journal of Fluid Mechanics 837 640 656 |
institution |
Open Polar |
collection |
OpenSky (NCAR/UCAR - National Center for Atmospheric Research/University Corporation for Atmospheric Research) |
op_collection_id |
ftncar |
language |
English |
description |
The propagation of wave disturbances in water of varying depth bounded above by ice sheets is discussed, accounting for gravity, compressibility and elasticity effects. Considering the more realistic scenario of elastic ice sheets reveals a continuous spectrum of acoustic-gravity modes that propagate even below the cutoff frequency of the rigid surface solution where surface (gravity) waves cannot exist. The balance between gravitational forces and oscillations in the ice sheet defines a new dimensionless quantity K-a. When the ice sheet is relatively thin and the prescribed frequency is relatively low (Ka << 1), the free-surface bottom-pressure solution is retrieved in full. However, thicker ice sheets or propagation of relatively higher frequency modes (Ka >> 1) alter the solution fundamentally, which is reflected in an amplified asymmetric signature and different characteristics of the eigenvalues, such that the bottom pressure is amplified when acoustic-gravity waves are transmitted to shallower waters. To analyse these scenarios, an analytical solution and a depth-integrated equation are derived for the cases of constant and varying depths, respectively. Together, these are capable of modelling realistic ocean geometries and an inhomogeneous distribution of ice sheets. National Science Foundation (NSF): CMMI-1537232 |
author2 |
Abdolali, Ali (author) Kadri, Usama (author) Parsons, Wade (author) Kirby, James T. (author) |
format |
Article in Journal/Newspaper |
title |
On the propagation of acoustic-gravity waves under elastic ice sheets |
spellingShingle |
On the propagation of acoustic-gravity waves under elastic ice sheets |
title_short |
On the propagation of acoustic-gravity waves under elastic ice sheets |
title_full |
On the propagation of acoustic-gravity waves under elastic ice sheets |
title_fullStr |
On the propagation of acoustic-gravity waves under elastic ice sheets |
title_full_unstemmed |
On the propagation of acoustic-gravity waves under elastic ice sheets |
title_sort |
on the propagation of acoustic-gravity waves under elastic ice sheets |
publishDate |
2018 |
url |
https://doi.org/10.1017/jfm.2017.808 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
Journal of Fluid Mechanics--J. Fluid Mech.--0022-1120--1469-7645 articles:21226 ark:/85065/d7057jj9 doi:10.1017/jfm.2017.808 |
op_rights |
Copyright 2018 Cambridge University Press |
op_doi |
https://doi.org/10.1017/jfm.2017.808 |
container_title |
Journal of Fluid Mechanics |
container_volume |
837 |
container_start_page |
640 |
op_container_end_page |
656 |
_version_ |
1776200973294764032 |