Air pressure is primarily measured in several units, the most common of which include pascals (Pa), millibars (mb), and inches of mercury (inHg). Each unit serves a different context in which air pressure calculations and interpretations are made.
The pascal is the SI (International System of Units) unit for pressure, defined as one newton per square meter. It is widely used in scientific contexts. However, in meteorology, air pressure is often expressed in millibars, where 1 millibar is equivalent to 100 pascals. This is more practical for weather reports and atmospheric studies.
In the United States, air pressure is frequently reported in inches of mercury, the unit that came from early barometers that used a column of mercury to measure pressure changes. One standard atmosphere is equal to 29.92 inches of mercury.
Overall, understanding these different units is crucial for accurately interpreting weather data and studying atmospheric conditions.