Active and passive acoustics for in-situ observations of the ocean status

Recent European policies underlined the need to improve integration between methods and platforms used for ocean monitoring in order to overcome the disadvantages of each type of instruments and to emphasize their complementarity. Indeed, the development of methodologies for the full use of all information that can be extracted from existing measurement systems represents a promising frontier for improving the knowledge of the ocean. In particular, the use of instruments installed on moorings or floats able to listen to ambient noise could contribute to enhance the monitoring capacity of meteorological phenomena also in open ocean without the need of fixed platforms. Oceanic ambient noise measurements can be analyzed to obtain qualitative and even quantitative information about meteorological phenomena whilst backscatter echoes can describe biological activities. The paper explores the potentiality of available acoustic data analyzing long time series of acoustic measurements acquired in the North-Western Mediterranean Sea and in Tethys Bay (Antarctica).