f(t, u, Pa, Ht, Zwind, Zref)
- Calculates the interval Drying Power for modules evap and evap2.
Units
- (mm/kPa/Interval)
Inputs
- t (°C) - air temperature.
- Pa (kP) - atmospheric pressure.
- u (m/s) - wind speed.
- Ht (m) - crop height.
- Zwind (m) - wind measurement height.
- Zref (m) - temperature/humidity measurement height.
Returns
- return( (0.622 * kappa*kappa * rhoa(t, Pa) * u * Interval*3600*24) / (Pa * x1 * x2))
where
d0 = 0.67*Ht and Z0 = 0.14*Ht
x1 = log( (Zwind-d0)/(Z0))
x2 = log( (Zref-0.67*Ht)/(Z0))
rhoa(t, Pa) = Density of air at (t, Pa).
kappa = 0.4 von Karman constant.
Interval = fraction of day.
Reference