Estimation of precipitable water vapour in Nigeria using surface meteorological data

Abstract

In this work, relatively cheap and easy to measure surface meteorological data such as ambient temperature, relative humidity, vapour pressure and dew-point temperature, had been collected from the Nigerian Meteorological Agency (NIMET). Using the analytically derivable Butler's equation, precipitable water vapour (PWV) had been estimated. For the purpose of this work, Nigeria was divided into four climatic regions and for each region empirical models of the form PWV (T ) and PWV (RH) were found; where T was the surface dew- d d point temperature and RH the surface relative humidity. The empirical models found were validated against the NCEP-DOE Reanalysis II data and found to be useful in estimating precipitable water vapour.

Keywords: Precipitable Water Vapour, Reanalysis II, Relative Humidity, Dew-point Temperature