Page 1 : - ENSO a, , ‘+ Changes in the pressure conditions over the southern oceans also affect the monsoons,, , + Normally when the tropical eastern south Pacific Ocean experiences high pressure, the tropical eastern, Indian Ocean experiences low pressure., , * But in certain years, there is a reversal in the pressure conditions and the eastern Pacific has lower, pressure in comparison to the eastern Indian Ocean. This periodic change in pressure conditions is, known as the Southern Oscillation or SO., , + The difference in pressure over Tahiti (Pacific Ocean, 18°S/149°W) and Darwin in northern Australia, (Indian Ocean, 12°30'S/131°E) is computed to predict the intensity of the monsoons, , + If the pressure differences were negative, it would mean below average and late monsoons., , + A feature connected with the SO is the El Nino phenomenon in which a warm ocean current that, flows past the Peruvian Coast, in place of the cold Peruvian current, every 2 to 5 years., , ‘+ The changes in pressure conditions are connected to the El Nino., , "Hence, the phenomenon is referred to as ENSO[EI Nino Southern Oscillations)., , & OF Ques, JZ, —S, , , , , , , , , , wT “ Inter Tropical Convergence Zone, > ‘The Inter Tropical Convergence Zone (ITCZ,) is a Y, broad trough of low pressure in equatorial, v latitudes. This is where the northeast and the, , southeast trade winds converge. This, convergence zone lies more or less parallel to, the equator but moves north or south with the, apparent movement of the sun,, , , , El Nino: This is a name given to the periodic, , development ofa warm ocean current along the, , coast of Pert as a temporary replacement of the, , cold Peruvian current. ‘ElNino'is a Spanish word, , meaning ‘the child’, and refers to the baby Christ,, , as this current starts flowing during Christmas., , ‘The presence of the El. Nino leads to an increase, , in sea-surface temperatures and weakening of o, the trade winds in the region., , oak)