Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas
17 páginas, 1 apéndice, 7 figuras, 3 tablas A set of hydrographic surveys were carried out in the Ría of Vigo (NW Spain) at 2–4 d intervals during four 2–3 week periods in 1997, covering contrasting seasons. Residual exchange fluxes with the adjacent shelf were estimated with a 2-D, non-steady-state...
Published in: | Estuarine, Coastal and Shelf Science |
---|---|
Main Authors: | , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
Elsevier
2000
|
Subjects: | |
Online Access: | http://hdl.handle.net/10261/56998 https://doi.org/10.1006/ecss.2000.0714 |
id |
ftcsic:oai:digital.csic.es:10261/56998 |
---|---|
record_format |
openpolar |
spelling |
ftcsic:oai:digital.csic.es:10261/56998 2024-02-11T10:06:50+01:00 Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas Álvarez-Salgado, Xosé Antón Gago, Jesús Martín Míguez, Belén Gilcoto, Miguel Pérez, Fiz F. 2000 http://hdl.handle.net/10261/56998 https://doi.org/10.1006/ecss.2000.0714 en eng Elsevier http://dx.doi.org/10.1006/ecss.2000.0714 Estuarine, Coastal and Shelf Science 51(6): 821-837 (2000) 0272-7714 http://hdl.handle.net/10261/56998 doi:10.1006/ecss.2000.0714 open Upwelling Downwelling Outwelling Box models Spanish rias artículo http://purl.org/coar/resource_type/c_6501 2000 ftcsic https://doi.org/10.1006/ecss.2000.0714 2024-01-16T09:41:04Z 17 páginas, 1 apéndice, 7 figuras, 3 tablas A set of hydrographic surveys were carried out in the Ría of Vigo (NW Spain) at 2–4 d intervals during four 2–3 week periods in 1997, covering contrasting seasons. Residual exchange fluxes with the adjacent shelf were estimated with a 2-D, non-steady-state, salinity–temperature weighted box model. Exchange fluxes consist of a steady-state term (dependent on the variability of continental runoff) and a non-steady-state term (dependent on the time changes of density gradients in the embayment). More than 95% of the short-time-scale variability of the exchange fluxes in the middle and outer rı´a can be explained by the non-steady-state term that, in turns, is correlated (R2>75%) with the offshore Ekman transport. Conversely, 96% of the variability of exchange fluxes in the inner rı´a rely on the steady-state term. The outer and middle rı´a are under the direct influence of coastal upwelling, which enhances the positive residual circulation pattern by an order of magnitude: from 102 to 103 m3 s 1. On the contrary, downwelling provokes a reversal of the circulation in the outer rı´a. The position of the downwelling front along the embayment depends on the relative importance of Ekman transport (Qx, m3 s 1 km 1) and continental runoff (R, m3 s 1). When Qx/R>7 2 the reversal of the circulation affects the middle rı´a. Our results are representative for the ‘Rı´as Baixas’, four large coastal indentations in NW Spain. During the upwelling season (spring and summer), 60% of shelf surface waters off the ‘Rı´as Baixas’ consist of fresh Eastern North Atlantic Central Water (ENACW) upwelled in situ. The remaining 40% consists of upwelled ENACW that previously enters the rı´as and it is subsequently outwelled after thermohaline modification. During the downwelling season (autumn and winter), 40% of the warm and salty oceanic subtropic surface water, which piled on the shelf by the predominant southerly winds, enters the rías. Financial support for this work came from CICYT ... Article in Journal/Newspaper North Atlantic Digital.CSIC (Spanish National Research Council) Estuarine, Coastal and Shelf Science 51 6 821 837 |
institution |
Open Polar |
collection |
Digital.CSIC (Spanish National Research Council) |
op_collection_id |
ftcsic |
language |
English |
topic |
Upwelling Downwelling Outwelling Box models Spanish rias |
spellingShingle |
Upwelling Downwelling Outwelling Box models Spanish rias Álvarez-Salgado, Xosé Antón Gago, Jesús Martín Míguez, Belén Gilcoto, Miguel Pérez, Fiz F. Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas |
topic_facet |
Upwelling Downwelling Outwelling Box models Spanish rias |
description |
17 páginas, 1 apéndice, 7 figuras, 3 tablas A set of hydrographic surveys were carried out in the Ría of Vigo (NW Spain) at 2–4 d intervals during four 2–3 week periods in 1997, covering contrasting seasons. Residual exchange fluxes with the adjacent shelf were estimated with a 2-D, non-steady-state, salinity–temperature weighted box model. Exchange fluxes consist of a steady-state term (dependent on the variability of continental runoff) and a non-steady-state term (dependent on the time changes of density gradients in the embayment). More than 95% of the short-time-scale variability of the exchange fluxes in the middle and outer rı´a can be explained by the non-steady-state term that, in turns, is correlated (R2>75%) with the offshore Ekman transport. Conversely, 96% of the variability of exchange fluxes in the inner rı´a rely on the steady-state term. The outer and middle rı´a are under the direct influence of coastal upwelling, which enhances the positive residual circulation pattern by an order of magnitude: from 102 to 103 m3 s 1. On the contrary, downwelling provokes a reversal of the circulation in the outer rı´a. The position of the downwelling front along the embayment depends on the relative importance of Ekman transport (Qx, m3 s 1 km 1) and continental runoff (R, m3 s 1). When Qx/R>7 2 the reversal of the circulation affects the middle rı´a. Our results are representative for the ‘Rı´as Baixas’, four large coastal indentations in NW Spain. During the upwelling season (spring and summer), 60% of shelf surface waters off the ‘Rı´as Baixas’ consist of fresh Eastern North Atlantic Central Water (ENACW) upwelled in situ. The remaining 40% consists of upwelled ENACW that previously enters the rı´as and it is subsequently outwelled after thermohaline modification. During the downwelling season (autumn and winter), 40% of the warm and salty oceanic subtropic surface water, which piled on the shelf by the predominant southerly winds, enters the rías. Financial support for this work came from CICYT ... |
format |
Article in Journal/Newspaper |
author |
Álvarez-Salgado, Xosé Antón Gago, Jesús Martín Míguez, Belén Gilcoto, Miguel Pérez, Fiz F. |
author_facet |
Álvarez-Salgado, Xosé Antón Gago, Jesús Martín Míguez, Belén Gilcoto, Miguel Pérez, Fiz F. |
author_sort |
Álvarez-Salgado, Xosé Antón |
title |
Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas |
title_short |
Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas |
title_full |
Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas |
title_fullStr |
Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas |
title_full_unstemmed |
Surface waters of the NW Iberian margin: Upwelling on the shelf versus outwelling of upwelled waters from the Rías Baixas |
title_sort |
surface waters of the nw iberian margin: upwelling on the shelf versus outwelling of upwelled waters from the rías baixas |
publisher |
Elsevier |
publishDate |
2000 |
url |
http://hdl.handle.net/10261/56998 https://doi.org/10.1006/ecss.2000.0714 |
genre |
North Atlantic |
genre_facet |
North Atlantic |
op_relation |
http://dx.doi.org/10.1006/ecss.2000.0714 Estuarine, Coastal and Shelf Science 51(6): 821-837 (2000) 0272-7714 http://hdl.handle.net/10261/56998 doi:10.1006/ecss.2000.0714 |
op_rights |
open |
op_doi |
https://doi.org/10.1006/ecss.2000.0714 |
container_title |
Estuarine, Coastal and Shelf Science |
container_volume |
51 |
container_issue |
6 |
container_start_page |
821 |
op_container_end_page |
837 |
_version_ |
1790604818141675520 |