Warmer than normal temperatures shown in red, cooler than normal temps shown in blue. The 1982-83 El Nino eventually reversed and developed into a weak La Nina pattern towards the end of 1983. Transition from El Nino to La Nina is also apparent in 1998. El Nino and La Nina events. This segment for the highlights global rainfall anomalies associated with the 1997-98 El Nino.
Green regions are wetter than normal and red regions are drier than normal.
The warm waters of El Nino produce heavier than normal precipitation in the eastern tropical Pacific and drier than normal conditions in the far western Pacific and Indonesia. During El Nino the upwelling of nutrients is suppressed with often times disastrous implications for marine ecosystems. The cooler upwelled nutrient-rich waters associated with the demise of El Nino and transition to La Nina initiated a huge plankton bloom along the equator. On regional scales, the SeaWiFS instrument documented the rapid demise of El Nino in the waters around the Galapagos Islands. The images show a explosion in plankton growth as the warm El Nino waters blamed for choking off essential ocean nutrients are replaced by deep cold upwelled waters.