A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions
Ocean motions at frequencies of the internal wave band are generally associated with freely propagating waves that are supported by stable vertical stratification in density. Previous analyses of yearlong current observations from the Bay of Biscay showed that a finestructure of semidiurnal tidal an...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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Stockholm University Press
2022-10-01
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| Series: | Tellus: Series A, Dynamic Meteorology and Oceanography |
| Subjects: | |
| Online Access: | https://a.tellusjournals.se/articles/45 |
| _version_ | 1811313151964086272 |
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| author | Hans van Haren Leo Maas |
| author_facet | Hans van Haren Leo Maas |
| author_sort | Hans van Haren |
| collection | DOAJ |
| description | Ocean motions at frequencies of the internal wave band are generally associated with freely propagating waves that are supported by stable vertical stratification in density. Previous analyses of yearlong current observations from the Bay of Biscay showed that a finestructure of semidiurnal tidal and near-inertial higher harmonics fills the spectrum. Here, a simple model is presented of forced nondispersive motions with forward energy cascade. The model fits the spectral shape of higher harmonics well within statistical significance and shows that such interactions imply maximum wave steepness in a balance between forcing and turbulent mixing. The single fitting parameter takes a value of approximately one, at which the barotropic tidal flow speed equals the internal wave phase speed. We infer that the barotropic tide sets a non-linear limit to baroclinic current scales without generating non-linear higher harmonics directly. |
| first_indexed | 2024-04-13T10:48:54Z |
| format | Article |
| id | doaj.art-41256da5a09b4c0cbf25e98a25c000dd |
| institution | Directory Open Access Journal |
| issn | 1600-0870 |
| language | English |
| last_indexed | 2024-04-13T10:48:54Z |
| publishDate | 2022-10-01 |
| publisher | Stockholm University Press |
| record_format | Article |
| series | Tellus: Series A, Dynamic Meteorology and Oceanography |
| spelling | doaj.art-41256da5a09b4c0cbf25e98a25c000dd2022-12-22T02:49:43ZengStockholm University PressTellus: Series A, Dynamic Meteorology and Oceanography1600-08702022-10-0174110.16993/tellusa.453185A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear InteractionsHans van Haren0Leo Maas1Royal Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den BurgInstitute for Marine and Atmospheric Research (IMAU), University of Utrecht, P.O. Box 80011, 3508 TA UtrechtOcean motions at frequencies of the internal wave band are generally associated with freely propagating waves that are supported by stable vertical stratification in density. Previous analyses of yearlong current observations from the Bay of Biscay showed that a finestructure of semidiurnal tidal and near-inertial higher harmonics fills the spectrum. Here, a simple model is presented of forced nondispersive motions with forward energy cascade. The model fits the spectral shape of higher harmonics well within statistical significance and shows that such interactions imply maximum wave steepness in a balance between forcing and turbulent mixing. The single fitting parameter takes a value of approximately one, at which the barotropic tidal flow speed equals the internal wave phase speed. We infer that the barotropic tide sets a non-linear limit to baroclinic current scales without generating non-linear higher harmonics directly.https://a.tellusjournals.se/articles/45internal wave observationsbay of biscaynon-linear higher harmonicsadvection modelforward cascade |
| spellingShingle | Hans van Haren Leo Maas A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions Tellus: Series A, Dynamic Meteorology and Oceanography internal wave observations bay of biscay non-linear higher harmonics advection model forward cascade |
| title | A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions |
| title_full | A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions |
| title_fullStr | A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions |
| title_full_unstemmed | A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions |
| title_short | A Simple Model for an Internal Wave Spectrum Dominated by Non-Linear Interactions |
| title_sort | simple model for an internal wave spectrum dominated by non linear interactions |
| topic | internal wave observations bay of biscay non-linear higher harmonics advection model forward cascade |
| url | https://a.tellusjournals.se/articles/45 |
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