Chapter 4 Section 3 Air Movement

Atmospheric Pressure and Winds What is wind? Wind is moving air. Created by differences in air pressure Because air moves from areas of high pressure to areas of low pressure, winds generally move from the poles to the equator. The curving of moving objects, such as wind, by the Earth’s rotation is called the Coriolis Effect

Types of Winds What are the 2 main types of winds? Local winds and Global Winds Local Winds generally move short distances and can blow from any direction. Global Winds are part of a pattern of air circulation that moves across the Earth

Types of Winds In both hemispheres, the winds that blow from 30 degrees latitude to the equator are called trade winds. The westerlies are winds belts found in both the Northern and Southern Hemispheres between 30 degrees and 60 degrees latitude.

Types of Winds The Polar easterlies are winds belts that extend from the poles to 60 degrees latitude in both hemispheres. The Jet Streams are narrow belts of high-speed winds that blow in the upper troposphere and lower stratosphere.

Chapter 4 Section 3 Questions……. What causes land and sea breezes? The fact that the land heats and cools more quickly than water. Which wind system is responsible for the movement of much of the weather across the U.S. and Canada? Prevailing Westerlies When cool, dense air from over the water flows inland it’s called a _________________. Sea Breeze What is the windless zone at the equator called? The Doldrums

Chapter 4 Section 3 Questions………. The air above the _________ rises b/c it has low density and low pressure. Equator Why is the air above the equator heated more than at any other place on Earth? Because solar rays strike the equator more directly. What is destroying ozone molecules therefore destroying the ozone layer? “CFC’s “ or Chlorofluorocarbons Where is air pressure the greatest? At Sea Level Define Sea Breeze When cool, dense air over the water flows inland.