EVERYDAY SCIENCE

Detailed explanation-1: -El Niño causes the Pacific jet stream to move south and spread further east. During winter, this leads to wetter conditions than usual in the Southern U.S. and warmer and drier conditions in the North.

Detailed explanation-2: -An El Niño condition occurs when surface water in the equatorial Pacific becomes warmer than average and east winds blow weaker than normal. The opposite condition is called La Niña. During this phase of ENSO, the water is cooler than normal and the east winds are stronger. El Niños typically occur every 3 to 5 years.

Detailed explanation-3: -The SST, in turn, affects the wind distribution: near the equator surface air converges towards the warmer water. As the warm water spreads towards the central and eastern equatorial Pacific during an El Niño event, convection, low-level convergence and weakened trade winds follow.

Detailed explanation-4: -During El Niño, the surface winds across the entire tropical Pacific are weaker than usual. Ocean temperatures in the central and eastern tropical Pacific Ocean are warmer than average, and rainfall is below average over Indonesia and above average over the central or eastern Pacific.