Detection of tropical cyclone Seroja based on precipitable water vapor from InaCORS data Nabila S.E. Putri (a*), Dudy D. Wijaya (b), M. Rais Abdillah (c), Wedyanto Kuntjoro (b), Zamzam Tanuwijaya (b), Sidik T. Wibowo (d)
a) Surveying and Cadastre Research Group, Bandung Institute of Technology, Jl. Ganesha 10, Bandung, Indonesia
b) Geodesy Research Group, Bandung Institute of Technology, Jl. Ganesha 10, Bandung, Indonesia
c) Atmospheric Science Research Group, Bandung Institute of Technology, Jl. Ganesha 10, Bandung, Indonesia
d) Division for Horizontal Control Network and Geodynamics, Geospatial Information Agency (BIG), Jl. Raya Jakarta-Bogor Km. 46, Cibinong, 16911, Indonesia
Abstract
Tropical cyclones are low pressure systems created by a local heating of the sea surface, which triggers an intense convective activity involving large amounts of water vapor. A deadly tropical cyclone was formed in the early April 2021 over the Savu Sea and was given the name Seroja. This study aims to understand the characteristics of Seroja based on the precipitable water vapor (PWV) as derived from the Global Navigation Satellite Systems (GNSS) data. Observations at 22 permanent GNSS stations, as well as in situ meteorological sensors, in the Nusa Tenggara region from 1 March 2021 until 30 April 2021 were used for this purpose. Surface pressure values dropped significantly by more than 20 hPa, while relative humidity increased and temperature was reduced. Furthermore, during the formation of Seroja, PWV values gradually increased, reaching its peak around the time of when the cyclone was at its closest. After the cyclone had passed, PWV values decreased rapidly, dropping from around 70 mm to below 20 mm at CKUP. PWV pre-Seroja tends to be larger than post-Seroja, whereas post-Seroja PWV was more variable.
Keywords: GNSS, precipitable water vapor, tropical cyclone
