Assessment of hydrodynamics, biochemical parameters and eddy diffusivity in a semi-enclosed Ionian basin. (November 2016)

• Record Type: Journal Article
• Authors: De Serio, Francesca; Mossa, Michele
• Is Part Of: Deep sea research. Volume 133(2016)
• Page Start: 176
• Page End: 185
• Publication Date: 2016-11
• Subjects: Monitoring -- Water quality indicators -- Turbulent parameters -- Eddy diffusivity -- Crude oil; Oceanography -- Periodicals; Ocean bottom -- Periodicals; Marine biology -- Periodicals; 551.46
• DOI: 10.1016/j.dsr2.2016.04.001
• Languages: English
• ISSNs: 0967-0645

Abstract

Abstract: In the framework of the Italian flagship Project RITMARE, during December 2013 a meteo-oceanographic station was installed in the Mar Grande basin, a semi-enclosed bay in Southern Italy, connected to the Ionian Sea. Due to the presence of coastal heavy industry and anthropic pressure, this marine system has experienced environmental degradation over the last decades. Therefore, much monitoring of hydrodynamics and water quality indicators is required. In fact, this monitoring makes it possible to check the real-time biochemical status of the basin and therefore promptly intervene when accidental spills occur, and to create a dataset necessary to calibrate and validate modelling systems providing forecasts. The present paper aims to analyze and discuss the long term and continuous recordings of hydrodynamic and biochemical data collected by this station, available for the period from January 2014 up to December 2014. In detail, hourly measurements of wind, waves, current velocity, water temperature, salinity, chlorophyll and turbidity concentrations were archived in monthly time-series and processed in frequency domain, using the FFT (Fast Fourier Transform), to both delineate the reciprocal effects of drivers and deduce some correlations between parameters (De Serio and Mossa, 2013 ). Following this, monthly surface current data were processed in order to obtain time-averaged values of the turbulent velocity components, turbulent kinetic energy and turbulent time scales. Based on these calculated turbulent parameters, the horizontal eddy diffusivity was computed with the hypothesis of homogeneous turbulence using two methods, which provided results with the same order of magnitude. These results are of interest for numerical dispersion models. Finally, only referring to the month of December 2014, the time series of the crude oil concentration was available at the station and was examined in depth. The field data enabled us to conclude that the crude oil dispersion process is influenced by the sea turbulence.