The pressure exerted by the weight of the air above it at any point on the earth's surface. At sea level the atmosphere will support a column of mercury about high. This decreases with increasing altitude. The standard value for the atmospheric pressure at sea level in SI units is .
The pressure exerted by the weight of the air above it at any point on the earth's surface. At sea level the atmosphere will support a column of mercury about high. This decreases with increasing altitude. The standard value for the atmospheric pressure at sea level in SI units is .