Wednesday, August 26, 2009

Weather Fronts are Created by the Convergence of Temperatures

By Greg Hansward

The sun and atmosphere work together to create different climates. The air masses are moved by the changes in temperature. The disparate temperatures on the Earth's surface are caused by the different proximities of these areas to the sun. The equator is near the sun on the Earth's entire orbit.

This means that the surface on the Earth at the equator is hot, sunny and has many hours of daylight. An example is the warm Alicante weather. The poles are the farthest from the sun and are the coldest and darkest areas of the planet when it is winter and sunny but still cold in what is considered summer there. The farther from the equator you get, the more seasonal the climates become. The climates in the middle of the equators and poles at what are called the middle latitudes are four season climates.

The air moves in masses caused by these irregular heating patterns and the boundaries between them are called fronts. The atmosphere is constantly moving the air around in an attempt to gain equilibrium, or equalized pressure between the warm and cool air. Air that moves also hits stable air and all the molecules mix together. When the cold air moves into warm air, it is called a cold front; a warm front comes from the opposite motion of warm air into cold.

Warm fronts rise above and on top of cold air. As the warm air cools the molecules form water vapor, and become clouds. First are the high cirrus clouds, then come the aptly named mid level followed by thick stratus clouds. Thick stratus clouds are the ones that sometimes cause rain and wind conditions.

When a cold front hits a warm air mass, the result can be more volatile. Convection occurs when the cold front sharply pushes the instable warm air up. These winds create cumulus clouds and these clouds bring the thunderstorms. The upward motion also creates low pressure situations that make the wind blow harder. Along the cold air in front there will be the actual hard rain and sharp wind. The air behind it that has warmed a bit will simply bring rain. If the cold air takes over the warm air slowly, it becomes an occluded front and stratus clouds with light precipitation result. Stationary fronts occur when two very weak fronts meet and neither takes over the other. They simply sit and rain on the area until all of the air warms up or cools down and progresses on as a cold or warm front.

The oceanic regions of the Earth encompass 70% of the surface area. Climates in coastal areas are affected by the temperature of the seas, as saltwater is a very good conductor of both hot and cold temperatures. Great Britain is much warmer than most of the other land in its same latitude because of the warm Gulf Stream. - 16887

About the Author:

No comments: