WETAIR: Properties of Wet Air

In TrenchR: Tools for Microclimate and Biophysical Ecology

Properties of Wet Air

Description

The function calculates several properties of humid air described as output variables below. The program is based on equations from \insertCiteList1971;textualTrenchR and code implementation from NicheMapR \insertCiteKearney2017,Kearney2020TrenchR.
WETAIR must be used in conjunction with VAPPRS. Input variables are shown below. See Details.

Usage

WETAIR(db, wb = db, rh = 0, dp = 999, bp = 101325)

Arguments

db	numeric dry bulb temperature (C).
wb	numeric wet bulb temperature (C).
rh	numeric relative humidity (%).
dp	numeric dew point temperature (C).
bp	numeric barometric pressure (Pa).

Details

The user must supply known values for DB and BP (BP at one standard atmosphere is 101,325 pascals). Values for the remaining variables are determined by whether the user has either (1) psychrometric data (WB or RH), or (2) hygrometric data (DP):

Psychrometric data

If WB is known but not RH, then set RH = -1 and DP = 999. If RH is known but not WB then set WB = 0 and DP = 999.

Hygrometric data

If DP is known, set WB = 0 and RH = 0.

Value

Named list with elements:

e

numeric saturation vapor pressure (Pa)

vd

numeric vapor density (kg m^-3)

rw

numeric mixing ratio (kg kg^-1)

tvir

numeric virtual temperature (K)

tvinc

numeric virtual temperature increment (K)

denair

numeric density of the air (kg m^-3)

cp

numeric specific heat of air at constant pressure (J kg^-1 K^-1)

wtrpot

numeric water potential (Pa)

rh

numeric relative humidity (%)

References

\insertAllCited

Examples

  WETAIR(db = 30, 
         wb = 28, 
         rh = 60, 
         bp = 100 * 1000)

TrenchR documentation built on April 29, 2026, 9:07 a.m.