Mean Sea Level (MSL) is the average height of the sea surface when it is not influenced by temporary factors like tides or weather. It serves as a reference point for measuring elevations and altitudes on land and is used as a standard in aviation, cartography, and geodesy.
- “T0” is the standard temperature at sea level, approximately 288.15 kelvin (K).
- “L” is the temperature lapse rate, which is the rate at which temperature decreases with altitude (usually assumed as -0.0065 K/m in the troposphere).
- “P0” is the standard atmospheric pressure at sea level, approximately 101,325 pascals (Pa) .
- “P” is the actual atmospheric pressure at the given altitude (in pascals, Pa).