bigleaf (version 0.8.2)

pressure.from.elevation: Atmospheric Pressure from Hypsometric Equation

Description

An estimate of mean pressure at a given elevation as predicted by the hypsometric equation.

Usage

pressure.from.elevation(
  elev,
  Tair,
  VPD = NULL,
  constants = bigleaf.constants()
)

Value

pressure -

Atmospheric pressure (kPa)

Arguments

elev

Elevation a.s.l. (m)

Tair

Air temperature (deg C)

VPD

Vapor pressure deficit (kPa); optional

constants

Kelvin- conversion degC to Kelvin
pressure0 - reference atmospheric pressure at sea level (Pa)
Rd - gas constant of dry air (J kg-1 K-1)
g - gravitational acceleration (m s-2)
Pa2kPa - conversion pascal (Pa) to kilopascal (kPa)

Details

Atmospheric pressure is approximated by the hypsometric equation:

$$pressure = pressure_0 / (exp(g * elevation / (Rd Temp)))$$

References

Stull B., 1988: An Introduction to Boundary Layer Meteorology. Kluwer Academic Publishers, Dordrecht, Netherlands.

Examples

# mean pressure at 500m altitude at 25 deg C and VPD of 1 kPa
pressure.from.elevation(500,Tair=25,VPD=1)