An Estimation of Precipitable Water Vapour Around Surabaya City Using GIPSY-X

Precipitable water vapor is a crucial climatic parameter that indicates the available humidity in the atmosphere. Precipitable water vapor is produced by evaporation/evapotranspiration from the surface to the atmosphere and thus plays an important role in the water cycle. As an essential indicator of climate change, water vapor contributes significantly to the thermodynamics of the atmosphere. Zenith Total Delay can be calculated using the Precise Point Positioning strategy and all parameters. Using the parameter mapping function, Slant Tropospheric Delay can be converted to Zenith Total Delay, which is affected by temperature, pressure, and humidity. We processed the GNSS data from five stations surrounding Surabaya City using GipyX. Advanced processing generates five minutes of ZTD estimation on each station for five years of observation. A high correlation of ZTD estimated using GipsyX (corr = 0.88) with ZTD at meteorological rinex data of DARW station shows our estimation's promising and dependable result. The ZTD time series shows consistent patterns on each station, showing the significant contribution of regional signals such as monsoon and ENSO.