Oceanic layered microstructure and fronts

Abstract

This talk is divided into two parts: one deals with oceanic microstructure, with particular attention to the so-called "layered microstructure"; the other part is concerned with oceanic fronts. As an example of the latter I am going to describe in some detail a front east of Malta, which the Oceanography Group of this Centre is studying . The intention of giving this paper in this Ray Tracing Conference is to remind you that the vertical profiles of temperature and salinity, and hence speed of sound, are not a continuous and smooth curve as a function of depth, but rather consist of a large number of nearly homogeneous layers separated with interfacial regions where strong gradients with values as high as 0.5°C/10 cm are present . The reported work on the front east of Malta will show you that very high horizontal gradients of the oceanographical parameters, and hence sound speed,are established, with values as high as 6 m/s over a horizontal distance of 1 km, when passing through the frontal region.