| ABSTRACT | The North Western Mediterranean Sea is a well-known place where deep water formation (DWF) events occur, sustaining the Mediterranean overturning circulation. Thus, it is fundamental to monitor, study and understand its hydrodynamics to be able to assess and forecast the impact that these processes have on the climate change.
Here we focus on the Ligurian Sea in the north-eastern part of the Western Mediterranean, that is occasionally involved in DWF events.
This work aims to present some preliminary results of the analysis of an historical dataset of CTD profiles from the 1976 to 2014. A box centered in the Ligurian Sea is considered, defined by the Corsica Channel to the south-east and the Nice-Calvì transects to the west. Geostrophic calculations have been carried out, focusing on the circulation patterns, that are subject of both seasonal and interannual variability (Astraldi et al, 1994) and quantifying the transiting water masses. We consider the Levantine Intermediate Water (LIW), a fraction of which flows out of the Tyrrhenian northwards and enters the Ligurian Sea and Provençal Basin and becomes the preconditioning agent in the DWF in the Gulf of Lions (Tanhua et al. 2013), the Atlantic Water (AW) and also the Western Mediterranean Deep Water (WMDW).
Part of the dataset was accessible thanks to the MEDATLAS project. More specifically from MEDATLAS we consider the following cruises: EAA2 (August 1976, June 1976, December 1979, November 1981, October 1982), DYOME I (July 1981), DYOME II (February 1982) , EALP (March 1982), EATY (September 1985, December 1986, November 1987, February 1988, June 1989), MAD-0792 (July 1992). The dataset has been integrated also with more recent cruises: Sirena06 (July 2006), MEDOCC07 (October 2007), Sesame-IT4 (March 2008), Eurofleets11 (May 2011), Eurofleets12 (November 2012), Venus2 (June 2013), Ichnussa13 (October 2013), MEDOCC14 (March 2014).
A 20 year long time series from an Acoustic Doppler Current Profiler (ADCP) mounted in the mooring in the Corsica Channel is also available and useful to quantify the time variability of the inflow from the Tyrrhenian Sea into the Ligurian Sea. Data from the mooring has been used to choose more carefully the level of no motion for the geostrophic calculations. |