Studied by 9 people
APES 2024
El Niño
Every 2-7 years, the interaction of the Earth’s atmosphere and ocean cause surface currents in the tropical Pacific Ocean to reverse direction
Normal year
Prevailing winds move East to West along the equator
High pressure in the East Pacific to low pressure in the West Pacific
Trade winds push warm surface waters away from the coast of South America towards the West Pacific
Wind pushes surface water west causing water to pile up in the West Pacific
Water near Indonesia can be 50 cm higher and 8 C warmer than near South America
Risk of coastal flooding in Pacific
Cold water rises up from dee causing nutrient rich upwellings along Peru & Ecuador
El Niño year
Decreased air pressure in the Eastern Pacific triggers El Niño
Winds weaken and warm water flows east towards South America
Supresses upwellings, shuts down the delivery of nutrients that support marine life and fisheries
Global weather patterns change: rainstorms, floods, droughts, and fires
Weather impacts: less rain, drought in Indonesia
More rain in South Eastern South America, Eastern Equatorial Africa, and Southern US: rainstorms and floods in areas that are usually dry ex. South California
Usually less hurricanes in the Atlantic and stronger hurricanes in the Central and Eastern Pacific Ocean
La Niña
The reversal of trade winds is stronger than usual, tends to follow El Niño year
La Niña year
Cold waters rise to the surface and extend west in equatorial Pacific
Winds blowing west strengthen
Occurs when sea surface temperatures in the central Pacific Ocean drop to lower than normal levels
Teh cooling of this area of water near the equator, which typically unfolds during late fall into early winter, yields impacts around the globe
Weather: drier in Southern US, colder and wetter in the Pacific
Less hurricanes in Souther and Eastern Pacific Ocean and more hurricanes in the Atlantic
El Niño year decreases
Income for anchovy fisheries in Peru and Ecuador
Note
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