Science - Chapter 9

Important terms: humidity - the amount of water vapor in a given volume of air dew point - the temperature at which condensation begins cirrus - wispy, feathery clouds made of ice crystals that form at high levels cumulus - fluffy, white clouds, usually with flat bottoms, that look like a rounded pile of cotton stratus - clouds that form in flay layers and often cover much of the sky air mass - a huge body of air that has similar temperature, humidity, and air pressure at any given height front - the boundary where unlike air masses meet but do not mix jet stream - bands of high-speed winds about 10 kilometers above the earth’s surface hurricane - a tropical storm that has winds of about 119 kilometers per hour or higher Meteorologists - scientists who study the causes of weather and try to predict it isobar - a line on a weather map that joins places that have the same air pressure isotherm - a line on a weather map that joins places that have the same temperature \ Tiny particles of salt, dust, or smoke - what must be present for water \ Cirrus clouds - wispy feathery clouds Cirrus clouds - clouds made of ice crystals and indicate fair weather Stratus clouds - clouds that form in flat layers Stratus clouds - clouds that’s name is from the Latin word *strato* = spread out Stratus clouds - clouds that usually cover the sky (cloudy) Stratus clouds - As these clouds thicken they may produce drizzle, rain, or snow Cumulus clouds - clouds that look like cotton Cumulus clouds - these clouds when they’re short usually indicate fair weather Cumulus clouds - towering clouds with flat tops that often produce thunderstorms Altocumulus and altostratus - contain the prefix *alto* = high Altocumulus and altostratus - are “medium-level” clouds Altocumulus and altostratus - these clouds indicate precipitation Cirrocumulus - these clouds indicate a storm is on its way \ freezing rain, rain, snow, sleet, and hail - the types of precipitation freezing rain - sometimes falls as liquid water but freezes when they touch a cold surface rain - reaches earth as water snow - reaches the earth as frozen water sleet - sometimes snow that is melted or rain that refreezes as it falls hail - reaches earth as ice pellets \ Continental - overland Maritime - overwater tropical - close to the equator polar - near the poles arctic or antarctic - near colder region \ Cold front - cold air moves under warm air Warm front - warm air moves over cold Occulted front - warm front caught between 2 cold fronts Stationary front - when cold and warm fronts meet \ How a hurricane begins - a low-pressure area over warm water, or tropical disturbance what happens after there is a low-pressure area over warm water, or tropical disturbance - warm, humid air rises and begins to spiral What happens after warm, humid air rises and begins to spiral - as the air rises warmer, moist air is drawn into the system, and the hurricane gains energy what happens after moist air is drawn into the system and the hurricane gains energy - bands of high winds and heavy rains form as winds spiral inwards \ Cyclone - when the boundary between fronts meets and become distorted; can cause the air to swirl, creating a low-pressure center \ \