1Institute of Atmospheric and Cryospheric Sciences, University of Innsbruck, Innsbruck, Austria
2Department of Statistics, University of Innsbruck, Innsbruck, Austria
3OVE-ALDIS, Vienna, Austria
Received: 01 Jun 2016 – Discussion started: 04 Jul 2016
Abstract. This study develops methods for estimating lightning climatologies on the day−1 km−2 scale for regions with complex terrain and applies them to summertime observations (2010–2015) of the lightning location system ALDIS in the Austrian state of Carinthia in the Eastern Alps.
Revised: 16 Jan 2017 – Accepted: 08 Feb 2017 – Published: 06 Mar 2017
Generalized additive models (GAMs) are used to model both the probability of occurrence and the intensity of lightning. Additive effects are set up for altitude, day of the year (season) and geographical location (longitude/latitude). The performance of the models is verified by 6-fold cross-validation.
The altitude effect of the occurrence model suggests higher probabilities of lightning for locations on higher elevations. The seasonal effect peaks in mid-July. The spatial effect models several local features, but there is a pronounced minimum in the north-west and a clear maximum in the eastern part of Carinthia. The estimated effects of the intensity model reveal similar features, though they are not equal. The main difference is that the spatial effect varies more strongly than the analogous effect of the occurrence model.
A major asset of the introduced method is that the resulting climatological information varies smoothly over space, time and altitude. Thus, the climatology is capable of serving as a useful tool in quantitative applications, i.e. risk assessment and weather prediction.
Simon, T., Umlauf, N., Zeileis, A., Mayr, G. J., Schulz, W., and Diendorfer, G.: Spatio-temporal modelling of lightning climatologies for complex terrain, Nat. Hazards Earth Syst. Sci., 17, 305-314, doi:10.5194/nhess-17-305-2017, 2017.