Kinematics of surface currents at the northern margin of the Gulf of Cádiz
<p>The subtidal surface water circulation at the northern margin of the Gulf of Cádiz, at the southern extremity of the Iberian upwelling system, is described based on validated hourly high-frequency radar measurements from 2016 to 2020. Statistical analyses (mean, standard deviation, eccentri...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Copernicus Publications
2022-08-01
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| Series: | Ocean Science |
| Online Access: | https://os.copernicus.org/articles/18/1183/2022/os-18-1183-2022.pdf |
| _version_ | 1811314516403683328 |
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| author | L. de Oliveira Júnior P. Relvas E. Garel |
| author_facet | L. de Oliveira Júnior P. Relvas E. Garel |
| author_sort | L. de Oliveira Júnior |
| collection | DOAJ |
| description | <p>The subtidal surface water circulation at the northern
margin of the Gulf of Cádiz, at the southern extremity of the Iberian
upwelling system, is described based on validated hourly high-frequency
radar measurements from 2016 to 2020. Statistical analyses (mean, standard
deviation, eccentricity and empirical orthogonal functions) are applied to
the dataset, which is completed with ADCP time series from multiple moorings
at five inner-shelf stations and ERA5 wind. Off the shelf, the main circulation
pattern consists of a slope current, best developed in summer when
north-westerlies dominate, in particular at the most exposed western region.
Mechanisms other than upwelling must contribute to this flow in order to
explain its seasonal persistence. The slope circulation reverses for
regional wind events with an east component <span class="inline-formula">></span> 10 m s<span class="inline-formula"><sup>−1</sup></span>,
approximately. On the shelf, currents are mainly alongshore and balanced.
The circulation is generally continuous along the coast, except for weak
(<span class="inline-formula"><</span> 0.1 m s<span class="inline-formula"><sup>−1</sup></span>, broadly) poleward flows. In the latter case, the
flow tends to remain equatorward near Cape Santa Maria. In winter, coastal
poleward flows often extend over the entire margin and are mainly
wind-driven. In summer, these flows generally consist of coastal counter
currents (CCCs) with the poleward direction opposed to that of the slope
current. The CCCs are associated with significant cyclonic recirculation,
strongest to the west, where a transient eddy is shortly observed for weak wind
stress. This circulation develops after periods of strong north-westerlies,
supporting that CCCs result from the imbalance of a regional alongshore
pressure gradient.</p> |
| first_indexed | 2024-04-13T11:13:00Z |
| format | Article |
| id | doaj.art-2912d40c2b6449cc80dd0881c46ca15a |
| institution | Directory Open Access Journal |
| issn | 1812-0784 1812-0792 |
| language | English |
| last_indexed | 2024-04-13T11:13:00Z |
| publishDate | 2022-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Ocean Science |
| spelling | doaj.art-2912d40c2b6449cc80dd0881c46ca15a2022-12-22T02:49:03ZengCopernicus PublicationsOcean Science1812-07841812-07922022-08-01181183120210.5194/os-18-1183-2022Kinematics of surface currents at the northern margin of the Gulf of CádizL. de Oliveira Júnior0P. Relvas1E. Garel2Centre for Marine and Environmental Research (CIMA), University of Algarve, Faro, 8005-139, PortugalCentre of Marine Sciences (CCMAR), University of Algarve, Faro, 8005-139, PortugalCentre for Marine and Environmental Research (CIMA), University of Algarve, Faro, 8005-139, Portugal<p>The subtidal surface water circulation at the northern margin of the Gulf of Cádiz, at the southern extremity of the Iberian upwelling system, is described based on validated hourly high-frequency radar measurements from 2016 to 2020. Statistical analyses (mean, standard deviation, eccentricity and empirical orthogonal functions) are applied to the dataset, which is completed with ADCP time series from multiple moorings at five inner-shelf stations and ERA5 wind. Off the shelf, the main circulation pattern consists of a slope current, best developed in summer when north-westerlies dominate, in particular at the most exposed western region. Mechanisms other than upwelling must contribute to this flow in order to explain its seasonal persistence. The slope circulation reverses for regional wind events with an east component <span class="inline-formula">></span> 10 m s<span class="inline-formula"><sup>−1</sup></span>, approximately. On the shelf, currents are mainly alongshore and balanced. The circulation is generally continuous along the coast, except for weak (<span class="inline-formula"><</span> 0.1 m s<span class="inline-formula"><sup>−1</sup></span>, broadly) poleward flows. In the latter case, the flow tends to remain equatorward near Cape Santa Maria. In winter, coastal poleward flows often extend over the entire margin and are mainly wind-driven. In summer, these flows generally consist of coastal counter currents (CCCs) with the poleward direction opposed to that of the slope current. The CCCs are associated with significant cyclonic recirculation, strongest to the west, where a transient eddy is shortly observed for weak wind stress. This circulation develops after periods of strong north-westerlies, supporting that CCCs result from the imbalance of a regional alongshore pressure gradient.</p>https://os.copernicus.org/articles/18/1183/2022/os-18-1183-2022.pdf |
| spellingShingle | L. de Oliveira Júnior P. Relvas E. Garel Kinematics of surface currents at the northern margin of the Gulf of Cádiz Ocean Science |
| title | Kinematics of surface currents at the northern margin of the Gulf of Cádiz |
| title_full | Kinematics of surface currents at the northern margin of the Gulf of Cádiz |
| title_fullStr | Kinematics of surface currents at the northern margin of the Gulf of Cádiz |
| title_full_unstemmed | Kinematics of surface currents at the northern margin of the Gulf of Cádiz |
| title_short | Kinematics of surface currents at the northern margin of the Gulf of Cádiz |
| title_sort | kinematics of surface currents at the northern margin of the gulf of cadiz |
| url | https://os.copernicus.org/articles/18/1183/2022/os-18-1183-2022.pdf |
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