| Term | Definition |
|---|
| wind | the movement of air from one place to another caused by differences in air pressure due to the unequal heating of the Earth's surface-named by where they came from, two major types |
| local winds | blow from any direction over short distances-3 kinds: monsoon, land breeze, sea breeze |
| sea breeze | they blow during the day from water |
| land breeze | blows from the land at night |
| monsoon | seasonal winds that bring either heavy rain or dry winds especially in Asia |
| global winds | winds that cover large areas and blow in specific directions-3 kinds: doldrums, prevailing westerlies, jet stream |
| doldrums | 0° latitude (equator): winds are very calm; problem for sailboats |
| prevailing westerlies | strong winds; we live here |
| jet stream | fastest winds; highest winds; go from west to east ("we-e-e-e") |
| coriolis effect | the Earth's rotation causes winds to curve in specific directions |
| wind vane | instrument that tells you wind direction |
| anemometer | an instrument that tells you wind speed |
| evaporation | process by which water changes from a liquid to gas. Heat is necessary. If the air is hot & dry,there is more evaporation. This water in the air is called water vapor. |
| condensation | process by which water vapor turns into a liquid when it touches a cold surface. Clouds are formed when water vapor condenses on cold dust particles. Glasses filled with ice liquids "sweat". |
| dew point | the temperature at which water will condense on a cold surface. |
| wind chill factor | the increased cooling that wind can cause b/c it speeds up evaporation |
| precipitation | forms of water that fall through the atmosphere. Water vapor condenses on cold dust particles to form cloud droplets. These droplets combine to form raindrops. When they get too heavy, gravity pulls them to the Earth as rain, snow, hail, sleet. |
| 1 inch of rain | 10 inches of snow |
| rain gauge | measures rainfall in inches |
| humidity | water vapor in the air |
| relative humidity | the % of moisture the air holds compared to the amount it can hold at a given temperature |
| psychrometer | instrument that can measure the amount of moisture in the air (relative humidity) |
| saturated | when the relative humidity is 100% the air is __________. It is holding all of the water vapor it can at that temperature. Warm air can hold more water vapor. Cold air can hold less. |
| air mass | large bodies of air that cause changes in weather. They can cover thousands of square miles.-identified by two characteristics: humidity, temperature-4 types: maritime tropical and polar, and continental tropical and polar |
| maritime tropical | wet & warm, forms over water |
| maritime polar | wet & cold, forms over water |
| continental tropical | dry & warm, forms over land |
| continental polar | dry & cold, forms over land |
| front | area where air masses meet, do not mix and cause stormy, changeable weather-4 kinds: cold, warm, stationary |
| cold front | moves quickly violent thunderstorms and then clear, cool temperatures |
| warm front | moves slowly, rain or snow, warm & humid |
| stationary front | warm & cold front meet, no movement, many days of clouds and precipitation |
| storm | a violent disturbance in the atmosphere. caused when there are sudden changes in air pressure and rapid air movement. The can cover large OR small areas. |
| tornadoes | whirling, funnel-shaped winds that develop in low, heavy cumulonimbus cloud |
| hurricanes | powerful cyclone whose winds move counter-clockwise |
| storm surge | huge dome of water that floods coast |
Combine with other sets
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