Comparison of lightning activity in the two most active areas of the Congo Basin

Abstract

Abstract. A comparison of the lightning activity in the two most active areas (Area_max for the main maximum and Area_sec for the secondary maximum) in the Congo Basin is made with data obtained by the WWLLN during 2012 and 2013. Both areas of same size (5° × 5°) exhibit flash counts in a ratio of about 1.32 for both years and very different distributions of the flash density with maximum in a ratio of 1.941 and 2.585 for 2012 and 2013, respectively. The diurnal cycle is much more pronounced in Area_max than in Area_sec with a ratio between the maximum and the minimum of 15.4 and 4.7, respectively. However, the minimum and maximum of the hourly flash rates are observed roughly at the same time in both areas, between 07:00 and 09:00 UTC and between 16:00 and 17:00 UTC, respectively. In Area_sec the number of days with very low activity (0–1000 flashes per day) is very large (164 days) and that with larger activity decreases very rapidly. In Area_max the number of day decreases more slowly and is larger for most of levels of lightning activity. The correlation at the daily scale between the lightning activity in Area_max and that in Area_sec is weak but positive. In summary, the thunderstorm activity in Area_sec is more variable at different scales of time (monthly and daily), in intensity and in location.