Temporal Variability of Currents in the Ross Sea (Antarctica)

Abstract

Some results from the analysis of about one year long time series of currents, tem­perature and salinity data collected in the central-western part of the Ross Sea during 1995 are here presented. Temporal evolution and seasonal variability of currents at intermediate and deep layers in different locations are described. The role of surface seasonal processes and of the advection of different water masses on temperature and salinity variations is investigated. Spectral analysis, focusing on low frequency oscillations, evidences that kinetic energy is mainly concentrat­ed on mesoscale phenomena time scale at which barotropic movements prevail. At higher frequencies, the tidal component strongly dominates, while the inertial oscillation, whose frequency is the same band, is less important. The ice forma­tion and melting processes affect also the intermediate level as evidenced in tem­perature and salinity time series, but do not seem to modify significantly the cir­culation in this layer. Apart from a weakeness in kinetic energy observed in most of the locations from late April to early June, the general circulation does not pre­sent an important seasonal variability, suggesting that the open ocean Antarctic Circumpolar Current acts as a prevailing forcing with respect to the thermoaline forcings.