European Electromagnetics (EUROEM), Lausanne, Switzerland 2008
Considering the importance of global warming and climate change, the problem of possible relationships between climate and lightning activity has recently attracted the attention of researchers (e.g. ). Positive correlations between global lightning activity and global temperature variations have been already confirmed in several studies (e.g. [1,2]) where it has been shown that a 1-degree Celsius variation in the temperature would result in an increase of lightning activity, ranging from 10% to 100% . In this paper, we present a preliminary regional study of the link between temperature and lightning activity in Switzerland. Lightning statistics were obtained from the lightning database of the EUCLID (European Cooperation of Lightning Detection) network, recently presented in . Any unknown time variations in the performance of the system are necessarily neglected. Data for the temperature are obtained from the terrestrial meteorology stations in the national network of the Swiss Federal Office of Meteorology and Climatology . Fig. 1a presents the monthly negative cloud-to-ground flash count and the monthly mean maximum daily temperature in Switzerland for the months of August, 1999-2006, where the linear correlation factor is 75%. A similar analysis has been done in the region of the Säntis in northeastern Switzerland, characterized by the highest lightning activity in that country. Fig. 1b shows the monthly mean of maximum daily temperature and the monthly number of the negative cloud-to-ground flashes within 100 km of the Säntis Mountain. The results show an 83% linear correlation.
Acknowledgments - This work has been partially supported by the European COST Action P18 ‘The Physics of Lightning Flash and Its Effects’.
1. C. Price, Global surface temperatures and the atmospheric electric circuit, Geophys. Res. Lett. 20, 1363, 1993.
2. E.R. Williams, Lightning and climate: A review, Atmospheric Research, 76, pp. 272-287, 2005
3. P. Manoochehrnia, F. Rachidi, M. Rubinstein, W. Schulz, Lightning statistics in Switzerland, 9th International Symposium on Lightning Protection, SIPDA, Foz do Iguaçu, Brazil, November 2007.
4. M. Begert, T. Schlegel, and W. Kirchhofer, Homogeneous Temperature and Precipitation Series of Switzerland from 1864 to 2000, International Journal of Climatology, vol. 25, pp. 65-80, 2005.
Monthly negative cloud-to-ground flash count and the monthly mean maximum temperature during the months of August, 1999 to 2006.<br>
(a) The whole Switzerland, (b) within 100 km of the Säntis Mountain