stability.parameter {bigleaf}

Stability Parameter "zeta"

Description

calculates "zeta", a parameter characterizing stratification in the lower atmosphere.

Usage

stability.parameter(
  data,
  Tair = "Tair",
  pressure = "pressure",
  ustar = "ustar",
  H = "H",
  zr,
  d,
  constants = bigleaf.constants()
)

Arguments

data

Data.frame or matrix containing all required variables

Tair

Air temperature (degC)

pressure

Atmospheric pressure (kPa)

ustar

Friction velocity (m s-1)

H

Sensible heat flux (W m-2)

zr

Instrument (reference) height (m)

d

Zero-plane displacement height (m)

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 stability parameter \zeta is given by:

\zeta = (zr - d) / L

where L is the Monin-Obukhov length (m), calculated from the function Monin.Obukhov.length. The displacement height d can be estimated from the function roughness.parameters.

Value

\zeta - stability parameter zeta (-)

Examples

df <- data.frame(Tair=25,pressure=100,ustar=seq(0.2,1,0.1),H=seq(40,200,20))
stability.parameter(df,zr=40,d=15)