Zenith tropospheric delay is one of the main atmospheric effects influencing high-precision GNSS positioning and the interpretation of geodetic time series. This study investigates seasonal variations of GNSS zenith tropospheric delay at the VARA station located in the Rivne Nuclear Power Plant region. The research is based on time series of zenith total delay, zenith hydrostatic delay, and zenith wet delay obtained from GNSS observations of the GeoTerrace network for the 2019–2025 period. The GNSS observations were processed using PRIDE PPP-AR software. To support meteorological interpretation, ERA5 reanalysis data were used, including air temperature and surface pressure obtained from the Copernicus Climate Data Store. ERA5 gridded hourly values were spatially interpolated to the VARA station values. The analysis included comparison of daily time series, monthly mean seasonal variations, and relationships between GNSS delay components and ERA5 meteorological parameters. The results show that the zenith total delay has a pronounced seasonal pattern, with increased values during the warm period of the year. The wet component demonstrates the strongest seasonal variability and generally follows the annual behaviour of ERA5 2 m air temperature. The hydrostatic component is more stable and shows an almost linear relationship with ERA5 surface pressure. The obtained results confirm the importance of accounting for seasonal tropospheric effects in GNSS data processing and geodetic monitoring near critical infrastructure.
Bevis, M., Businger, S., Herring, T. A., Rocken, C., Anthes, R. A., & Ware, R. H. (1992). GPS meteorology: Remote sensing of atmospheric water vapor using the Global Positioning System. Journal of Geophysical Research: Atmospheres, 97(D14), 15787–15801.
Doskich, S., & Serant, O. M. (2024). Verification of GNSS stations from the GeoTerrace network for further geodynamic studies using PS-NETM software. In International Conference of Young Professionals “GeoTerrace-2024” (Vol. 2024, No. 1, pp. 1–5). European Association of Geoscientists & Engineers. https://doi.org/10.3997/2214-4609.2024510008
Hersbach, H., Bell, B., Berrisford, P., Hirahara, S., Horányi, A., Muñoz-Sabater, J., ... & Simmons, A. (2020). The ERA5 global reanalysis, quarterly journal of the royal meteorological society.
Kladochnyi, B., Zablotskyi, F., & Serant, O. (2022). Analysis of seasonal changes of zenith tropospheric delay components determined by data of two pairs of aerological and GNSS stations. In International Conference of Young Professionals “GeoTerrace-2022” (Vol. 2022, No. 1, pp. 1–5). European Association of Geoscientists & Engineers. https://doi.org/10.3997/2214-4609.2022590006
Landskron, D., & Böhm, J. (2018). VMF3/GPT3: Refined discrete and empirical troposphere mapping functions. Journal of Geodesy, 92, 349–360.
Savchuk, S., & Zablotskyi, F. (2016). Monitoring of the tropospheric water vapor in the western cross-border zone of Ukraine. Geodesy, Cartography and Aerial Photography, 83, 21–33. https://doi.org/10.23939/istcgcap2016.01.021
Tekin Ünlütürk, N., & Doğan, U. (2024). The effect of seasonal variation on GNSS zenith tropospheric delay. The International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences, XLVIII-4/W9-2024, 371–376.