What is the surface pressure?
Surface pressure, also known as atmospheric pressure, is the pressure that exerts the air on the surface of the Earth. The air has the weight and effects of gravity on this mass cause air pressure. The air pressure varies according to the geographical region and the season. Changes in air pressure, throughout the year and in different parts of the Earth, are largely responsible for weather changes. Atmospheric pressure is usually measured by a barometer and is most often measured in units called Pascals (PA).
As a whole atmosphere of Earth is putting pressure on the ground equal to 100,000 Pascals or 100 kilopascals (KPA). This number represents the average surface pressure of the atmosphere on the ground. In fact, surface pressure can vary very much in different geographical areas. The differences in air pressure depends mainly on the seasons of the year and are considered to be responsible for most of the weather phenomenon.
from December to February, an area of high atmospheric pressure usually exist above North Africa and Spain, in the Pacific Ocean near California PIt will shout, over Central Asia, through Central North America and through subtropical ocean waters in the southern hemisphere. It can be expected that the southernmost regions of Greenland and Aleutian Islands will experience low surface pressure in these months of the year.
From June to August, these pressure systems usually change. High -pressure systems above Central Asia, as well as low -pressure systems in Greenland and Aleutian islands, generally disappear. High -pressure Pacific Ocean systems, Spain, North Africa and subtropical waters in the southern hemisphere generally grow stronger and reach north. During these months, it occurs over Antarctica and Australia, while central and south appear over Antarctica, and Australia Asia is developing low surface pressure, which said it contributes to the rains of this continent.
weather usually occurs when air moves from the area of high surface pressure to the low surface pressure area. The movement of air is commonly known as the wind and usually moves in samples in the shape of a spiral caused by the rotation of the Earth. The air subjected to higher surface pressure levels is usually thicker than the air subjected to low surface pressure levels; This difference in density usually contributes to air movement from high to low -pressure areas. The air generally becomes less dense when it moves into the areas of low atmospheric pressure. This change in air density often contributes to the development of atmospheric depression, which is characterized by clouds and precipitation.