| A | B |
|---|
| Air mass | a body of air that has about the same temperature and humidity throughout |
| Air pressure | a measure of the weight of the atmosphere on a given area of the surface of the Earth; barometric pressure |
| Anemometer | an instrument used to measure wind speed |
| Atmosphere | an envelope of mixed gases are held to the Earth by gravity; the most dense gases are near the surface of the Earth |
| Convection current | when temperature differences cause liquids and gases (fluids) to expand and move; the less dense areas continually rise, and the more dense areas continually sink creating a cyclical current |
| Coriolis effect | the effect of the Earth’s rotation on the path of air and water; causes the path to curve |
| Humidity | amount of water vapor present in the air; relative humidity |
| Jet stream | narrow band of high speed wind high in the atmosphere; moves west to east in the Northern Hemisphere |
| Prevailing winds | global wind located at mid-latitude; mostly blows in one direction |
| Psychrometers | instrument used to measure humidity (moisture) in the air |
| Weather front | an area where two air masses with different temperatures and pressures meet |
