| A | B |
|---|
| thermometer | an instrument used for measuring temperature |
| barometer | an instrument used for measuring atmospheric pressure |
| air pressure | pressure exerted by the atmosphere |
| rain gauge | an instrument used to measure the amount of rain that has fallen |
| hygrometer | an instrument used to measure the water vapor content of the atmosphere |
| anemometer | an instrument that measures the speed or force of the windor |
| weather | the state of the atmosphere with respect to heat or cold, wetness or dryness, calm or storm, clearness or cloudiness |
| climate | the average course or condition of the weather at a place usually over a period of years |
| precipitation | a deposit on the earth of hail, mist, rain, sleet or snow |
| rain | precipitation in the form of liquid water droplets greater than 0.5 mm |
| snow | frozen precipitation in the form of white or translucent ice crystals |
| sleet | ice pellets; winter precipitation in the form of small bits of ice |
| evaporation | the physical process by which a liquid is transformed into a gaseous state |
| condensation | the process by which water vapor undergoes a change in state from a gas to a liquid |
| atmosphere | the gaseous or air portion of the physical environment that encircles a planet |
| cloud | a visible collection of minute particle matter, such as water droplets and/or ice crystals, in the free air. They form in the atmosphere as a result of condensation of water vapor |
| hail | precipitation that begins in clouds in the form of ice, having a diameter of 5 mm or more |
| humidity | the amount of water vapor in the air |
| jet stream | an area of strong winds in the Northern and Southern Hemisphere; flowing from west to east; it is causes by changes in air temperature when the cold polar air moving toward the equator meets the warmer equatorial air moving polarward |
| water current | a horizontal movement of water such as the Gulf Stream off the coast of North America |
