RTLRA - Real-time Lightning Risk Assessment

Thunderstorms and lightning discharges pose a serious safety risk to people and have a signifi-cant impact on our infrastructure systems. Their unpredictable course repeatedly challenges our society in work-related and private activities. The changes in the climatic situation and local me-teorological influences make it difficult to assess the course of such natural events. Preliminary scientific work has shown that there is still a great need for research in the field of qualitative and local forecasting of thunderstorms. Dynamic processes of the charge deposing process in the cloud before the onset of thunder-storm activity and the different course of each thunderstorm make a prediction of the first light-ning discharge by already available metrological measurement principles impossible. Lightning detection systems also cannot provide predictive measurement data and cannot be used for de-cisions and actions until the first discharge at the earliest. The same circumstances apply to the time after the last lightning discharge of a thunderstorm. The large uncertainty in pre-warning and post-thunderstorm warning clearance for a given site with currently available data reinforces future innovations on the topic of "Realtime Lightning Risk Assessment". Electric field mills (FMs) are the only technical way to capture information about the current electrical charge state in a thunderstorm cell, even before the first lightning occurs, and to track the charge distribution history of the thunderstorm structure. In order to advance the methods of local assessment of thunderstorm activities technically and scientifically, the electrostatic field distribution shall be recorded continuously by the local deployment of several FMs in the area of a vulnerable zone in the infrastructure sector (e.g. airport runway), at large events or work areas with high thunderstorm exposure. Together with the project partner, the planned FM measurement network is to be installed in the catchment area of Graz Airport in coordination with the local operators. The very high frequency of thunderstorms in the south of Graz and the proximity to the Graz University of Technology as well as the large open areas, with activities of staff and passengers in the area of the runway, are optimal for the chosen basic research approach. Airport operations are severely impacted by approaching thunderstorm activity when work on the open field has to be completely stopped during a thunderstorm (shutdown). For operations, this means that all work in unprotected areas must be shut down to protect employees and passengers, and shut-down periods of a few minutes to several hours may occur. Combined data from this FM network represent the electric field strength prevailing in the vicin-ity and allow statements to be made about the dynamic course of thunderstorms due to the structural distribution of the FM probes. The correlation and logical linking of the FM measure-ment data with lightning location data and other meteorological data has, in the view of the ap-plicants, the potential for optimizing airport operations during thunderstorms, both from a safety and economic perspective. Both the applicant and the project partners have been active in international lightning research and lightning protection for many years and got competence to setup and operate the network and to handle teh logical linking with lightning location data and local meteorological data.