| A | B |
|---|
| Aerosols | A suspension in the atmosphere of solids such as dust, salt, and pollen, and liquid droplets such as acids. |
| Weather | Current condition of the atmosphere including cloud cover, temperature, wind speed and direction, humidity, and air pressure. |
| Precipitation | Occurs when drops of water or crystals of ice become too large to be suspended in a cloud and fall in the form of rain, freezing rain, sleet, snow, or hail. |
| Hurricane | Large storm, up to 970 km in diameter, that begins as low-pressure area over tropical oceans, has sustained winds that can reach 250 km/h and gusts up to 300 km/h. |
| Tornado | Violent, whirling wind, usually less than 200 m in diameter, that travels in a narrow path over land and can be highly destructive. |
| Front | Boundary that develops where air masses of different temperatures collide and contain nearly all of its clouds and weather. |
| Air Mass | Large body of air that develops over a particular region of Earth's surface. |
| Humidity | Amount of water vapor in the atmosphere. |
| Troposphere | Layer of the atmosphere that is closest to Earth's surface and contains nearly all of its clouds and weather. |
| Dew point | Temperature at which air is saturated and condensation can occur. |
| Water Cycle | Never ending cycle in which water cirulates between Earth's surface and the atmosphere through the processes of evaporation, transpiration, precipitation, and condensation. |
| Atmosphere | Layer of gases surrounding Earth that protects living things against harmful doses of ultraviolet radiation and X-ray radiation and absorbs and distributes warmth. |
| Relative Humidity | Meaure of the amount of watervapor in the air compared with the amount that could be held at a specific temperature. |
