Coming as the result of weakening trade winds over the tropical pacific, the result is heavy rains in some regions and zero rains in others. (chimalaya.org)
Every five years or so, weakening trade winds cause a shift to warmer than normal ocean temperatures in the eastern equatorial Pacific Ocean, a phenomena known as El Niño. (carbonbrief.org)
During an ENSO event, the prevailing trade winds weaken, reducing upwelling and altering ocean currents such that the sea surface temperatures warm, further weakening the trade winds. (climatehotmap.org)