Moist thermodynamic functions in Meteorology

epmet.R

eps <- 0.622

e2q <- function (e, p) {
  eps*e/(p-(1.0-eps)*e)
}

q2e <- function(q, p) {
	p*q/(eps+(1.-eps)*q)
}

e2w <- function(e, p) {
	eps*e/(p-e)
}

calc.es <- function(T) {
# WMO, JMA
	exp(19.482-4303.4/(T-29.65))*100
}

calc.condtemp <- function (T, e){
#; Bolton (1980)
#; e(Pa)
	2840.0/(3.5*log(T)-log(e*0.01)-4.805)+55.0
}

ttd2q <- function(ttd, T, p) {
	e2q(calc.es(T-ttd), p)
}

rh2q <- function (rh, T, p) {
# T K, rh %
	e2q(calc.es(T)*0.01*rh, p)
}

q2ttd <- function(q, T, p) {
# WMO, JMA
  T-29.65-4303.4/(19.482-log(q2e(q,p)*0.01))
}

calc.theta <- function (T, w, p) {
# Bolton (1980)
# T(K), w(kg/kg), p(Pa)
	T*(100000.0/p)^(0.2854*(1.0-0.28*w))
}

calc.thetae <- function (T, e, p) {
# Bolton (1980)
# T(K), e(Pa), p(Pa)
	w <- e2w(e,p)
	TL <- calc.condtemp(T, e)
	calc.theta(T, w, p) * exp((3376.0/TL-2.54)*w*(1.0+0.81*w))
}

calc.thetaes <- function(T, p) {
# Bolton (1980)
# T(K), e=es(T)(Pa), p(Pa)
	es <- calc.es(T)
	w <- e2w(es,p)
	calc.theta(T, w, p) * exp((3376.0/T-2.54)*w*(1.0+0.81*w))
}