#### CbIncus

##### Member

The original paper by Schrader (http://journals.ametsoc.org/doi/abs/10.1175/1520-0450(1997)036<1725:COACFC>2.0.CO;2 - Calculations of Aircraft Contrail Formation Critical Temperatures) gives us tables of critical temperatures for different pressures, relative humidities and contrail factors. But it's only from 30 to 500 mb, lower levels are not included. The calculations are based on Goff-Gratch equation of saturation water vapor pressure. The provided source code and EXE file can help us to calculate Tcrit for any pressure level. The es(T) function and des/dT derivative are computed from Murphy-Koop formula, which is based on more recent data.

http://yadi.sk/d/hy75Iz934i-lO (Pascal source code)

http://yadi.sk/d/R0lQhzeE4i05K (EXE file)