This research addressed a feasibility study for a remote monitoring system based on acoustic tomography to be used in antarctic regions. The analysis of data collected during PNRA oceanographic campaigns provided the environmental scenarios and the oceanographic processes to be successfully monitored by means of acoustic tomography and the appropriate information and data to initialize the tomographic processor. The case studies regarded High Salinity Shelf Water formation process in Terra Nova Bay polynya. The simplified but realistic environmental scenario considered a 1000 m deep area with a flat bottom. The dense water formation area was defined by a strong vertical salinity gradient in the surface, while in the areas outside, temperature and salinity were considered constant in depth leading to an almost linear increasing sound speed profile. At this stage of study, the possible presence of ice layer covering the area is not expected to have any significant effect on the propagation prediction, so it was not considered. Simulations were carried out with a beam model (Bellhop) which is well suited for active sonar modelling and ocean acoustic tomography in a range dependent environment. Each simulation involves the use of an acoustic source and a receiving station (tomographic pair) consisting of a vertical array of hydrophones. By measuring the travel time relative to different scenarios, the analysis aimed at understanding if the detection of the oceanographic phenomenon is feasible. In particular, the study aimed at determining the best compromise between acoustic frequencies, sensors number and geometrical configuration, in order to achieve the desired spatial-temporal resolution useful to detect the presence of dense water masses. An acoustic system configuration consisting of an acoustic source transmitting a pulse with a carrier frequency of 10 kHz, and of a receiving array made of 6 hydrophones resulted to be appropriate, while the minimum size of detectable Dense Water Mass is 0.5 km. In particular, the conducted sensitivity study evidences that the measure of travel time of acoustic rays can be successfully exploited to detect the presence of a dense water mass in a polynya area Acoustic tomography thus provides “images” of wide areas in the inner ocean for long periods and with an high temporal resolution; in addition it permits to reconstruct the sound speed field even in the upper layers where direct measurements cannot be performed as instruments are at risk of damage. It can then be consider a powerful mean of observation that well integrates conventional in situ measurements. Preliminar investigation on the applicability of this methodology in Terranova Bay polynya demonstrated that it is able to resolve the vertical structure of water column with a good precision.

The project aims to determine the mass balance components in the Dome C drainage area and to study and monitor local glaciers in Victoria Land. The goal is to define the mass balance of the ice cap through the analysis of its altimetric variation with satellite systems and through the determination of the values of the positive (snow accumulation) and negative (flow of glaciers to the anchor line) components of the balance mass. Trought the study of the snow cores (collected as part of the ITASE project (XVII/XVIII expedition)), was determined the annual stratigraphy and evaluated the snow accumulation, the isotopic temperature and the chemical composition of the snow cores. Moreover analysis of geophysical data (GPR, GPS, RES, spectroradiometry) and remote sensing data were carried out for the study of the variability of snow accumulation, of the dynamics of the ice cap and of the flow of glaciers to the anchor line.