
,
where 


where
the ratio of the molecular weight of water vapor to the molecular weight of dry air.
is the partial pressure of water vapor.
Relate these to the word description on http://meted.ucar.edu/awips/validate/thetae.htm
Specific hum in g/kg or kg/kg.
Absolute hum in g/m^3.
This is red text.
Simpler:
in mm/day.
in m/day.
in m/yr.
in m/yr.
evap(n).AllInc = (rho*omega*LatentHeatOfVap*k^2./fD(n).DPress) ./ ...
(log(H.SpdTop(n)./fD(n).DZ_kno).*log(H.Temper(n)./fD(n).Z_humi))...
/LatentHeatOfVap/rho_ice*100*10*3600*24 ...
.*fD(n).DSpdTo.* (fD(n).DVapPr - fD(n).VPsurf);