Monin.Obukhov.length: Monin-Obukhov Length

In bigleaf: Physical and Physiological Ecosystem Properties from Eddy Covariance Data

Monin-Obukhov Length

Description

calculates the Monin-Obukhov length.

Usage

Monin.Obukhov.length(
  data,
  Tair = "Tair",
  pressure = "pressure",
  ustar = "ustar",
  H = "H",
  constants = bigleaf.constants()
)

Arguments

data	Data.frame or matrix containing all required variables
Tair	Air temperature (deg C)
pressure	Atmospheric pressure (kPa)
ustar	Friction velocity (m s-1)
H	Sensible heat flux (W m-2)
constants	Kelvin - conversion degree Celsius to Kelvin cp - specific heat of air for constant pressure (J K-1 kg-1) k - von Karman constant (-) g - gravitational acceleration (m s-2)

Details

The Monin-Obukhov length (L) is given by:

L = - (ρ * cp * ustar^3 * Tair) / (k * g * H)

where rho is air density (kg m-3).

Value

L -	Monin-Obukhov length (m)

Note

Note that L gets very small for very low ustar values with implications for subsequent functions using L as input. It is recommended to filter data and exclude low ustar values (ustar < ~0.2) beforehand.

References

Foken, T, 2008: Micrometeorology. Springer, Berlin, Germany.

See Also

stability.parameter

Examples

Monin.Obukhov.length(Tair=25,pressure=100,ustar=seq(0.2,1,0.1),H=seq(40,200,20))

bigleaf documentation built on Aug. 22, 2022, 9:09 a.m.