Weather is always moving and changing. This is due greatly to high pressure, low pressure and the wind. The elements of which weather is made are heat, pressure, wind and moisture. Without the interacting of these elements there would be no changes in the weather. Without winds there would be changes in air pressure, no storms, rain nor snow.
Heat is the source that mixes the atmosphere to make weather. The sun’s energy is transmitted as waves that are similar to radio waves. Most of the solar energy is lost in space, only traces reach the earth. Approximately 43% of the sun’s radiation reach our planet and is changed to heat, the remainder stays in the atmosphere or is reflected into space.
The earth’s atmosphere acts like a greenhouse. The earth’s atmosphere admits most of the solar radiation and when it is absorbed by earth’s surface it is re-radiated as heat waves. These heat waves are trapped by vapor in the atmosphere and the earth is kept warm.
Local winds and breezes are caused by convection. Different land and water surfaces absorb different amounts of heat. Dark soil absorbs more heat than grassy fields. During the day, mountains absorb more heat than valleys and lose it faster at night.
The air is heated primarily by its contact with the warm earth. When air is warmed it expands and becomes lighter. As a layer of air is warmed, it rises and is replaced by colder air which flows in under it. This cycle is called convection. So warm air at the equator is replace by colder air flowing in from the north and south poles. The light air rises and moves poleward where it is cooled and sinks, replacing the cool surface air which moves toward the equator.
The air atmosphere that surrounds the earth is made up of layers of gases that protect us from extreme cold or heat. The lowest layer is the troposphere. The troposphere contains water vapor and is where our weather occurs.