The relationship between raining and GPS-precipitable water vapor

Abstract

Precipitable water vapor (PWV) can be retrieved from the delayed of the propagating GPS signal through the wet atmosphere. In the experiment, the GPS data in 2009 from the permanent GPS station name of CUSV were used to estimate the amount of integrated vertical water vapor above the GPS station in term of PWV. The results showed that the PWV were fluctuated all year long with their averaged of 31.05 mm. At the beginning of the year, the PWV were slightly increased until reach a plateau around DOY 120. This plateau was higher than their averaged around 10 mm in six months during the midyear. Then, the PWV gradually decreased until the end of the year. In addition, the strongly relationship between the rainy day and the PWV was found. 95.76 % of total rainy days (165 days) confirmed that the PWV were higher than their averaged. On the other hand, 69.00 % of total non-rainy days (200 days) showed that the PWV were lower than their averaged. Therefore, the PWV can be used as the key indicator of rain prediction.