What does atmospheric pressure mean ? What does atmospheric pressure depend on ?
The unit force exerted on a certain surface by the atmospheric column above it is called atmospheric pressure.
Gases effective in the formation of the atmosphere exert a force on the objects with their weight. This resulting force is called atmospheric pressure. The atmospheric pressure measured by barometer is evaluated as “millibar” unit. Normal air pressure is determined by the weight of air falling at 15 ° C temperature, 45 ° latitude and 1 square centimeter at sea level. This weight is; It is 1033 grams. It is equal to 1013 millibar air pressure. The pressure of 1013 millibars is considered normal.
If it is below this value, cyclone (low pressure), if it is above; anticyclone (high pressure) is formed. The highest air pressure ever measured on the earth; It is 1079 millibars. At the lowest pressure; It is 886 miles. In 1643, a mercury-containing barometer was measured by a scientist named Toriçelli. Conducting this experiment was done at sea level and at 15 ° C. A one meter long, sealed pipe was inserted into the mercury container and opened and it was observed that the mercury contained in it remained stable at 76 centimeters. Atmospheric pressure may differ according to place and time.
Atmospheric pressure changes with temperature, elevation, gravity and dynamics factors like cyclons and anticyclons.