Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica
The ice front region of Ronne Ice Shelf lies near the critical latitude of the semidiurnal M2 tide, the principal tidal constituent in the southern Weddell Sea. Here the Coriolis frequency almost equals the M2 tidal frequency, resulting in a strong dependence of the M2 tidal currents on depth and st...
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American Geophysical Union
2006
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Online Access: | https://hdl.handle.net/1956/1163 https://doi.org/10.1029/2005jc003062 |
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ftunivbergen:oai:bora.uib.no:1956/1163 2023-05-15T14:07:50+02:00 Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica Makinson, Keith Schröder, Michael Østerhus, Svein 2006-03-30 1749063 bytes application/pdf https://hdl.handle.net/1956/1163 https://doi.org/10.1029/2005jc003062 eng eng American Geophysical Union urn:issn:0148-0227 https://hdl.handle.net/1956/1163 https://doi.org/10.1029/2005jc003062 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Journal article 2006 ftunivbergen https://doi.org/10.1029/2005jc003062 2023-03-14T17:44:33Z The ice front region of Ronne Ice Shelf lies near the critical latitude of the semidiurnal M2 tide, the principal tidal constituent in the southern Weddell Sea. Here the Coriolis frequency almost equals the M2 tidal frequency, resulting in a strong dependence of the M2 tidal currents on depth and stratification and a boundary layer that can occupy the entire water column. Using data from four long-term moorings along Ronne Ice Front, we confirm the presence of strongly depth-dependent semidiurnal tidal currents and their sensitivity to changes in stratification. The time series show dramatic seasonal changes in tidal current profiles and significant interannual variability. During periods of stratification, the amplitude of the semidiurnal tides in the mid–water column shows a twofold increase and, despite being several kilometers offshore from the ice front, the tidal currents clearly show a second boundary layer originating from the adjacent ice shelf base. Together, these two boundary layers occupy most of the water column, up to 600 m deep, until intense sea ice formation and the production of High-Salinity Shelf Water erodes the vertical stratification. During winter when homogeneous conditions prevail, a single bottom boundary layer occupies the entire water column at some locations. This strong seasonality and sensitivity of the M2 tidal current to stratification highlights the difficulties of interpreting current data from short-term moorings while demonstrating that it is the best indicator for characterizing changes in stratification after direct observations of density variations. Article in Journal/Newspaper Antarc* Antarctica Ice Shelf Ronne Ice Shelf Sea ice Weddell Sea University of Bergen: Bergen Open Research Archive (BORA-UiB) Ronne Ice Front ENVELOPE(-55.000,-55.000,-76.000,-76.000) Ronne Ice Shelf ENVELOPE(-61.000,-61.000,-78.500,-78.500) Weddell Weddell Sea Journal of Geophysical Research 111 C3 |
institution |
Open Polar |
collection |
University of Bergen: Bergen Open Research Archive (BORA-UiB) |
op_collection_id |
ftunivbergen |
language |
English |
topic |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 |
spellingShingle |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 Makinson, Keith Schröder, Michael Østerhus, Svein Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica |
topic_facet |
VDP::Matematikk og Naturvitenskap: 400::Geofag: 450::Oseanografi: 452 VDP::Matematikk og Naturvitenskap: 400::Geofag: 450 |
description |
The ice front region of Ronne Ice Shelf lies near the critical latitude of the semidiurnal M2 tide, the principal tidal constituent in the southern Weddell Sea. Here the Coriolis frequency almost equals the M2 tidal frequency, resulting in a strong dependence of the M2 tidal currents on depth and stratification and a boundary layer that can occupy the entire water column. Using data from four long-term moorings along Ronne Ice Front, we confirm the presence of strongly depth-dependent semidiurnal tidal currents and their sensitivity to changes in stratification. The time series show dramatic seasonal changes in tidal current profiles and significant interannual variability. During periods of stratification, the amplitude of the semidiurnal tides in the mid–water column shows a twofold increase and, despite being several kilometers offshore from the ice front, the tidal currents clearly show a second boundary layer originating from the adjacent ice shelf base. Together, these two boundary layers occupy most of the water column, up to 600 m deep, until intense sea ice formation and the production of High-Salinity Shelf Water erodes the vertical stratification. During winter when homogeneous conditions prevail, a single bottom boundary layer occupies the entire water column at some locations. This strong seasonality and sensitivity of the M2 tidal current to stratification highlights the difficulties of interpreting current data from short-term moorings while demonstrating that it is the best indicator for characterizing changes in stratification after direct observations of density variations. |
format |
Article in Journal/Newspaper |
author |
Makinson, Keith Schröder, Michael Østerhus, Svein |
author_facet |
Makinson, Keith Schröder, Michael Østerhus, Svein |
author_sort |
Makinson, Keith |
title |
Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica |
title_short |
Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica |
title_full |
Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica |
title_fullStr |
Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica |
title_full_unstemmed |
Effect of critical latitude and seasonal stratification on tidal current profiles along Ronne Ice Front, Antarctica |
title_sort |
effect of critical latitude and seasonal stratification on tidal current profiles along ronne ice front, antarctica |
publisher |
American Geophysical Union |
publishDate |
2006 |
url |
https://hdl.handle.net/1956/1163 https://doi.org/10.1029/2005jc003062 |
long_lat |
ENVELOPE(-55.000,-55.000,-76.000,-76.000) ENVELOPE(-61.000,-61.000,-78.500,-78.500) |
geographic |
Ronne Ice Front Ronne Ice Shelf Weddell Weddell Sea |
geographic_facet |
Ronne Ice Front Ronne Ice Shelf Weddell Weddell Sea |
genre |
Antarc* Antarctica Ice Shelf Ronne Ice Shelf Sea ice Weddell Sea |
genre_facet |
Antarc* Antarctica Ice Shelf Ronne Ice Shelf Sea ice Weddell Sea |
op_relation |
urn:issn:0148-0227 https://hdl.handle.net/1956/1163 https://doi.org/10.1029/2005jc003062 |
op_doi |
https://doi.org/10.1029/2005jc003062 |
container_title |
Journal of Geophysical Research |
container_volume |
111 |
container_issue |
C3 |
_version_ |
1766279871938428928 |