Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements
The mean dynamic topography (MDT) of the ocean is closely related to the mean surface circulation. The objective of this thesis is to produce estimates of the MDT for the North Atlantic using newly available data from ocean and gravity observing systems, to evaluate these new estimates and so improv...
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ftdalhouse:oai:DalSpace.library.dal.ca:10222/14866 2024-06-02T08:11:14+00:00 Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements Higginson, Simon Department of Oceanography Doctor of Philosophy Professor Philip Woodworth Dr Dan Kelley Dr Youyu Lu Dr Jianliang Huang Dr Markus Kienast Dr Keith Thompson Not Applicable 2012-05-23T14:17:50Z http://hdl.handle.net/10222/14866 en eng http://hdl.handle.net/10222/14866 Ocean circulation North Atlantic Mean dynamic topography 2012 ftdalhouse 2024-05-06T11:40:25Z The mean dynamic topography (MDT) of the ocean is closely related to the mean surface circulation. The objective of this thesis is to produce estimates of the MDT for the North Atlantic using newly available data from ocean and gravity observing systems, to evaluate these new estimates and so improve our understanding of the circulation. Oceanographic estimates of the MDT are based on the mean temperature and salinity (TS) fields of the ocean. These are typically averages from sparse observations collected over many decades. The ocean is a non-stationary system so it is more appropriate to define the mean for shorter, specific periods. Whilst the Argo observing system has increased the frequency and resolution of in situ oceanographic measurements, high frequency (eddy) variability remains. A new technique is described for removing this variability using satellite altimeter measurements of the sea surface height. A new TS mean is produced, relating to the period from 2000 to 2007, and this is used to map a new oceanographic estimate of the MDT using an ocean circulation model. New geodetic estimates of the MDT are produced using geoid models that incorporate gravity measurements from the ongoing GRACE and GOCE satellite missions. These are compared with the new oceanographic estimate and validated against independent observations such as drifter speeds. The geodetic method produces realistic estimates of the mean surface circulation, thereby realizing the long time dream of oceanographers to observe the ocean circulation from space. The new oceanographic estimates are not as accurate, but the new TS mean contributes to improvements in the performance of ocean models, a necessary step in understanding and predicting the oceans. Coastal tide gauges can provide an accurate estimate of the alongshore tilt of the coastal MDT and this has been used to evaluate the above estimates. Temporal variability of the tilt along the coast of the South Atlantic Bight is used, with statistical methods and an ocean circulation ... Other/Unknown Material North Atlantic Dalhousie University: DalSpace Institutional Repository |
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Open Polar |
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Dalhousie University: DalSpace Institutional Repository |
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ftdalhouse |
language |
English |
topic |
Ocean circulation North Atlantic Mean dynamic topography |
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Ocean circulation North Atlantic Mean dynamic topography Higginson, Simon Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements |
topic_facet |
Ocean circulation North Atlantic Mean dynamic topography |
description |
The mean dynamic topography (MDT) of the ocean is closely related to the mean surface circulation. The objective of this thesis is to produce estimates of the MDT for the North Atlantic using newly available data from ocean and gravity observing systems, to evaluate these new estimates and so improve our understanding of the circulation. Oceanographic estimates of the MDT are based on the mean temperature and salinity (TS) fields of the ocean. These are typically averages from sparse observations collected over many decades. The ocean is a non-stationary system so it is more appropriate to define the mean for shorter, specific periods. Whilst the Argo observing system has increased the frequency and resolution of in situ oceanographic measurements, high frequency (eddy) variability remains. A new technique is described for removing this variability using satellite altimeter measurements of the sea surface height. A new TS mean is produced, relating to the period from 2000 to 2007, and this is used to map a new oceanographic estimate of the MDT using an ocean circulation model. New geodetic estimates of the MDT are produced using geoid models that incorporate gravity measurements from the ongoing GRACE and GOCE satellite missions. These are compared with the new oceanographic estimate and validated against independent observations such as drifter speeds. The geodetic method produces realistic estimates of the mean surface circulation, thereby realizing the long time dream of oceanographers to observe the ocean circulation from space. The new oceanographic estimates are not as accurate, but the new TS mean contributes to improvements in the performance of ocean models, a necessary step in understanding and predicting the oceans. Coastal tide gauges can provide an accurate estimate of the alongshore tilt of the coastal MDT and this has been used to evaluate the above estimates. Temporal variability of the tilt along the coast of the South Atlantic Bight is used, with statistical methods and an ocean circulation ... |
author2 |
Department of Oceanography Doctor of Philosophy Professor Philip Woodworth Dr Dan Kelley Dr Youyu Lu Dr Jianliang Huang Dr Markus Kienast Dr Keith Thompson Not Applicable |
author |
Higginson, Simon |
author_facet |
Higginson, Simon |
author_sort |
Higginson, Simon |
title |
Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements |
title_short |
Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements |
title_full |
Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements |
title_fullStr |
Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements |
title_full_unstemmed |
Mapping and understanding the mean surface circulation of the North Atlantic: Insights from new geodetic and oceanographic measurements |
title_sort |
mapping and understanding the mean surface circulation of the north atlantic: insights from new geodetic and oceanographic measurements |
publishDate |
2012 |
url |
http://hdl.handle.net/10222/14866 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://hdl.handle.net/10222/14866 |
_version_ |
1800757313929216000 |