Tuesday, February 21, 2012

Thursday: El Niño & La Niña



El Niño:

El Niño is a disruption of the ocean atmospheric system that causes global changes in weather, mostly oceanic warming. It occurs every 3 to 7 years and can last anywhere from 12 to18 months. El Niño appears with Southern Oscillation and is seen in wintertime. El Niño brings warmer than normal weather.


La Niña:


La Niña is sometimes referred to as El Viejo. It is associated with cooler weather and occurs anytime El Niño is not present.


Wednesday: Upwelling & Downwelling



Upwelling:
The transport of water to deeper levels.

Upwelling occurs when surface waters diverge. Upwelling brings water to the surface. Many ocean animals live where upwelling occurs because it also brings nutrients to the surface.


Downwelling:

A downward current of surface water in the ocean

Downwelling is basically a convergent boundary in the ocean. It occurs when surface waters converge. Downwelling allows animals to live in the deep ocean because it brings oxygen down.

Tuesday: Tornadoes



Tornadoes are rapidly rotating columns of air driven by energy in the atmosphere. Tornadoes are formed through intense thunderstorms. Wind speeds can be up to 318 mph. The diameter of a tornado can be anywhere from a few feet to a mile. The winds normally travel northwest. The storm travels at 20-60 mph. It can last from a few minutes to minutes. When caught in a tornado seek shelter under a sturdy object, away from windows.


Monday: Hurricanes





Hurricanes are large tropical storms with heavy wind. Wind speeds in a hurricane can be 74 mph or greater. Hurricanes begin as tropical storms, but gain strength through warm water. A hurricane can cause flooding, tornadoes, and storm surges, which can be deadly. Each storm has a diameter from 25 to 600 miles wide. The storm lasts a week on average. Hurricanes are named from a list chosen by the World Meteorolgical Organization.







Hurricane Safety:



  • Listen to radio


  • Check disaster supplies (replace/restock)


  • Close windows, doors, hurricane shutters


  • Fill cars with gas


  • Create evacuation plan


  • Have water & non-perishable food


  • Have flashlight, radio, first-ad kits, medications, extra cash, & maps of the area