The University of Southampton
University of Southampton Institutional Repository

External and internal control of winter concentrations of nutrients (N, P and Si) in north-west European shelf seas

External and internal control of winter concentrations of nutrients (N, P and Si) in north-west European shelf seas
External and internal control of winter concentrations of nutrients (N, P and Si) in north-west European shelf seas
Nutrient data from five winter cruises since 1994 and the 40-year time series from the CYPRIS station in the Irish Sea are used to assess the controls of winter concentrations in the Celtic and Irish Seas and the Malin Shelf region of the north-west European shelf. At the Malin Shelf break, boundaries between ocean water, the shelf edge current and shelf waters were well defined by changes in salinity, temperature and concentrations of nutrients (nitrate + nitrite (N), phosphate (P) and silicate (Si)). Concentrations fell from oceanic values of 11.0 [mu]M N, 0.68 [mu]M P and 4.75 [mu]M Si to 7.4 [mu]M N, 0.53 [mu]M P and 3.3 [mu]M Si in open shelf sea waters. Across the Celtic Sea shelf break boundaries are less well defined. Areas of water with concentrations of nutrients below those off-shelf are detected in certain areas. Denitrification is a ubiquitous process on the shelf. The accumulated loss of nitrate relative to phosphate increases moving from the shelf break into the Irish Sea. Comparisons of estimated rates of denitrification with measured N:P ratios suggest waters on the Malin Shelf have an age of 400 days relative to ocean water crossing the shelf break. Across the Celtic Sea the transit time for water from the Atlantic Ocean into the central Irish Sea is six years, consistent with the complexity of water types and frontal structures. Concentrations at CYPRIS are consistent with the degree of nitrate loss from the water on route to the central Irish Sea. Relatively high concentrations of silicate measured at CYPRIS station indicate this location is more influenced by waters with an origin south of 53.5[deg]N than from the eastern Irish Sea
0272-7714
151-161
Hydes, D.J.
ac7371d4-c2b9-4926-bb77-ce58480ecff7
Gowen, R.J.
31e97c57-2642-42c4-a2c2-e3ce56a64771
Holliday, N.P.
358b0b33-f30b-44fd-a193-88365bbf2c79
Shammon, T.
8648d9f5-18a7-44d8-94bc-14fc63c34ff0
Mills, D.
74b63f08-96b2-4265-985c-f6073da45fb3
Hydes, D.J.
ac7371d4-c2b9-4926-bb77-ce58480ecff7
Gowen, R.J.
31e97c57-2642-42c4-a2c2-e3ce56a64771
Holliday, N.P.
358b0b33-f30b-44fd-a193-88365bbf2c79
Shammon, T.
8648d9f5-18a7-44d8-94bc-14fc63c34ff0
Mills, D.
74b63f08-96b2-4265-985c-f6073da45fb3

Hydes, D.J., Gowen, R.J., Holliday, N.P., Shammon, T. and Mills, D. (2004) External and internal control of winter concentrations of nutrients (N, P and Si) in north-west European shelf seas. Estuarine, Coastal and Shelf Science, 59 (1), 151-161. (doi:10.1016/j.ecss.2003.08.004).

Record type: Article

Abstract

Nutrient data from five winter cruises since 1994 and the 40-year time series from the CYPRIS station in the Irish Sea are used to assess the controls of winter concentrations in the Celtic and Irish Seas and the Malin Shelf region of the north-west European shelf. At the Malin Shelf break, boundaries between ocean water, the shelf edge current and shelf waters were well defined by changes in salinity, temperature and concentrations of nutrients (nitrate + nitrite (N), phosphate (P) and silicate (Si)). Concentrations fell from oceanic values of 11.0 [mu]M N, 0.68 [mu]M P and 4.75 [mu]M Si to 7.4 [mu]M N, 0.53 [mu]M P and 3.3 [mu]M Si in open shelf sea waters. Across the Celtic Sea shelf break boundaries are less well defined. Areas of water with concentrations of nutrients below those off-shelf are detected in certain areas. Denitrification is a ubiquitous process on the shelf. The accumulated loss of nitrate relative to phosphate increases moving from the shelf break into the Irish Sea. Comparisons of estimated rates of denitrification with measured N:P ratios suggest waters on the Malin Shelf have an age of 400 days relative to ocean water crossing the shelf break. Across the Celtic Sea the transit time for water from the Atlantic Ocean into the central Irish Sea is six years, consistent with the complexity of water types and frontal structures. Concentrations at CYPRIS are consistent with the degree of nitrate loss from the water on route to the central Irish Sea. Relatively high concentrations of silicate measured at CYPRIS station indicate this location is more influenced by waters with an origin south of 53.5[deg]N than from the eastern Irish Sea

This record has no associated files available for download.

More information

Published date: 2004

Identifiers

Local EPrints ID: 1281
URI: http://eprints.soton.ac.uk/id/eprint/1281
ISSN: 0272-7714
PURE UUID: 30c76d19-2bb8-45c5-a790-32fcfd7e9551

Catalogue record

Date deposited: 14 Apr 2004
Last modified: 15 Mar 2024 04:42

Export record

Altmetrics

Contributors

Author: D.J. Hydes
Author: R.J. Gowen
Author: N.P. Holliday
Author: T. Shammon
Author: D. Mills

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.

×