COMMON ATMOSPHERIC PHENOMENA Why the wind blows? Why monsoons occur? What is the so-called Intertropical Convergence Zone? What happens when air is heated? What Makes the Air Move? WINDS - Are air that is moving horizontally. - Are caused by differences in air pressure. AIR MOVES TOWARD THE PLACE WHERE WARM AIR IS RISING. LOCAL WIND --a wind that blows over a short distance. --caused by the UNEQUAL heating of Earth’s surface within a small region. Example: Sea breeze Land breeze Which warms up faster? Land or Water? SEA BREEZE During the day, the land heats up faster than the water in the sea. LAND BREEZE During the night, the land and sea will both cool down. But the land will lose heat faster than the water in the sea. GLOBAL WIND --Winds that blow over long distances from a specific direction. --caused by the UNEQUAL heating of Earth’s surface across a large region. Examples: Trade winds Westerlies Polar Easterlies GLOBAL WIND 1. TRADE WINDS --are wind belts just north and south of the equator. In the Northern Hemisphere, they blow from northeast to the southwest. 2. WESTERLIES --the prevailing westerlies occur between 30º and 60º latitude in both hemisphere. These winds generally blow from west to east over much of North America. 3. POLAR EATERLIES --extend from 60º latitude to the poles in both hemispheres. Why monsoons occur? MONSOON --is wind system that is characterized by seasonal reversal of direction. MONSOON 1. AMIHAN (Northeast Monsoon) --comes from northeast and moves toward the south. 2. HABAGAT (Southwest Monsoon) --comes from southwest and moves toward the north. What is the so-called Intertropical Convergence Zone (ITCZ)? Intertropical Convergence Zone (ITCZ) Intertropical Convergence Zone (ITCZ) --is the place where winds in the tropics meet or converge. Intertropical Convergence Zone (ITCZ) In the time rising warm air will form clouds, which may lead to thunderstorms. THANK YOU!