Wind influence on surface current variability in the Ibiza Channel from HF Radar

Autor: Arancha Lana, Julien Marmain, Joaquín Tintoré, Alejandro Orfila, Vicente Fernandez
Přispěvatelé: European Commission, Consejo Superior de Investigaciones Científicas (España)
Rok vydání: 2016
Předmět:
Zdroj: Ocean Dynamics
Digital.CSIC. Repositorio Institucional del CSIC
instname
ISSN: 1616-7228
Popis: Surface current variability is investigated using 2.5 years of continuous velocity measurements from an high frequency radar (HFR) located in the Ibiza Channel (Western Mediterranean Sea). The Ibiza Channel is identified as a key geographical feature for the exchange of water masses but still poorly documented. Operational, quality controlled, HFR derived velocities are provided by the Balearic Islands Coastal Observing and Forecasting System (SOCIB). They are assessed by performing statistical comparisons with current-meter, ADCP, and surface lagrangian drifters. HFR system does not show significant bias, and its accuracy is in accordance with previous studies performed in other areas. The main surface circulation patterns are deduced from an EOF analysis. The first three modes represent almost 70 % of the total variability. A cross-correlation analysis between zonal and meridional wind components and the temporal amplitudes of the first three modes reveal that the first two modes are mainly driven by local winds, with immediate effects of wind forcing and veering following Ekman effect. The first mode (37 % of total variability) is the response of meridional wind while the second mode (24 % of total variability) is linked primarily with zonal winds. The third and higher order modes are related to mesoscale circulation features. HFR derived surface transport presents a markedly seasonal variability being mostly southwards. Its comparison with Ekman-induced transport shows that wind contribution to the total surface transport is on average around 65 %.
A. Lana thanks the financial support from the CSIC-JAE doc program co-funded by the European Social Fund (ESF). J. Marmain is supported by Sur-Baleares Project. A. Orfila thanks the support from ENAP-Colombian Army through several grants. This work has been done thanks to the financial support from JERICO-NEXT project.
Databáze: OpenAIRE
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