ESS220
Prof. Jin-Yi Yu
Units of Atmospheric Pressure
q Pascal (Pa): a SI (Systeme Internationale) unit for air pressure.
q     1 Pa = a force of 1 newton acting on a surface of one square  
q                 meter
q      1 hectopascal (hPa) = 1 millibar (mb)  [hecto = one hundred =100]
qBar: a more popular unit for air pressure.
q     1 bar = a force of 100,000 newtons acting on a surface of one
q                  square meter
q              = 100,000 Pa
q              = 1000 hPa
q              = 1000 mb
qOne atmospheric pressure = standard value of atmospheric pressure at lea level = 1013.25 mb = 1013.25 hPa.