How does the Southern Oscillation affect tropical climates?
The extent and depth of the tropical wet and dry climate regimes are dominated by two phases of El Nino Southern Oscillation (ENSO). During the El Nino (dry) stage, a current of warm water near Peru causes surface winds to move rain clouds away from Australia. If this persists, drought conditions may result. The system reverses during the anti-ENSO or La Nina stage, when warm waters near Australia cause surface air to converge. This results in heavy wet seasons for Queensland with the low-pressure phase making cyclones more likely. People living in the tropics may experience these overriding changes from El Nino to the anti-ENSO half a dozen times during their lifetimes.
