La Nina
  • Pacific temperature cooler than normal
  • Last 9-12 months
  • The Pacific Ocean drops 3-5 degrees
  • Reoccurs every 3-7 years
  • Cause by a decrease in ocean temp and increase in trade wind strength
  • The westward wind gets stronger
  • Allowing low cooler water to surface toward South America
  • Cloud build up in Southeast Asia
  • The wet period in the middle eastern U.S
  • Drought in South-eastern U.S
  • Flood in Australia
  • Brings nutrients to the South American coast
  • Cooler and snowier Canadian winter
  • Up welling of cool water


El Nino
  • Warm ocean current flow along the equator
  • Occur every 4-7 years
  • Trade wind weakens during El Nino
  • Water flows downhill to the east
  • Less warm air rises in the west
  • As a result, less wind is created
  • Wind can no longer push warm water from the coast of South America
  • Warm water pushes cooler, unwilling water
  • No upwelling
to fertilize phytoplankton El Niño produces a lot of evaporation More cloud build-up
  • in South America



author avatar
William Anderson (Schoolworkhelper Editorial Team)
William completed his Bachelor of Science and Master of Arts in 2013. He current serves as a lecturer, tutor and freelance writer. In his spare time, he enjoys reading, walking his dog and parasailing. Article last reviewed: 2022 | St. Rosemary Institution © 2010-2024 | Creative Commons 4.0

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