Fronts and Mesoscale Variability in the Southern Indian Ocean as Inferred from the TOPEX/Poseidon and ERS-2 Altimetry Data

Charts of sea level anomalies (SLA) based on the combined altimetry data from the TOPEX/Posidon and ERS-2 satellites, as well as the corresponding charts of the sea surface dynamic heights (constructed by the superposition of SLA distributions over the climatic dynamic topography) and the temperature gradients at the ocean surface on the basis of the satellite Multi-Channel Sea Surface Temperature (MCSST) data, were used to study the mesoscale variability related to the fronts in the Southern Indian Ocean (30--60S, 20--150E). An analysis of these three types of satellite information for the central weeks of each month during the period from 1997 to 1999 allowed us to distinguish zones of enhanced meandering (eddy formation) within the basin under study, as well as the contributions of individual fronts and their interaction to the regional mesoscale variability. The problems of the correlation between the intensity of mesoscale variability and peculiarities of the local bottom topography and seasonal/interannual variability of mesoscale dynamics are addressed.