| A | B |
|---|
| weather | the condition of the atmosphere at a particular time and place. |
| meteorologist | scientist who studies weather. |
| 3 properties of air | space, mass and pressure. |
| air pressure | the weight of air pushing down on Earth's surface. |
| dense | molecules of air held tightly together. |
| barometer | instrument used to measure air pressure. |
| mercury barometer | measures air pressure by using a hollow tube filled with mercury. used most by weather research stations and laboratories. |
| aneroid barometer | used by people at their homes to measure air pressure. |
| atmosphere | blanket of air that covers the Earth which is composed of distinct layers. |
| anemometer | measrues wind speed. |
| wind vane | points the direction wind is blowing. |
| wind | horizontal movement of air across Earth's surface. |
| jet stream | where the strongest and most persistent wind is found.ent wind |
| weather balloons | determines how fast wind is moving in jet stream. |
| northern lights | a natural light show that can easily be seen at night in the northern hemisphere. |
| greenhouse effect | trapping of solar energy in the Earth's atmosphere. |
| global warming | a worldwide increase in the Earth's temperatures. |
| water cycle | a never ending process consisting of evaporation, condensation and precipitation. |
| evaporation | water changing from a liquid to a gas. |
| condensation | change from a gas to a liquid. |
| precipitation | water falling from the sky in the form of rain, snow, hail or sleet. |
| cloud | water droplets or ice particles suspended in air. |
| cummulus | large, thick, and puffy clouds and are often grey in center. |
| cirrrus | thin white clouds with feathery edges. |
| stratus | clouds that form at low altitudes and spread across sky in flat grey layers. |
| ranking clouds | condiering of the height and whether a cloud is flat or puffy by meterologists. |
| rain shadow | land on the side of the mountain away from the ocean that gets little rain. |
| desert | an area of land that receives less than 25 cm of rain per year. |
| transpiration | release of water vapor from plants. |
| irrigation | a way to artificially water the land. |
| air mass | a large body of air with nearly the same temperature and moisture throughout. |
| front | a place where 2 different air masses meet. |
| cold front | dense cold air slides under less dense warm air. may produce thunderstorms. |
| warm front | cirrus clouds tell you a warm front is coming. warm air rises up over the denser cold air. |
| nor easter | intense storm |
| tornado | a rapidly circling column of ait that moves over a narrown path of land. |
| hurricane | a violent storm that forms over a warm ocean. |
