The impacts of GPS PWV during heavy thunderstorms over Kuala Terengganu, Malaysia

The understanding of thunderstorm activity in the middle atmosphere down to Earth surface and its relationship with a global warming phenomenon poses a great challenge for observational and prediction studies. This paper utilized the GPS as a tool to monitor the tropospheric precipitable water vapor (PWV) impacts as a climate variable due to heavy thunderstorm activity. The analysis of PWV data during the period of 2009 over Kuala Terengganu, Malaysia (KUAL) showed that from 10 heavy thunderstorm days recorded, about 90% of the event occurred in the afternoon (16∶00 ∼ 22∶00 LT) and at the rest occurred in the morning (00∶00 ∼ 01∶00 LT). During the heavy thunderstorm days, the PWV maximum was 48.59 mm and observed to occur between 13∶00 LT and 14∶00 LT. This value was higher 3.30 mm than the one-year maximum PWV average (45.30 mm). Furthermore, PWV increased about ∼5.0 mm within 7 hours from the minimum point, and gradually decreased three hours before the heavy thunderstorm occurred with PWV was 45.31 mm. Most of the event also showed that, the PWV during and after the heavy thunderstorms were lower than a year. However, the scenario is contrast for the morning thunderstorm that will be discussed in the paper.