Arden Buck equation

The Arden Buck equations are a group of empirical correlations that relate the saturation vapor pressure to temperature for moist air. The curve fits have been optimized for more accuracy than the Goff–Gratch equation in the range −80 to 50°C.

A set of several equations were developed, each of which is applicable in a different situation.

Formula

The equation suggested by Buck (1996) (which is a modification of the equation in Buck (1981)) is:

$p_w = 6.1121 \exp \left(\left( 18.678 - \frac{t} {234.5}\right)\left( \frac{t} {257.14 + t} \right)\right)$

where:

• p_w is the saturation vapor pressure in hPa
• exp is the natural (i.e. base e) exponential function
• t is the air temperature in degrees Celsius

See also

• Vapour pressure of water
• Antoine equation
• Goff–Gratch equation

References

• Buck, A. L. (1981), "New equations for computing vapor pressure and enhancement factor", J. Appl. Meteorol. 20: 1527–1532, http://ams.allenpress.com/perlserv/?request=get-pdf&doi=10.1175%2F1520-0450%281981%29020%3C1527%3ANEFCVP%3E2.0.CO%3B2 
• Buck (1996), Buck Research Manual 

External links

• Web Page listing various vapor pressure equations