| A | B |
|---|
| wind | The horizontal movement of air from an area of high pressure to an area of lower pressure. |
| anemometer | An instrument used to measure wind speed. |
| wind-chill factor | Increased cooling caused by the wind. |
| local winds | Winds that blow over short distances. |
| sea breeze | The flow of air from an ocean or lake to the land. |
| land breeze | The flow of air from land to a body of water. |
| monsoons | Sea and land breezes over a large region that change directions with the seasons. |
| global winds | Winds that blow steadily from specific directions over long distances. |
| Coriolis effect | The way Earth's rotation makes winds in the Northern Hemisphere curve to the right and winds in the Southern Hemisphere curve to the left. |
| jet streams | Bands of high-speed winds about 10 kilometers above Earth's surface. |
| evaporation | The process by which water molecules in liquid water escape into the air as water vapor. |
| humidity | A measure of the amount of water vapor in the air. |
| relative humidity | The percentage of water vapor in the air compared to the maximum amount the air can hold at that temperature. |
| psychrometer | An instrument used to measure relative humidity, consisiting of a wet-bulb thermometer and a dry-bulb thermometer. |
| condensation | The process by which molecules of water vapor in the air become liquid water. |
| dew point | The temperature at which condensation begins. |
| cumulus | Clouds that form less than 2 kilometers above the ground and look like fluffy, rounded piles of cotton. |
| stratus | Clouds that form in flat layers. |
| cirrus | Wispy, feathery clouds made mostly of ice crystals that form at high levels, above about 6 kilometers. |
| precipitation | Any form of water that falls from clouds and reaches Earth's surface. |
| rain gauge | An instrument used to measure the amount of precipitation. |
| droughts | Long periods of low precipitation. |
