- Weather: Topic Page
State of the atmosphere at a given time and place with regard to temperature, air pressure (see barometer), wind, humidity, cloudiness, and precipitation.
- Weather Forecasting
Prediction for changes in the weather. The forecast is based on several different types of information from several sources.
- Weather Stations
Data from meteorological stations and weather satellites are collated by computers at central agencies, and forecast and weather maps based on current readings are issued at regular intervals. Modern analysis, employing some of the most powerful computers, can give useful forecasts for up to six days ahead.
- Cyclones: Topic Page
Cyclone, atmospheric pressure distribution in which there is a low central pressure relative to the surrounding pressure.
- Earthquake: Topic Page
Trembling or shaking movement of the earth's surface. Most earthquakes are minor tremors.
- Erosion: Topic Page
General term for the processes by which the surface of the earth is constantly being worn away.
- Fog: Topic Page
Cloud that collects at the surface of the Earth, composed of water vapour that has condensed on particles of dust in the atmosphere. Cloud and fog are both caused by the air temperature falling below dew point.
- Frost: Topic Page
Frost or hoarfrost, ice formed by the condensation of atmospheric water vapor on a surface when the temperature of the surface is below 32°F (0°C).
- Greenhouse Effect: Topic Page
Phenomenon of the Earth's atmosphere by which solar radiation, trapped by the Earth and re-emitted from the surface as long-wave infrared radiation, is prevented from escaping by various gases (the ‘greenhouse gases’) in the air.
- Hurricane: Topic Page
Tropical cyclone in which winds attain speeds greater than 74 mi (119 km) per hr.
- Rain: Topic Page
Precipitation in liquid form.
- Snow: Topic Page
Precipitation formed by the sublimation of water vapor into solid crystals at temperatures below freezing.
- Tornado: Topic Page
Dark, funnel-shaped cloud containing violently rotating air that develops below a heavy cumulonimbus cloud mass and extends toward the earth.
- Tsunami: Topic Page
Series of catastrophic ocean waves generated by submarine movements, which may be caused by earthquakes, volcanic eruptions, landslides beneath the ocean, or an asteroid striking the earth. Tsunamis are also called seismic sea waves or, popularly, tidal waves.
- Volcano: Topic Page
Vents or fissures in the earth's crust through which gases, molten rock, or lava , and solid fragments are discharged.
- Wind: Topic Page
Flow of air relative to the earth's surface. A wind is named according to the point of the compass from which it blows.