Surface pressure often refers to the atmospheric pressure at a location on Earth's surface. It is directly proportional to the mass of air over that location.
For numerical reasons, atmospheric models such as general circulation models (GCMs) usually predict the nondimensional logarithm of surface pressure.
The average value of surface pressure on Earth is 985hPa. This is in contrast to mean sea-level pressure, which involves the extrapolation of pressure to sea-level for locations above or below sea-level. The average mean sea-level pressure is 1013.25hPa, or 1 atmosphere (Atm).
Pressure (P), mass (m), and the acceleration due to gravity (g), are related by P = F/A = (m*g)/A, where A is surface area. Atmospheric pressure is thus proportional to the weight per unit area of the atmospheric mass above that location.
Surface Pressure - Area Isotherms
Famous quotes containing the words surface and/or pressure:
“Here Men from The Planet Earth
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We Came in Peace for All Mankind”
—Plaque left behind on the moon’s surface by the crew of Apollo 11.
“Osteopath—One who argues that all human ills are caused by the pressure of hard bone upon soft tissue. The proof of his theory is to be found in the heads of those who believe it.”
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