Atmospheric Pressure Essays Example

Atmospheric pressure is the pressure exerted on an area by the weight of air above the surface of the land. On a certain plane, low-pressure areas are those with less atmospheric mass above them while high-pressure areas are those with a higher atmospheric mass above them. Atmospheric pressure decreases with an increase in altitude. This is because, as altitude increases, there is lesser and lesser overlying atmospheric mass, hence less atmospheric pressure.
Perhaps more than any other single measurement, atmospheric pressure is the best indicator of current and changing weather conditions. This is because the weather characteristics in an area such as rainfall, cloud cover and sunshine are usually related to the pressure system in the area. Thus, knowledge of existing and expected atmospheric pressure distribution enables meteorologists to determine the weather conditions that will be expected in a particular area.
A low-pressure system is a region where the atmospheric pressure that is at sea level is below that of the adjacent regions. A low-pressure system is associated with cloudy, rainy or snowy weather. Areas around the world that experience low-pressure systems include Tibetan Plateau and the lee of the Rocky Mountains.
A high-pressure system is a region where the atmospheric pressure that is at sea level is higher than that of the adjacent regions. High-pressure systems are associated with plenty of sunshine, low cloud cover and lower rainfall amounts. An area that usually experiences high-pressure system is Tonsontsengel in Mongolia. In fact, it has the highest pressure ever recorded on Earth (1085.7 hectopascals).
A high value of air pressure will cause air to be compressed. With lower values of air pressure, air is less compressed. Compression of air leads decreases the volume of the air and increases its temperature.

References

Roger G. Barry and Richard J. Chorley. Atmosphere, Weather and Climate (5 ed.) Routledge pp 194-199.