The use of integrated circulation index for the description of synoptic situations in the Pacific Ocean tropics during El Niño-Southern Oscillation extreme events

Abstract

The potential of Petrosyants-Gushchina integrated circulation index in respect to the problem of synoptic analysis in low latitudes is considered. The compositional models of synoptic situations, which led to the formation of extreme conditions in weather and climate over the Pacific Ocean, are constructed using the computed indices according to the data of NCEP/NCAR reanalysis for 1950-2002 separately for El Niño and La Niña events. It is demonstrated that the barometric circulation pattern of synoptic processes in tropics, being reproduced using indices, indicates the main peculiarities of atmospheric circulation in low latitudes and can be the quantitative indicator of the whole circulation system of El Niño-Southern Oscillation over the Pacific Ocean.