LAUSR

Abstract Estimating actual vapor pressure (ea) without relative humidity (RH) data continues to draw research attention. One of the accurate ways to estimate ea is through estimation of dew point temperature (Tdew) from minimum (Tmin) or mean temperature (Tmean). Two existing methods have been largely used to estimate ea. The first method (method I) assumes that Tdew is close to Tmin. The other one (method II) adjusts Tdew from Tmin with piecewise correction factors (aT) from sub-humid to hyper arid regions, and from Tmean with a fixed correction factor, aD, in humid regions. Here, two methods are proposed to estimate ea. The first method (method III) adjusts Tdew from Tmin with dynamic aT based on the correlation function between aT and aridity index (AI) regardless of climate zones. The second method (method IV) adjusts Tdew from Tmin with dynamic aT when AI