Study of the relationship between relative humidity and the dewpoint depression in moist air on surface in period of five years (-) in stations of Mehrabad and North of Tehran
Subject Areas : Marine Physics
R.
Haroutounian
1
(Engineering Command of Constalations of nezaja)
Keywords: Wet bulb Temperature (Tw), Relative Humidity (RH), Dewpoint depression (T-Td), deficit (T-Tw) Cumulus cloud base height (Zlcl),
Abstract :
In this study all tries have been done to simplify & to determine a linear relationbetween Relative Humidity and Dewpoint depression through the ClausiusClapeyron and the Relative Humidity Equations, and also by using dailyexperimental data in a period of years (- ) from Tehran meteorologystations of North (an elevation of meters above sea level) & of Mehrabad (anelevation of meters above sea level). This outcome has been obtained undercondition of the atmosphere and geographical ambient of Tehran city. In result, theobtained linear Equation was RH=100-5.18(T-Td) which showed a decrease of Tdincrease 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 condensationlevel). Considering the ratio changes of RH with Dewpoint depression, linearEquation for estimating Cumulus cloud base level which is Zlcl = 125(T-Td)changed in the form of Zlcl = 24.13(100-RH) .