Surface pressure
Encyclopedia
Surface pressure is 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.
Surface pressure is also the change of surface tension as a function of the area of water surface available to each molecule in a solution. The measurement of surface pressure is key in determining the monolayer properties of an amphiphilic material.
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
Atmospheric pressure
Atmospheric pressure is the force per unit area exerted into a surface by the weight of air above that surface in the atmosphere of Earth . In most circumstances atmospheric pressure is closely approximated by the hydrostatic pressure caused by the weight of air above the measurement point...
at a location on Earth
Earth
Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...
's surface. It is directly proportional to the mass
Mass
Mass can be defined as a quantitive measure of the resistance an object has to change in its velocity.In physics, mass commonly refers to any of the following three properties of matter, which have been shown experimentally to be equivalent:...
of air over that location.
For numerical reasons, atmospheric models such as general circulation models (GCMs) usually predict the nondimensional logarithm
Logarithm
The logarithm of a number is the exponent by which another fixed value, the base, has to be raised to produce that number. For example, the logarithm of 1000 to base 10 is 3, because 1000 is 10 to the power 3: More generally, if x = by, then y is the logarithm of x to base b, and is written...
of surface pressure.
Surface pressure is also the change of surface tension as a function of the area of water surface available to each molecule in a solution. The measurement of surface pressure is key in determining the monolayer properties of an amphiphilic material.
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