El Niño as a consequence of the global oscillation in the dynamics of the earth’s climatic system

Abstract

During study of the physical nature and potential precursor features of the El Nino phenomenon in the Pacific, it was found that a negative large-scale temperature anomaly on the Indian Ocean surface may be one of its significant precursors. This anomaly appears prior to the occurrence of El Nino and is accompanied by growth in atmospheric pressure. It gradually extends eastwards along the equator until the zone of planetary convection in the area of the Indonesian Region. The west wind that emerges on the eastern peripherals of the mentioned pressure anomaly leads to reversal of the Pacific segment of the Walker equatorial atmospheric circulation and to a subsequent change in the zonal thermal dipole polarity in the tropical zone of the Pacific (the latter means culmination of the El Nino phenomenon). In addition to the mentioned thermobaric anomaly in the Indian Ocean, other obvious signs of large-scale pressure anomalies have been found in the global atmospheric pressure field; these anomalies may be interpreted as manifestations of the intradecadal global oscillation in the dynamics of the modern climatic system. It is suggested that the whole known complex of events related to the El Nino phenomenon in the Pacific is a consequence and a regional link of the planetary structure of this global atmospheric phenomenon.