Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica
The summer enhancement of diurnal tidal currents at the shelf break in the southern Weddell Sea is studied using velocity measurements from 29 moorings during the period 1968 to 2014. Kinetic energy associated with diurnal tidal frequencies is largest at the shelf break and decreases rapidly with di...
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ftdoajarticles:oai:doaj.org/article:a5cd89859fe74093b858be5678edd7d6 2023-05-15T13:46:49+02:00 Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica S. Semper E. Darelius 2017-01-01T00:00:00Z https://doi.org/10.5194/os-13-77-2017 https://doaj.org/article/a5cd89859fe74093b858be5678edd7d6 EN eng Copernicus Publications http://www.ocean-sci.net/13/77/2017/os-13-77-2017.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-13-77-2017 https://doaj.org/article/a5cd89859fe74093b858be5678edd7d6 Ocean Science, Vol 13, Iss 1, Pp 77-93 (2017) Geography. Anthropology. Recreation G Environmental sciences GE1-350 article 2017 ftdoajarticles https://doi.org/10.5194/os-13-77-2017 2022-12-30T22:42:20Z The summer enhancement of diurnal tidal currents at the shelf break in the southern Weddell Sea is studied using velocity measurements from 29 moorings during the period 1968 to 2014. Kinetic energy associated with diurnal tidal frequencies is largest at the shelf break and decreases rapidly with distance from it. The diurnal tidal energy increases from austral winter to summer by, on average, 50 %. The austral summer enhancement is observed in all deployments. The observations are compared to results from an idealised numerical solution of the properties of coastal trapped waves (CTWs) for a given bathymetry, stratification and an along-slope current. The frequency at which the dispersion curve for mode 1 CTWs displays a maximum (i.e. where the group velocity is zero and resonance is possible) is found within or near the diurnal frequency band, and it is sensitive to the stratification in the upper part of the water column and to the background current. The maximum of the dispersion curve is shifted towards higher frequencies, above the diurnal band, for weak stratification and a strong background current (i.e. austral winter-like conditions) and towards lower frequencies for strong upper-layer stratification and a weak background current (austral summer). The seasonal evolution of hydrography and currents in the region is inferred from available mooring data and conductivity–temperature–depth profiles. Near-resonance of diurnal tidal CTWs during austral summer can explain the observed seasonality in tidal currents. Article in Journal/Newspaper Antarc* Antarctica Weddell Sea Directory of Open Access Journals: DOAJ Articles Weddell Sea Austral Weddell Ocean Science 13 1 77 93 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
spellingShingle |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 S. Semper E. Darelius Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica |
topic_facet |
Geography. Anthropology. Recreation G Environmental sciences GE1-350 |
description |
The summer enhancement of diurnal tidal currents at the shelf break in the southern Weddell Sea is studied using velocity measurements from 29 moorings during the period 1968 to 2014. Kinetic energy associated with diurnal tidal frequencies is largest at the shelf break and decreases rapidly with distance from it. The diurnal tidal energy increases from austral winter to summer by, on average, 50 %. The austral summer enhancement is observed in all deployments. The observations are compared to results from an idealised numerical solution of the properties of coastal trapped waves (CTWs) for a given bathymetry, stratification and an along-slope current. The frequency at which the dispersion curve for mode 1 CTWs displays a maximum (i.e. where the group velocity is zero and resonance is possible) is found within or near the diurnal frequency band, and it is sensitive to the stratification in the upper part of the water column and to the background current. The maximum of the dispersion curve is shifted towards higher frequencies, above the diurnal band, for weak stratification and a strong background current (i.e. austral winter-like conditions) and towards lower frequencies for strong upper-layer stratification and a weak background current (austral summer). The seasonal evolution of hydrography and currents in the region is inferred from available mooring data and conductivity–temperature–depth profiles. Near-resonance of diurnal tidal CTWs during austral summer can explain the observed seasonality in tidal currents. |
format |
Article in Journal/Newspaper |
author |
S. Semper E. Darelius |
author_facet |
S. Semper E. Darelius |
author_sort |
S. Semper |
title |
Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica |
title_short |
Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica |
title_full |
Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica |
title_fullStr |
Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica |
title_full_unstemmed |
Seasonal resonance of diurnal coastal trapped waves in the southern Weddell Sea, Antarctica |
title_sort |
seasonal resonance of diurnal coastal trapped waves in the southern weddell sea, antarctica |
publisher |
Copernicus Publications |
publishDate |
2017 |
url |
https://doi.org/10.5194/os-13-77-2017 https://doaj.org/article/a5cd89859fe74093b858be5678edd7d6 |
geographic |
Weddell Sea Austral Weddell |
geographic_facet |
Weddell Sea Austral Weddell |
genre |
Antarc* Antarctica Weddell Sea |
genre_facet |
Antarc* Antarctica Weddell Sea |
op_source |
Ocean Science, Vol 13, Iss 1, Pp 77-93 (2017) |
op_relation |
http://www.ocean-sci.net/13/77/2017/os-13-77-2017.pdf https://doaj.org/toc/1812-0784 https://doaj.org/toc/1812-0792 1812-0784 1812-0792 doi:10.5194/os-13-77-2017 https://doaj.org/article/a5cd89859fe74093b858be5678edd7d6 |
op_doi |
https://doi.org/10.5194/os-13-77-2017 |
container_title |
Ocean Science |
container_volume |
13 |
container_issue |
1 |
container_start_page |
77 |
op_container_end_page |
93 |
_version_ |
1766245252948033536 |