Presentation information


IAG Symposia » G06. Geodetic remote sensing

[G06-P] Poster

Tue. Aug 1, 2017 3:30 PM - 4:30 PM Shinsho Hall (The KOBE Chamber of Commerce and Industry, 3F)

3:30 PM - 4:30 PM

[G06-P-05] Regional Precipitation Prediction Based On Tropospheric Gradients and Delay Time Series

Janina Boisits1, Gregor Moeller1, Christoph Wittmann2, Robert Weber1, Johannes Boehm1 (1.TU Wien - Department of Geodesy and Geoinformation, Vienna, Austria, 2.Central Institution for Meteorology and Geodynamics, Vienna, Austria)

Changes of temperature and humidity in the neutral atmosphere cause variations in tropospheric path delays and tropospheric gradients. Thus, time series of GNSS-based tropospheric parameters provide information about spatial and temporal variations of water vapour in the atmosphere and, therefore, can contribute to the forecast of regional precipitation events.
In a recently finalized master thesis at TU Wien the information content of tropospheric parameters for weather prediction was investigated. Two characteristics in ZWD and gradient time series can be anticipated in case of an approaching weather front. First, an induced asymmetry in tropospheric delays results in both, an increased magnitude of the gradient and in gradients pointing towards the weather front. Second, an increase in ZWD reflects the increased water vapour concentration right before a precipitation event. To investigate these characteristics exemplary test events were processed. Therefore, ZWD and gradient time series at selected GNSS reference stations were compared to precipitation data. All required meteorological data was provided by the Central Institution for Meteorology and Geodynamics (ZAMG).
It can be deduced, that GNSS-based tropospheric parameters show high potential for predicting precipitation events. The sequence of the anticipated increase in ZWD at each GNSS station indicates the orientation of the air mass boundary. Furthermore, the magnitude of ZWD increase at each station suggests, whether the station is affected by the precipitation event or not. Gradients rather indicate the direction of movement of an approaching weather front. Additionally our investigations have shown, that gradients are able to capture the characteristics of an approaching weather front twenty to thirty hours before the precipitation event, which allows a first indication well in advance.