In any weather forecast, in addition to the standard temperature values and the presence of clouds and precipitation, such a parameter is necessarily found as atmospheric pressure. On each subject on the surface of the Earth, the huge pillar is in the air atmosphere presses. A standard level of atmospheric pressure is considered to be 760 mm mercury pillars at 0 ° C. However, rarely when you can observe exactly such a value. Atmospheric pressure is very changeable and extremely strongly dependent on the weather.
The lowest atmospheric pressure caused by natural natural processes can be fixed during the passage of cyclones - the rotating air mass with reduced air pressure. Cyclones are formed due to raising warm and wet air flows into the atmosphere, where they are condensed into the clouds. Since the air rises from the bottom up from the surface of the Earth, there remains the area of reduced pressure in its place.
In the entire history of meteo-bruises, it is in cyclones that the lower pressure in the earth's surface is recorded. The most intense are tropical cyclones that are found in the water area of the Pacific Ocean. In one of them, the cyclone type, which fell into the Japanese Islands in 1979 - the region of the lowest atmospheric pressure in the earth was recorded equal to 652, 6 mm mercury pillars. In addition, the type is recognized as the largest tropical cyclone in the history with a diameter of 2220 km, while the diameter of ordinary cyclones rarely exceeds 300 km.
In addition to cyclones, extremely low atmospheric pressure may occur in the torn. On August 20, 1904, a tornado formed near the city of Minneapolis, and in the first tens of seconds, the pressure in its center reached only 580 mm mercury post, which is an absolute observation record. However, no evidence and fixed states of measuring instruments of this unique phenomenon have not been preserved.
This is interesting: The atmospheric pressure on the top of Everest is the highest point of the world - is 112 mm mercury pillars.
Illustration: https://c2.staticflickr.com/6/5515/9250640478_1cd6009797_b.jpg | Barometer with atmospheric pressure measurement scale in hectopascals