Journal cover Journal topic
Ocean Science An interactive open-access journal of the European Geosciences Union
https://doi.org/10.5194/os-2018-14
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
Research article
20 Feb 2018
Review status
This discussion paper is a preprint. It is a manuscript under review for the journal Ocean Science (OS).
Dynamics of North Balearic Front during an autumn Tramontane and Mistral storm: air–sea coupling processes and stratification budget diagnostic
Léo Seyfried, Claude Estournel, Patrick Marsaleix, and Evelyne Richard Université de Toulouse, CNRS, UPS, Laboratoire d'Aérologie, Toulouse, France
Abstract. The north Balearic front forms the southern branch of the cyclonic gyre in the North Western Mediterranean Sea. Its dynamics exhibits significant seasonal variability. During autumn, the front spreads northward during the calm wind periods and rapidly moves back southward when it is exposed to strong northerly wind events such as the Tramontane and Mistral. These strong winds considerably enhance the air–sea exchanges. To investigate the role of air–sea exchanges on the dynamics of the North Balearic front, we used observations and a high-resolution air–sea coupled modelling system, and focused on a strong wind event observed in late October 2012, which was well-documented during the Hydrological Cycle Mediterranean Experiment. The coupled model was able to correctly reproduce the 4 °C sea surface temperature drop recorded in the frontal zone together with the observed southwestward displacement of the front. The comparison between the weak wind period preceding the event and the strong wind event itself highlighted the impact of the wind regime on the air–sea coupling, with both thermal and dynamical couplings during the low wind period and mainly thermal coupling during the strong wind period. The effect of air–sea exchanges on the stratification variations in the frontal zone was investigated with a stratification budget diagnosis. The stratification variations are controlled by diabatic air–sea buoyancy flux, adiabatic Ekman buoyancy flux, and advective processes. During the strong wind period, the Ekman buoyancy flux was found to be three times greater than the air–sea buoyancy flux and thus played a major role in the destratification of the frontal zone. The role of Ekman pumping and inertial wave on the advective processes is also discussed.
Citation: Seyfried, L., Estournel, C., Marsaleix, P., and Richard, E.: Dynamics of North Balearic Front during an autumn Tramontane and Mistral storm: air–sea coupling processes and stratification budget diagnostic, Ocean Sci. Discuss., https://doi.org/10.5194/os-2018-14, in review, 2018.
Léo Seyfried et al.
Léo Seyfried et al.
Léo Seyfried et al.

Viewed

Total article views: 309 (including HTML, PDF, and XML)

HTML PDF XML Total BibTeX EndNote
260 42 7 309 7 12

Views and downloads (calculated since 20 Feb 2018)

Cumulative views and downloads (calculated since 20 Feb 2018)

Viewed (geographical distribution)

Total article views: 309 (including HTML, PDF, and XML)

Thereof 309 with geography defined and 0 with unknown origin.

Country # Views %
  • 1

Saved

Discussed

Latest update: 19 Jun 2018
Publications Copernicus
Download
Share