Seminario: Wind and wave effects on surface currents in the Mediterranean Sea
Inici: 26/01/2021 09:00 - Fi: 26/01/2021 10:00Lloc: YouTube LIVE
Buenas tardes a tod@s,
El martes 26 de ENERO a las 10H00 va a llevarse a cabo un seminario interno impartido por Verónica Morales Márquez del IMEDEA con el título “Wind and wave effects on surface currents in the Mediterranean Sea”. Debido a la situación actual y para llegar a más público se hará una retransmisión online en directo del evento: https://www.youtube.com/user/ImedeaComDiv. Se va a habilitar la opción del chat en YouTube para animar la discusión y compilar las preguntas al ponente.
Información del Seminario:
TÍTULO: Wind and wave effects on surface currents in the Mediterranean Sea
PONENTE: Verónica Morales Márquez, Departamento de Oceanografía y Cambio Global, IMEDEA.
RESUMEN: Influence of wind and waves on the dynamics at the upper layer of the Mediterranean Sea is assessed using a modified Ekman model adding a Stokes-Coriolis force in the momentum equation. The methodology is applied to 25 years of waves and wind data from the ERA-Interim reanalysis product and altimetry data to generate mesoscale ageostrophic and geostrophic velocities. We found episodes where Ekman and Stokes currents significantly dominate the dynamics, modifying the geostrophic circulation, either by a vigorous input of momentum or for not being aligned to the geostrophic current direction (i.e. the Northern Current in the Gulf of Lions). A new regional classification of the Mediterranean Sea based on the wind and wave contribution to the total surface dynamics has been performed. We use an approach that combines the self-organizing maps (SOM) and the wavelet coherence analysis. We found that the effect of wind and waves is stronger over regions of the western basin and Gulf of Lion, while the eastern basin is mainly dominated by the geostrophic component. The resulting temporal variability patterns show that dominant frequencies between 1 and 5- 6 years arise from the combination of both geostrophy and ageostrophy components in the total currents velocity. Moreover, the long-term variability of regions dominated by Ekman-Stokes shows a characteristic time scale larger than 5 years for the whole basin that is anticorrelated with the North Atlantic Oscillation (NAO) and East Atlantic- Western Russia (EA/WR) patterns and with the positive one of East Atlantic (EA) and Scandinavia (SCAND) indices.