An Analysis of Lightning Activity in the Säntis Region through the Big Hiatus in Global Warming

The response of local lightning to local surface temperature is examined near the Säntis mountain (2502 m ASL) in the eastern Swiss Alps during the first of the two hiatuses in global warming covering the time periods 1940-1972 and 1998-2014. The mountain summit was used since 1881 as a telegraph and meteorology station and since 1955, 3 different towers have been installed at the top of the mountain. In order to take the effect of the presence of a tower and its height into consideration, and also to be able to compare the trend of data inside and outside the hiatuses, the analysis period (1931-1994) is subdivided into four different time intervals. Depending on the availability of the data, the combination of surface air temperature and number of thunderstorm days obtained from MeteoSwiss were used to investigate the sensitivity of lightning activity to changes in surface air temperature at monthly and yearly timescales. The results show a clear difference between the hiatus and post-hiatus intervals and seem to support the idea that the lightning activity is correlated with the surface air temperature.