Transcript El Nino - Cloudfront.net

El Nino
El Nino
A ocean/weather phenomenon that creates
changes weather patterns.
Traditional name , El Nino, comes from south
America where the changes is most notable, and
it happens around Christmas (if the changes
happens that year!)
True name now is ENSO , El Nino Southern
Occilation.
To understand El Nino
1) Understand Thermoclines
2) Understand the link between hot ocean
water, convection and rain!
1) thermocline
2) Connection between hot ocean
water, convection & rain!
Typical Ocean currents (gyres)
Normal vs. El Nino
• Normal – strong
trade winds
• El nino – trade
winds slow down or
stop
Normal
•
Prentice Hall Textbook animation link
El Nino: El Nino Development
La Nina… think, el nino opposite!
•
Prentice Hall Textbook animation link
El Nino
El Nino / La Nina in the thermocline
Prediction of El Nino
• Satellites
– provide data on tropical rainfall, wind, and
ocean temperature patterns, as well as
changes in conditions for hurricane formation.
• Ocean buoys
– help to monitor sea-surface and upper ocean
temperatures.
• Super computers
– gather all of the weather data around the
world and put it into useful formats used by
scientists.
– Run models for future change
El Nino Years:
The first signs of an El Niño are:
• Warm water spreads back from the west Pacific
to the east Pacific
• Warm air rises near Peru (low pressure),
causing rain in the Americas
• Decrease in air pressure over central and
eastern Pacific Ocean
• Winds in the Pacific ocean weaken or stop all
together!
• Net result is drought in the Asia and rainfall in
the Americas.
La Nina Years:
The first signs of an La Nina are:
• Warm water moves back to the west Pacific from
the east Pacific
• Warm air rises near Asia (low pressure), causing
rain in Indonesia and north Australia.
• Decrease in air pressure in Asia, Australia, etc
• Winds in the Pacific ocean increase
dramatically!
• Net result is drought in the Americas and rainfall
in Asia.