Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre
Between 1996 and the mid-2000s the upper waters (200¿700 m) of the Rockall Trough became warmer (+0.72 °C), saltier (+0.088) and reduced in nitrate and phosphate (¿2.00 µM and ¿0.14 µM respectively). These changes, out-with calculated errors, can be explained by the varying influence of southern ver...
Published in: | Deep Sea Research Part I: Oceanographic Research Papers |
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2013
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Online Access: | https://pure.uhi.ac.uk/en/publications/caaadaf1-f945-424d-a20d-90a22037298d https://doi.org/10.1016/j.dsr.2013.08.007 https://pureadmin.uhi.ac.uk/ws/files/2050281/cj_accepted.pdf |
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ftuhipublicatio:oai:pure.atira.dk:publications/caaadaf1-f945-424d-a20d-90a22037298d 2024-06-23T07:55:19+00:00 Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre Johnson, Clare Inall, Mark Häkkinen, Sirpa 2013-12-01 application/pdf https://pure.uhi.ac.uk/en/publications/caaadaf1-f945-424d-a20d-90a22037298d https://doi.org/10.1016/j.dsr.2013.08.007 https://pureadmin.uhi.ac.uk/ws/files/2050281/cj_accepted.pdf eng eng https://pure.uhi.ac.uk/en/publications/caaadaf1-f945-424d-a20d-90a22037298d info:eu-repo/semantics/openAccess Johnson , C , Inall , M & Häkkinen , S 2013 , ' Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre ' , Deep-Sea Research Part I-Oceanographic Research Papers , vol. 82 , no. n/a , n/a , pp. 95-107 . https://doi.org/10.1016/j.dsr.2013.08.007 article 2013 ftuhipublicatio https://doi.org/10.1016/j.dsr.2013.08.007 2024-06-10T23:47:56Z Between 1996 and the mid-2000s the upper waters (200¿700 m) of the Rockall Trough became warmer (+0.72 °C), saltier (+0.088) and reduced in nitrate and phosphate (¿2.00 µM and ¿0.14 µM respectively). These changes, out-with calculated errors, can be explained by the varying influence of southern versus subpolar water masses in the basin as the Subpolar Gyre weakened and contracted. Upper water properties strongly correlate with a measure of the strength of the Subpolar Gyre (the first principal component of sea surface height over the Subpolar North Atlantic) prior to the mid-2000s. As the gyre weakens, the upper layers of the trough become warmer (r¿0.85), more saline (r¿0.86) and reduced in nitrate and phosphate (r+0.81 and r+0.87 respectively). Further the proportion of subpolar waters in the basin decreases from around 50% to less than 20% (r+0. 88). Since the mid¿2000s the Subpolar Gyre has been particularly weak. During this period temperatures decreased slightly (¿0.21 °C), salinities remained near constant (35.410±0.005) and phosphate levels low and stable (0.68±0.02 µM). These relative lack of changes are thought to be related to the maximum proportion of southern water masses within the Rockall Trough having been reached. Thus the upper water properties are no longer controlled by changes in the relative importance of different water masses in the basin (as prior to the mid-2000s), but rather a different process. We suggest that when the gyre is particularly weak the interannual changes in upper water properties in the Rockall Trough reflect changes in the source properties of the southern water masses. Since the early-2000s the Subpolar Gyre has been weaker than observed since 1992, or modelled since 1960¿1970. Hence upper waters within the Rockall Trough may be warmer, saltier and more depleted in nitrate and phosphate than at any time in the last half century. Article in Journal/Newspaper North Atlantic Northeast Atlantic University of the Highlands and Islands: Research Database of UHI Rockall Trough ENVELOPE(-15.036,-15.036,53.825,53.825) Deep Sea Research Part I: Oceanographic Research Papers 82 95 107 |
institution |
Open Polar |
collection |
University of the Highlands and Islands: Research Database of UHI |
op_collection_id |
ftuhipublicatio |
language |
English |
description |
Between 1996 and the mid-2000s the upper waters (200¿700 m) of the Rockall Trough became warmer (+0.72 °C), saltier (+0.088) and reduced in nitrate and phosphate (¿2.00 µM and ¿0.14 µM respectively). These changes, out-with calculated errors, can be explained by the varying influence of southern versus subpolar water masses in the basin as the Subpolar Gyre weakened and contracted. Upper water properties strongly correlate with a measure of the strength of the Subpolar Gyre (the first principal component of sea surface height over the Subpolar North Atlantic) prior to the mid-2000s. As the gyre weakens, the upper layers of the trough become warmer (r¿0.85), more saline (r¿0.86) and reduced in nitrate and phosphate (r+0.81 and r+0.87 respectively). Further the proportion of subpolar waters in the basin decreases from around 50% to less than 20% (r+0. 88). Since the mid¿2000s the Subpolar Gyre has been particularly weak. During this period temperatures decreased slightly (¿0.21 °C), salinities remained near constant (35.410±0.005) and phosphate levels low and stable (0.68±0.02 µM). These relative lack of changes are thought to be related to the maximum proportion of southern water masses within the Rockall Trough having been reached. Thus the upper water properties are no longer controlled by changes in the relative importance of different water masses in the basin (as prior to the mid-2000s), but rather a different process. We suggest that when the gyre is particularly weak the interannual changes in upper water properties in the Rockall Trough reflect changes in the source properties of the southern water masses. Since the early-2000s the Subpolar Gyre has been weaker than observed since 1992, or modelled since 1960¿1970. Hence upper waters within the Rockall Trough may be warmer, saltier and more depleted in nitrate and phosphate than at any time in the last half century. |
format |
Article in Journal/Newspaper |
author |
Johnson, Clare Inall, Mark Häkkinen, Sirpa |
spellingShingle |
Johnson, Clare Inall, Mark Häkkinen, Sirpa Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre |
author_facet |
Johnson, Clare Inall, Mark Häkkinen, Sirpa |
author_sort |
Johnson, Clare |
title |
Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre |
title_short |
Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre |
title_full |
Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre |
title_fullStr |
Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre |
title_full_unstemmed |
Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre |
title_sort |
declining nutrient concentrations in the northeast atlantic as a result of a weakening subpolar gyre |
publishDate |
2013 |
url |
https://pure.uhi.ac.uk/en/publications/caaadaf1-f945-424d-a20d-90a22037298d https://doi.org/10.1016/j.dsr.2013.08.007 https://pureadmin.uhi.ac.uk/ws/files/2050281/cj_accepted.pdf |
long_lat |
ENVELOPE(-15.036,-15.036,53.825,53.825) |
geographic |
Rockall Trough |
geographic_facet |
Rockall Trough |
genre |
North Atlantic Northeast Atlantic |
genre_facet |
North Atlantic Northeast Atlantic |
op_source |
Johnson , C , Inall , M & Häkkinen , S 2013 , ' Declining nutrient concentrations in the northeast Atlantic as a result of a weakening Subpolar Gyre ' , Deep-Sea Research Part I-Oceanographic Research Papers , vol. 82 , no. n/a , n/a , pp. 95-107 . https://doi.org/10.1016/j.dsr.2013.08.007 |
op_relation |
https://pure.uhi.ac.uk/en/publications/caaadaf1-f945-424d-a20d-90a22037298d |
op_rights |
info:eu-repo/semantics/openAccess |
op_doi |
https://doi.org/10.1016/j.dsr.2013.08.007 |
container_title |
Deep Sea Research Part I: Oceanographic Research Papers |
container_volume |
82 |
container_start_page |
95 |
op_container_end_page |
107 |
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1802647873881374720 |