Variation of GNSS-derived Precipitable Water Vapor Over Manila in 2017

In this study, we present the variation of precipitable water vapor (PWV) derived from a Global Navigation Satellite System (GNSS) receiver located in Manila on 2017. Monthly mean variation was consistent to the climate classification of the site, i.e., Climate Type I based on modified Coronas classification. It showed increased levels of PWV occurred during the wet months (May to October), which peaked in July with PWV value of 61.1 mm. Meanwhile, it has decreased amounts during dry season (November to April) with minimum occurred in March with PWV of 39.9 mm. Wet season showed the least variation in monthly mean PWV where standard deviation (σ) ranged from 3.9 mm to 8.8 mm. On the other hand, most PWV variations occurred during the dry months where ranged from 6.2 to 9.9 mm. Moreover, monthly PWV shows moderate correlation with Surface temperature (R = +0.507), which shows that temperature in this time scale moderately contribute to the formation of water vapor in the atmosphere through evaporation. The results show the potential of GNSS-based PWV in examining the atmospheric moisture characteristics in an area which may be of use in future weather analysis and forecasts.