Inferred long term trends in lightning activity over Africa

Global warming is becoming a reality, with growing evidence that anthropogenic activity on our planet is starting to influence our climate (IPCC, 2001). Due to the increase in significant weather-related disasters in recent years, it is important to investigate the role of global warming on such changes. In this paper we attempt to estimate the long term trends in lightning activity over tropical Africa during the past 50 years, using upper tropospheric water vapor as a proxy for regional lightning activity. We use the NCAR/NCEP reanalysis product available for the period 1948 to the present to estimate the long term trends in lightning activity. Similarity between the long term African lightning variability and observed rainfall and river discharge variability are demonstrated. Since 1950 the inferred lightning activity over Africa shows significant variability, reaching a maximum during the 1960s, followed by a decrease in activity during the following 30 years.