The University of Southampton
University of Southampton Institutional Repository

Sub-mesoscale structure and the development of an eddy in the Subantarctic Front north of the Crozet Islands

Sub-mesoscale structure and the development of an eddy in the Subantarctic Front north of the Crozet Islands
Sub-mesoscale structure and the development of an eddy in the Subantarctic Front north of the Crozet Islands
Two stations only 20 km apart were observed to have quite different biological and biogeochemical characteristics. The first site had low concentrations of chlorophyll and sufficient nutrients to support phytoplankton growth. The second site had high concentrations of chlorophyll, depleted nutrient concentrations and significant export of phytodetrital material had taken place. The two sites were located in the Polar Frontal Zone of the Southern Ocean to the northwest of the Crozet Islands. The main physical difference between the two sites was in the depth of the mixed layer. At the first site, the mixed layer was deep and well mixed, whereas the second site had a shallow, stratified layer; otherwise the horizontal gradients of physical properties were weak. Survey data from the surrounding area showed that the productive site was located on the edge of a filament of water drawn into a developing meander of the Subantarctic Front. Remotely sensed data provided a history of the growth of the meander in the Subantarctic Front and its development into an eddy in the Polar Frontal Zone. The dynamics associated with the filament in the meander were clearly important in driving the primary productivity, as an intrusion of saline water into adjacent fresher water generated a shallow mixed layer and conditions suitable for phytoplankton growth. The dynamics promoting conditions favourable to phytoplankton growth continued to operate as chlorophyll was enhanced in the eddy after the main bloom had died away. Later measurements suggested that the surface layer had changed from diatom dominated to a coccolithophore or calcite-rich community.
Mesoscale features, Oceanic eddies, Ocean circulation, Algal bloom, Subantarctic Front, Southern Ocean, Indian Ocean, Polar Frontal Zone, 45°S, 50°E
0967-0645
1930-1948
Read, J.F.
913784a2-30c1-4aa7-aa60-63824998e845
Pollard, R.T.
0c78b909-8a95-4bd2-82fd-9b11022888fd
Allen, J.T.
b251a62b-f443-4591-b695-9aa8c4d73741
Read, J.F.
913784a2-30c1-4aa7-aa60-63824998e845
Pollard, R.T.
0c78b909-8a95-4bd2-82fd-9b11022888fd
Allen, J.T.
b251a62b-f443-4591-b695-9aa8c4d73741

Read, J.F., Pollard, R.T. and Allen, J.T. (2007) Sub-mesoscale structure and the development of an eddy in the Subantarctic Front north of the Crozet Islands. Deep Sea Research Part II: Topical Studies in Oceanography, 54 (18-20), 1930-1948. (doi:10.1016/j.dsr2.2007.06.013).

Record type: Article

Abstract

Two stations only 20 km apart were observed to have quite different biological and biogeochemical characteristics. The first site had low concentrations of chlorophyll and sufficient nutrients to support phytoplankton growth. The second site had high concentrations of chlorophyll, depleted nutrient concentrations and significant export of phytodetrital material had taken place. The two sites were located in the Polar Frontal Zone of the Southern Ocean to the northwest of the Crozet Islands. The main physical difference between the two sites was in the depth of the mixed layer. At the first site, the mixed layer was deep and well mixed, whereas the second site had a shallow, stratified layer; otherwise the horizontal gradients of physical properties were weak. Survey data from the surrounding area showed that the productive site was located on the edge of a filament of water drawn into a developing meander of the Subantarctic Front. Remotely sensed data provided a history of the growth of the meander in the Subantarctic Front and its development into an eddy in the Polar Frontal Zone. The dynamics associated with the filament in the meander were clearly important in driving the primary productivity, as an intrusion of saline water into adjacent fresher water generated a shallow mixed layer and conditions suitable for phytoplankton growth. The dynamics promoting conditions favourable to phytoplankton growth continued to operate as chlorophyll was enhanced in the eddy after the main bloom had died away. Later measurements suggested that the surface layer had changed from diatom dominated to a coccolithophore or calcite-rich community.

This record has no associated files available for download.

More information

Published date: 2007
Keywords: Mesoscale features, Oceanic eddies, Ocean circulation, Algal bloom, Subantarctic Front, Southern Ocean, Indian Ocean, Polar Frontal Zone, 45°S, 50°E

Identifiers

Local EPrints ID: 49506
URI: http://eprints.soton.ac.uk/id/eprint/49506
ISSN: 0967-0645
PURE UUID: 0031bdba-2331-444d-aff1-f5dcd0f85c96

Catalogue record

Date deposited: 12 Nov 2007
Last modified: 15 Mar 2024 09:56

Export record

Altmetrics

Contributors

Author: J.F. Read
Author: R.T. Pollard
Author: J.T. Allen

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.

×