Global Weather Patterns

Convection The mixing motion of liquids or gases that are different temperatures Warm liquids or gases rise, while cool liquids or gases sink Happens because of the uneven heating of the earth (remember rotation and tilt of the earth) Causes wind in the atmosphere Causes currents in the ocean

Types of Winds Jet Stream Prevailing Westerlies Land or Sea Breezes

Jet Stream Fast flowing air found about 7.5 miles above the earth. Flows about 200 mph Forms between cold and warm air masses Constantly changes-dips and bends Flows west to east

Prevailing Westerlies Prevailing Westerlies winds in the Northern Hemisphere that are responsible for many of the weather movements across the United States and Canada. Move west to east across the United States

Sea Breeze During the day, land gets heated by the Sun much quicker than does water. As the land becomes warmer, it heats the air. This causes the air to expand, becoming less dense, and rise. Cooler air swoops in from the sea to replace the rising beach air. Cool air comes from the sea.

Land Breeze A land breeze occurs at night when the land cools faster than the sea. In this case, it is air above the warmer surface water that is heated and rises, pulling in air from the cooler land surface. Cool air comes from land.

Ocean Currents Gulf Stream El Nino La Nina

Gulf Stream Warm ocean current in the Atlantic Ocean Carries warm water from near the equator up to the North Atlantic Helps keep weather along the east coast mild by warming the air and land during winter

El Niño Unusual warming of waters in pacific Ocean. Ocean Currents are warmer than normal. Occurs ever 3 to 7 years Affects weather in North and South America/rains or droughts can occur-NC more rain in winter

La Niña Unusual cooling of waters in Pacific Ocean Occurs every 3 to 7 years Global climate patterns are opposite of those in El Niño.(Rain/Drought-NC will be drier)

Hurricanes (Tropical Cyclone) Powerful, low pressure storm that forms near the Equator and fueled by warm water Winds rotate counterclockwise around a central, calm eye. Winds of 75 mph or greater Huge amount of rain Low air pressure Thunder, lightning from cumulonimbus clouds Grows stronger when crosses the warm waters of the Gulf Stream Form off the coast of Africa and travels across the Atlantic Ocean that can impact east coast of the US.