The Peruvian atmospheric jet stream: Synoptic mechanism and variability reasons

The most frequently observed (classic) scenario and two types of deviations from it are revealed using the data of the analysis of synoptic situations accompanying the formation of the Peruvian jet stream (JS). It is established that the movement of the Peruvian High (the eastern part of the South Pacific High divided into two high-pressure zones) is of the key importance for the formation of the Peruvian JS. Determined is the relationship between the formation of the Peruvian JS and the disruption of the circulation in the Hadley cell in the eastern Pacific. Derived is the dependence of the synoptic mechanism of the Peruvian JS formation in the years with two different types of El Niño, when the Peruvian High formation due to the weakening of the South Pacific High often causes the final anticyclone of the cyclonic series in the mid-latitudes of the Southern Hemisphere. The regression analysis demonstrated the existence of the complex nonlinear relationship between the Peruvian JS formation and the Madden-Julian Oscillation through the impact on the pressure field.