Assessment Characteristic of Precipitable Water Vapor Using GNSS Satellite and Model ERA-5 in Surabaya, East Java, Indonesia Prasetyo Umar Firdianto (a*), Bangun Muljo Sukojo (b)
a) b) Geospatial Laboratory, Department of Geomatics Engineering, Sepuluh Nopember Institute of Technology, Kampus ITS Sukolilo, Surabaya 60111, Indonesia
*prasetyo.firdianto[at]bmkg.go.id
a) Maritime Meteorological Station of Tanjung Perak, Indonesia Agency of Meteorology Climatology and Geophysics (BMKG), Kalimas Baru Street 97b, Surabaya 60165, Indonesia
Abstract
Precipitable Water Vapor (PWV) is crucial parameter in weather analysis and forecasting because it determines total water vapor content in troposphere. Radiosonde (RA) as insitu observation has limitations in spatia and temporal resolution. GNSS Satellites based on zenith tropospheric delay and ERA-5 Model based on specific humidity can be used to monitoring spatiotemporal PWV. The Data used are Radiosonde observation, rinex of Cors Station-CSBY, hourly data on pressure level of ERA-5 Model, rainfall observation of Meteorological Station and GSMaP Satellite, and Water Vapor channel Himawari Satellite. The methods used are correlation analysis, regression, and based on extreme weather cases in 2022-2023. The results are GNSS-PWV and ERA5-PWV can represent PWV observation. Correlation are 0.90 and 0.86, RMSE 2.51 and 3.16. In addition, the ERA5 Model can describe PWV spatially and consistent to upper-level moisture observation of Himawari Satellite and rainfall of GSMaP Satellite in case of extreme weather event. Climatology of PWV is generally higher during Asian monsoon (DJF period, December-January-February) than in Australian monsoon (JJA period, June-July-August). According the result, GNSS-PWV can be used with high temporal resolution and ERA5-PWV spatially to build of weather and climate supplementary information.
