List of of weather definitions.

View the summary of key terms.

ALL | A B C D E F G H I L M N O P R S T W
Temperature Inversion
This is a feature occuring in the early morning after a clear night, when terrestrial radiation is lost to space and the air near the ground has become cooler than the air above.
The Atmosphere
An envelope of air composed mainly of nitrogen and oxygen, which stretches from the earth's surface to about l00km above our planet.
The Biophysical Environment
The interaction of the atmosphere, hydrosphere, lithosphere and biosphere.
The Biosphere
The system of living things and non-living environment with which they interact.
The Greenhouse Effect
This is a natural warming process of the earth where the earth's atmosphere has always retained heat from the sun by a process similar to that which takes place in a greenhouse. This works by the glass trapping the incoming short wave solar energy and preventing it from re-entering back into space as it has changed to long wave radiation. The temperature rises as more heat enters the greenhouse than escapes. In the case of the atmosphere it is not glass but a blanket of carbon dioxide, water vapour and other greenhouse gases. such as methane, which refract and reflect the heat energy and so prevent its outflow. When the sun's energy reaches the earth, some of it is reflected back to space and the rest is absorbed. The absorbed energy . warms the earth's surface, which then emits heat energy back toward space as longwave radiation. This outgoing longwave radiation is partially trapped by greenhouse gases such as carbon dioxide, methane and water vapour, which then radiate the energy in all directions, warming the earth's surface and atmosphere.
The Hydrospher
The layer of water that cover the earth from a maximum depth of more then 11km in the oceans to shallower and less extensive bodies of water in lakes and river.
The Lithosphere
The sphere of rocks or upper layer of the mantle, which lies above the hot, semi molten and deformed rock of the deeper earth's mantle.
The Radiation Balance
This is a comparison of the energy gained and lo t (inputs and outputs of energy).
The Stratosphere
The layer from about 12,000 meters to about 50kms above the surface–this is where the sky is always clear, there is no water vapour and no changes in the weather.
The Thermal Equator
A belt of heat about ten degrees either side of the equator.
The Troposphere
The lowest layer nearest the surface i.e. where all our weather patterns develop (12,000m above the surface).
The Water Cycle
The movement of water from the sea to clouds: to rain or snow: to rivers or underground and back to the sea.
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