barometric pressure; weight of the atmosphere at a particular point of interest. Some Meteorologists use hPa - hectopascal for atmospheric air pressure. The hectopascal is equivalent to the mbar (millibar)
EESiFlo North America, Terminology and Glossary: Meteorological Weather Station Terms, Pennsylvania, USA 2002, flowmeterdirectory.com/flowmeter_terminology, (Wthr - Amer) {554}