Wind Why air moves Pressure Belts Moving air Wind is created by differences in air pressure  The greater the difference, the faster the wind moves  The difference in air pressure is generally caused by unequal heating of the earth  Pressure differences at the equator and the poles cause the air to move Wind does not move in one huge circular patter from the pole to the equator Smaller patterns called cells of rising and sinking air are present from the equator to the poles  There are every 30° in both hemispheres

Coriolis Effect Types of Winds The curving of moving objects by the Earth’s rotation  Northern Hemisphere: Curves to right  Southern Hemisphere: Curves to left  Example: sharpie on rotating balloon alizations/es1904/es1904page01.cfm Two main types  Local Winds  Global Winds

Trade Winds Westerlies The winds that blow from 30° latitude to the equator  Curving of the trade winds are caused by the Coriolis effect This is the type of wind that effects the weather in KS  Wind belts found in both Northern and Southern Hemispheres between 30°-60° latitude  Flow toward the poles in opposite direction of the trade winds  Helped early traders return to Europe

Polar Easterlies Jet Streams The wind belts that extend from the poles to 60° latitude in both hemispheres  Formed from cold, sinking air moving from poles to 60° N & S. Narrow belts of high-speed winds that blow in the upper troposphere and lower stratosphere  Often change speed and can reach a maximum speed of 500 mph  Do not follow regular path around the Earth  Controls the movement of storms  

Local Winds Sea and Land Breezes Winds influenced by the geography of an area  Mountain or ocean breezes can produce temperature differences that cause local winds During the day, the land heats up faster than the water. This heats the air above it, pulling the cool air toward land At night, the land cools faster than the water. This causes the cool air to flow out to the ocean.