|
Meteorology is so named because it was once thought that all the variations in the world's weather were due to the influence of meteorites entering the earth's atmosphere.
Introduction
Heat from the sun drives all the major wind systems around the world. It is like any fire, as the heat rises it causes areas of low pressure, that draws in the cold air around it. As the hot air cools and falls it creates an area of higher pressure. The average air pressure is 1013mb.
Water vapour causes cloud and fog and is responsible for much of the active weather we experience because it moves heat energy around. Warm air can hold much more water than cold air. As warm air cools, water vapour may condense into clouds. Clouds at sea level are known as fog. Water is constantly evaporating from the seas, lakes and moist ground, and this evaporation absorbs heat energy (latent heat). This is similar to sweating which cools the body as it evaporates.
This moisture travels around the world and wherever it condenses back into water the same amount of heat energy that was used in evaporation is released back into the atmosphere. Tropical cyclones and thunderstorms derive much of their energy directly from this source, i.e., the release of heat by the condensation of the water vapour. That is why wherever you have rain you are likely to have stronger winds due to the extra energy available from the release of latent heat.
|
|
