On the relation between lightning flash density and terrain elevation

The distribution of lightning flash density over large areas depends on many factors. In this paper, we analyze one of them, namely the terrain elevation. Some previous studies suggest that the lightning flash density decreases above a certain altitude. We show that this conclusion could be affected by the used method of analysis and we suggest two improved methods. The lightning flash density distribution over Switzerland and Austria was used as an example to test the proposed methods. The results of the application of both methods suggest that the lightning flash density grows over the whole altitude range.