عنوان مقاله [English]
In this study all tries have been done to simplify & to determine a linear relation
between Relative Humidity and Dewpoint depression through the Clausius
Clapeyron and the Relative Humidity Equations, and also by using daily
experimental data in a period of years (- ) from Tehran meteorology
stations of North (an elevation of meters above sea level) & of Mehrabad (an
elevation of meters above sea level). This outcome has been obtained under
condition of the atmosphere and geographical ambient of Tehran city. In result, the
obtained linear Equation was RH=100-5.18(T-Td) which showed a decrease of Td
increase of Dewpoint depression by about 1oC for every % decrease in RH.
Therefore, there were several efficient usages for presented simple linear Equation.
One of them was to estimate cumulus cloud base level (LCL – lifting condensation
level). Considering the ratio changes of RH with Dewpoint depression, linear
Equation for estimating Cumulus cloud base level which is Zlcl = 125(T-Td)
changed in the form of Zlcl = 24.13(100-RH) .