How to calculate Specific Humidity

[Arlindo da Silva]

On Fri, Jul 24, 2009 at 10:21 PM, itesh dash <itesh.dash at gmail.com> wrote:

> Hi,
>
> Can anybody suggest how to calculate specific humidity using
> air temperature  (deg K) and relative humidity.
>
>


> The available GrASDS Script *tvrh2q* calculates specific humidity based on
> virtual temperature and relative humidity.
>
>

To a good approximation

  RH = e / e_s((T) ~ w / w_s(T)

where

   e = vapor pressure
   e_s = saturation vapor pressure
   w = mixing ratio
    w_s = saturation mixing ration