EL NINO u El Nino an abnormal warming
EL NINO u El Nino, an abnormal warming of surface ocean waters in the eastern tropical Pacific, is one part of what's called the Southern Oscillation.
NORMAL YEAR u In a normal year, the trade winds blow westward and push warm surface water near Australia and New Guinea.
NORMAL YEAR u When warm water builds up in the western Pacific Ocean, nutrient-rich cold water comes up off the west coast of South America & fosters the growth of the fish population.
EL NINO YEAR • During an El Niño year, the trade winds weaken & warm, nutrient-poor water occupies the entire tropical Pacific Ocean.
EL NINO YEAR • Heavy rains that are tied to the warm water move into the central Pacific Ocean and cause drought in Indonesia and Australia.
u Normal u EL Year NINO Year
EL NINO u The Southern Oscillation is the see-saw pattern of reversing surface air pressure between the eastern and western tropical Pacific. u When the surface pressure is high in the eastern tropical Pacific it is low in the western tropical Pacific, and viceversa.
EL NINO u Because the ocean warming and pressure reversals are, for the most part, simultaneous, scientists call this phenomenon the El Nino/Southern Oscillation. u South American fisherman have given this phenomenon the name El Nino, which is Spanish for "The Christ Child, " " because it comes about the time of the celebration of the birth of the Christ Child at Christmas.
EL NINO u Scientists do not fully understand how El Nino forms. u It is believed that El Nino may have contributed to the 1993 Mississippi and 1995 California floods, drought conditions in South America, Africa and Australia.
EL NINO u It is also believed that El Nino contributed to the lack of serious storms such as hurricanes in the North Atlantic which spared states like Florida from serious storm related damage. u The goal is to provide sufficient warning so that we can be better prepared to deal with the damages and changes that El Nino causes in the weather.
- Slides: 10
