The University of Southampton
University of Southampton Institutional Repository

Nutrient streams in the North Atlantic: Advective pathways of inorganic and dissolved organic nutrients

Nutrient streams in the North Atlantic: Advective pathways of inorganic and dissolved organic nutrients
Nutrient streams in the North Atlantic: Advective pathways of inorganic and dissolved organic nutrients
The Gulf Stream provides a ‘nutrient stream,’ an advective flux of nutrients carried in sub-surface waters, redistributing nutrients from the tropics to the mid latitudes. There is a dramatic downstream strengthening in the full depth, volume and nitrate transport diagnosed from synoptic measurements along three sections: 32 Sv and 300 kmol s?1 at 27°N, increasing to 66.7 Sv and 940 kmol s?1 at 35.5°N, and 149.5 Sv and 2100 kmol s?1 at 36.5°N; the transport estimates have uncertainties reaching 10% of their values. The transport-weighted nitrate concentration carried by the Gulf Stream generally decreases downstream in light layers (? ? < 26.8), but increases in denser layers between 35.5°N and 36.5°N. The fraction of nutrients from regeneration within the upper thermocline slightly decreases downstream between 35.5°N and 36.5°N. Hence, the downstream variations in the nitrate concentrations carried by the Gulf Stream are probably due to lateral exchange along isopycnals, rather than diapycnal transfer or biological consumption and regeneration. The Gulf Stream also transports dissolved organic nitrogen (DON) northward within lighter upper waters, providing up to 26% of the total nitrogen transport. An accompanying model study reveals coherent nitrate and DON streams, including significant lateral exchange, running from the tropics along the western boundary of the subtropical gyre and following the separated jet along the inter-gyre boundary. The combined nitrate and DON transport along light surfaces (? ? < 26.8) remains within the subtropical gyre, while the larger nitrate transport along denser surfaces passes into the subpolar gyre, sustaining high-latitude productivity.
0886-6236
GB4008
Williams, Richard G.
2155309e-1c07-4365-b46a-04baeb2fb63c
McDonagh, Elaine
47e26eeb-b774-4068-af07-31847e42b977
Roussenov, Vassil M.
dd3b39c7-9a7a-476d-b7eb-4e5add1446a1
Torres-Valdes, Sinhue
50398d55-4df9-4b9e-a431-16936300650c
King, Brian
960f44b4-cc9c-4f77-b3c8-775530ac0061
Sanders, Richard
02c163c1-8f5e-49ad-857c-d28f7da66c65
Hansell, Dennis A.
d4f0a3af-ca20-4791-a794-e52cbd56d654
Williams, Richard G.
2155309e-1c07-4365-b46a-04baeb2fb63c
McDonagh, Elaine
47e26eeb-b774-4068-af07-31847e42b977
Roussenov, Vassil M.
dd3b39c7-9a7a-476d-b7eb-4e5add1446a1
Torres-Valdes, Sinhue
50398d55-4df9-4b9e-a431-16936300650c
King, Brian
960f44b4-cc9c-4f77-b3c8-775530ac0061
Sanders, Richard
02c163c1-8f5e-49ad-857c-d28f7da66c65
Hansell, Dennis A.
d4f0a3af-ca20-4791-a794-e52cbd56d654

Williams, Richard G., McDonagh, Elaine, Roussenov, Vassil M., Torres-Valdes, Sinhue, King, Brian, Sanders, Richard and Hansell, Dennis A. (2011) Nutrient streams in the North Atlantic: Advective pathways of inorganic and dissolved organic nutrients. Global Biogeochemical Cycles, 25 (4), GB4008. (doi:10.1029/2010GB003853).

Record type: Article

Abstract

The Gulf Stream provides a ‘nutrient stream,’ an advective flux of nutrients carried in sub-surface waters, redistributing nutrients from the tropics to the mid latitudes. There is a dramatic downstream strengthening in the full depth, volume and nitrate transport diagnosed from synoptic measurements along three sections: 32 Sv and 300 kmol s?1 at 27°N, increasing to 66.7 Sv and 940 kmol s?1 at 35.5°N, and 149.5 Sv and 2100 kmol s?1 at 36.5°N; the transport estimates have uncertainties reaching 10% of their values. The transport-weighted nitrate concentration carried by the Gulf Stream generally decreases downstream in light layers (? ? < 26.8), but increases in denser layers between 35.5°N and 36.5°N. The fraction of nutrients from regeneration within the upper thermocline slightly decreases downstream between 35.5°N and 36.5°N. Hence, the downstream variations in the nitrate concentrations carried by the Gulf Stream are probably due to lateral exchange along isopycnals, rather than diapycnal transfer or biological consumption and regeneration. The Gulf Stream also transports dissolved organic nitrogen (DON) northward within lighter upper waters, providing up to 26% of the total nitrogen transport. An accompanying model study reveals coherent nitrate and DON streams, including significant lateral exchange, running from the tropics along the western boundary of the subtropical gyre and following the separated jet along the inter-gyre boundary. The combined nitrate and DON transport along light surfaces (? ? < 26.8) remains within the subtropical gyre, while the larger nitrate transport along denser surfaces passes into the subpolar gyre, sustaining high-latitude productivity.

This record has no associated files available for download.

More information

Published date: 2011
Organisations: Marine Biogeochemistry, Marine Physics and Ocean Climate

Identifiers

Local EPrints ID: 207399
URI: http://eprints.soton.ac.uk/id/eprint/207399
ISSN: 0886-6236
PURE UUID: 08f0c772-7f2d-4a7c-a43f-29ba03394237

Catalogue record

Date deposited: 09 Jan 2012 17:03
Last modified: 14 Mar 2024 04:39

Export record

Altmetrics

Contributors

Author: Richard G. Williams
Author: Elaine McDonagh
Author: Vassil M. Roussenov
Author: Sinhue Torres-Valdes
Author: Brian King
Author: Richard Sanders
Author: Dennis A. Hansell

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.

×