Calculate vapour pressure deficit from relative humidity

Source: R/calc_vpd.R

Follows Abtew and Meleese (2013), Ch. 5 Vapor Pressure Calculation Methods, in Evaporation and Evapotranspiration

calc_vpd(
  qair = NA,
  eact = NA,
  tc = NA,
  tmin = NA,
  tmax = NA,
  patm = NA,
  elv = NA
)

Arguments

qair

Air specific humidity (g g-1)

eact

Water vapour pressure (Pa)

tc

temperature, deg C

tmin

(optional) min daily air temp, deg C

tmax

(optional) max daily air temp, deg C

patm

Atmospehric pressure (Pa)

elv

Elevation above sea level (m) (Used only if patm is missing for calculating it based on standard sea level pressure)

Value

vapor pressure deficit (Pa)