What are some of the worldwide weather changes that result from el nino?
El Nino changes the distribution of rainfall causing floods in some areas and drought in other areas.It increases the rainfall over the tropical eastern Pacific ocean and decreases over the western Pacific ocean.This is due to the warming(more than the normal) of the eastern Pacific ocean.Monthly or seasonal fluctuations occurs in the difference of air pressures in Darwin and Tahiti.On the whole,weather and climate around the world (particularly the Southern Hemisphere)are affected . Increasing bush fires and increasing haze conditions are noticed in parts of Northern Australia and in South-east Asia.More sea ice is found west of Antarctic peninsula during this period.In North America,winters are warmer than normal.Less hurricane activity is noticed(south of 25 degree N latitude)in the Atlantic ocean.US Pacific coast experiences more wave-activity resulting in erosion of coasts.Eastern Brazil becomes cooler and drier.East Africa experiences long rains particularly during March to May.
Good qestion and here is the scientific answer you are looking for. When non El Nino conditions exist we find a high pressure ridge over the eastern Pacific Ocean and lower pressures over Indonesia. This gives us the typical easterlies along the equator. This condition is accompanied by upwelling and cooler ocean water in the eastern Pacific with warmer water in the western Pacific. The trades are the lower extent of what is called the Walker circulation – rising air and heavy rain over the western Pacific and sinking dry air over the eastern Pacific. When this condition I have just described in very strong an exceptionaly cool eastern Pacific is referred to as a La Nina event. The name means “the girl child”. When the high pressure ridge over the eastern Pacific weakens and the low pressure over the western Pacific is replaced by high pressure the easterlies are weakended and basically replaced by westerlies. This carries warm water eastward and the Walker circulation is reversed with
