How does ENSO work?
Peru and Indonesia are two countries that lie on either side of the Pacific Ocean. Peru is to the East of the ocean in South America and Indonesia is an island to the west of the Pacific ocean. Normally, Indonesia is very wet while Peru is hot and dry. ENSO begins when ocean currents from the far south decrease so that there is very little cold water pushed up along side of Peru. The water in Peru gets much warmer weakening the North-East trade winds that normally blow from Peru towards Indonesia. When the trade winds weaken, the up-lifting air current that normally rises over Indonesia bringing rain shifts towards Peru. For this reason, Peru becomes very wet and Indonesia becomes suddenly much drier. The climates of the two countries change!
