The University of Southampton
University of Southampton Institutional Repository

A study of currents in the Southern Ocean using satellite altimeter and model data

A study of currents in the Southern Ocean using satellite altimeter and model data
A study of currents in the Southern Ocean using satellite altimeter and model data

The aims of the project are outlined and the satellite altimeter is introduced as a new method for the physical oceanographer to study ocean dynamics. The principles of the satellite altimeter are explained and a description of the sources of error found in the data is given, together with two possible methods for removal of residual errors. The principles of primitive equation ocean circulation models are outlined and the Fine Resolution Antarctic Model (FRAM) is introduced. Methods of hydrographic data collection are discussed and historical data on the circulation of the Southern Ocean are reviewed. The methods for Geosat data extraction, quality control and error correction used in the study are discussed. Data processed by collinear techniques have been used to obtain height profiles along tracks in two regions of the Southern Ocean; South of Africa and in the Central South Pacific. Mesoscale variability fields calculated from the along track altimeter data are presented and explained in terms of historical in situ current data and bottom topography. Geostrophic current speeds calculated from the residual height profiles yield velocity anomalies of the order of 20 cm s"1 for the Antarctic Circumpolar Current (ACC) and up to 1.38 m s1 for the Agulhas Current System, similar to values obtained by in situ measurements. Autocorrelation function calculations show that the characteristic length scales of height anomalies in the ACC are smaller than those of the Agulhas Current System. The FRAM data set is used as a source of artificial sea surface heights to give model altimeter data which are processed and analyzed for the Geosat study regions. The resultant variability fields are compared with the Geosat results. The effects of Geosat's sampling strategy and altimeter processing on the FRAM data are analyzed and are given as an indication of the possible reliability of Geosat variability fields. The results of feature recognition and autocorrelation function analyses are compared to those from Geosat both as a verification for the FRAM mesoscale circulation and as an aid to altimeter data interpretation.

University of Southampton
Snaith, Helen Mary
e3fe1287-51bd-452a-9c04-b2114b32bbf1
Snaith, Helen Mary
e3fe1287-51bd-452a-9c04-b2114b32bbf1

Snaith, Helen Mary (1992) A study of currents in the Southern Ocean using satellite altimeter and model data. University of Southampton, Doctoral Thesis.

Record type: Thesis (Doctoral)

Abstract

The aims of the project are outlined and the satellite altimeter is introduced as a new method for the physical oceanographer to study ocean dynamics. The principles of the satellite altimeter are explained and a description of the sources of error found in the data is given, together with two possible methods for removal of residual errors. The principles of primitive equation ocean circulation models are outlined and the Fine Resolution Antarctic Model (FRAM) is introduced. Methods of hydrographic data collection are discussed and historical data on the circulation of the Southern Ocean are reviewed. The methods for Geosat data extraction, quality control and error correction used in the study are discussed. Data processed by collinear techniques have been used to obtain height profiles along tracks in two regions of the Southern Ocean; South of Africa and in the Central South Pacific. Mesoscale variability fields calculated from the along track altimeter data are presented and explained in terms of historical in situ current data and bottom topography. Geostrophic current speeds calculated from the residual height profiles yield velocity anomalies of the order of 20 cm s"1 for the Antarctic Circumpolar Current (ACC) and up to 1.38 m s1 for the Agulhas Current System, similar to values obtained by in situ measurements. Autocorrelation function calculations show that the characteristic length scales of height anomalies in the ACC are smaller than those of the Agulhas Current System. The FRAM data set is used as a source of artificial sea surface heights to give model altimeter data which are processed and analyzed for the Geosat study regions. The resultant variability fields are compared with the Geosat results. The effects of Geosat's sampling strategy and altimeter processing on the FRAM data are analyzed and are given as an indication of the possible reliability of Geosat variability fields. The results of feature recognition and autocorrelation function analyses are compared to those from Geosat both as a verification for the FRAM mesoscale circulation and as an aid to altimeter data interpretation.

Text
368547.pdf - Version of Record
Available under License University of Southampton Thesis Licence.
Download (19MB)

More information

Published date: 1992

Identifiers

Local EPrints ID: 461961
URI: http://eprints.soton.ac.uk/id/eprint/461961
PURE UUID: 92fccc6d-48b0-44d0-b8b4-0deeb2d9aadf

Catalogue record

Date deposited: 04 Jul 2022 18:59
Last modified: 16 Mar 2024 18:52

Export record

Contributors

Author: Helen Mary Snaith

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of http://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×