General Studies Mains | Paper-1| World Geography | Salient Features Of Physical Geography | Climate | Enso (El Niño Southern Oscillation) with K. SIDDHARTHA
El Niño conditions occur when abnormally warm waters accumulate in tropical latitudes of the central and eastern Pacific Ocean. Consequently, tropical rains that usually fall over Indonesia shift eastward.
This periodic appearance of warm water is referred to as El Nino (the christ child) because it usually occurs around Christmas time) and it causes unusual warming. The unusual outbreak of warm water comes from Western Pacific in the along Equatorial. This appearance causes the air pressure to drop over large areas of the southeast Pacific while pressure rises over western Pacific. This seesaw variation of air pressure is called the southern oscillation.
In the late 1960s that Jacob Bjerknes and others realized that the changes in the ocean and the atmosphere were connected and the hybrid term “ENSO” was developed.