WIND The horizontal movement of air from an area of high pressure to an area of low pressure

What causes Winds? Differences in air pressure Heating of the air , decreases pressure. Warm air rises creating a low pressure Cool air rushes in to replace the warm air. Cooler, dense air produces a high pressure As air goes from high to low pressure, winds form

MEASURING WINDS Described by direction & speed The name of a wind tells where it is coming from Wind speed is measured with a anemometer Wind-chill factor is the increased cooling that a wind can cause

LOCAL WINDS Blow over short distances Caused by unequal heating of the Earth’s surface within a small area Two types Sea Breezes: winds that blow from a body of water onto land Land Breezes: winds that blow from land to a body of water

LOCAL WINDS

GLOBAL WINDS Winds that blow steadily from specific directions over long distances Created by unequal heating of the Earth’s surface Produced by the movement of air pressure between the equator and the North & South Poles Coriolis Effect: the way Earth’s rotation makes winds curve Northern Hemisphere: winds curve to the right Southern Hemisphere: winds curve to the left

CORIOLIS EFFECT

GLOBAL WIND BELTS Doldrums: regions near the equator with little or no winds. Calm and weak Trade Winds: warm air rising from the equator cools and sinks. Located between 30°N & S of equator. Calm, few clouds, little rain fall Prevailing Westerlies: located in the belt from 30-60° latitude in both hemispheres. Strong winds. Impacts US weather Polar Easterlies: cooling takes place between 50-60° latitude as approaching the poles. Cold, weak winds. Impacts US weather

GLOBAL WINDS

JET STREAMS Bands of high-speed winds about 10 km above Earth’s surface (upper Troposphere) Blow from west to east at speeds of 200-400 km/hr Help to move storms Referred to as head or tail winds (flight)

GLOBAL WINDS Create an Acrostic Poem using Global Winds