OCEANIC CURRENTS IN THE SOUTHEASTERN OACIFIC OCEAN AS REVEALED BY SATELLITE ALTIMETRY DATA

Ten-days sea level anomalies (SLA) charts, based on the TOPEX/Poseidon (T/P) altimetry data for 1992-2003, as well as corresponding charts of sea surface dynamic heights (constructed by the superposition of SLA distributions over the climatic dynamic topography calculated from mean temperature and salinity data of WOA-1998 Atlas relative to 1000 m depth), were used to study main oceanic currents in the region 45-20°S, 110-70°W. Totally 377 T/P cycles for the period between 23 September 1992 and 25 February 2003 have been used for the analysis. Spatial and seasonal variability of the South Pacific Current has been investigated basing on the charts of dynamic heights gradients. The analysis allowed to distinguish zones with different degree of the current position variability, being minimal at 99°W where the current is most intense. Westward of 105°W the South Pacific Current may have bimodal structure and r.m.s. of its position may reach 3° of latitude. This is accompanied by a pronounced 35 T/P cycles peak (350 days) in its temporal variability. Eastward of 105°W there is no predominance in temporal variability of the current