Investigation of the oceanic currents and fronts in the Southeastern Pacific Ocean using satellite altimetry data
Alexander Sirota(1) and Sergey Lebedev(2)
5, Dm.Donskoy Str.,
(2) Geophisical Center Russian Academy of Sciense, 3 Molodezhnaya Str., 117236 Moscow, Russian Federation
Sea level anomalies (SLA) charts, based on the merged TOPEX/Poseidon and ERS-2 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 and fronts in the region 45-20°S, 110-70°W. Spatial and temporal variability of the South Pacific Current, Peru/Chile Current, Subtropical Front has been investigated basing on the charts of dynamic heights gradients, calculated maps of occurrence of mesoscale features (e.g., frontal eddies) and calculated geostrophic current velocities. The analysis allowed to distinguish zones with different degree of the currents position and intensity variability. The main features of the seasonal and temporal variability of the currents and front were revealed.
This study has demonstrated efficiency of the analysis of the satellite altimetry data in the investigation of the structure and spatial and temporal variability of the main surface currents and oceanic fronts in the Southeastern Pacific. In view of the fact of the lack of regular oceanographic observations in the Southeastern Pacific the proposed approach may give a high advantage and improve our knowledge about seasonal and interannual variability of the currents and fronts in this region.
This work was partly supported by the Russian Fund of Basic Research, Grant No. 06-05-65061-a.