El Nino La Nina

El Nino and La Nina


El Nino & La Nina

El Nino and La Nina result from changes in the circulation, air pressure and weather patterns in the Pacific ocean, they are part of a continually oscillating climate pattern pattern called the El Nino Southern Oscillation. 

Normal conditions- trade winds move warm water towards the western Pacific

El Nino conditions - east to west trade winds disrupted, water sloshes eastwards, air pressure over wast coast of South America becomes unusually low

La Nina conditions - The easterly trade winds are more intense than normal, air pressure is unusually high over the west coast of South America

(high pressure = hot and dry, low pressure = humid and wet)

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El Nino & La Nina effects

El Nino 

Peru (floods, fires, drought, famine) - 3 years of normal rainfall in three months, infrastructure destroyed - 30 major bridges lost, 370 miles of road destroyed, wildlife patterns destroyed, 250 deaths, thousands evacuated, 350,000 homeless, economy stopped

Also effected California (droughts, forest fires) Mississippi (snow) North America (tornadoes) Mexico (hurricanes, floods)

La Nina 

Carribean and North America (hurricanes) - Oct 1998, Hurricane George, destroyed infrastructure, created mudslides, more than 300 people died, 100,000 left homeless

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