Journal metrics

Journal metrics

  • IF value: 2.281 IF 2.281
  • IF 5-year value: 2.693 IF 5-year 2.693
  • CiteScore value: 2.43 CiteScore 2.43
  • SNIP value: 1.193 SNIP 1.193
  • SJR value: 0.965 SJR 0.965
  • IPP value: 2.31 IPP 2.31
  • h5-index value: 40 h5-index 40
  • Scimago H index value: 73 Scimago H index 73
Volume 18, issue 2 | Copyright
Nat. Hazards Earth Syst. Sci., 18, 479-489, 2018
https://doi.org/10.5194/nhess-18-479-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 3.0 License.

Research article 13 Feb 2018

Research article | 13 Feb 2018

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

Jean K. Kigotsi1,2, Serge Soula1, and Jean-François Georgis1 Jean K. Kigotsi et al.
  • 1Laboratoire d'Aérologie, Université de Toulouse, CNRS, Toulouse, France
  • 2Département de Physique, Faculté des Sciences, Université de Kinshasa, Kinshasa, Democratic Republic of Congo

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) of the Congo Basin is made with data obtained by the World Wide Lightning Location Network (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 rate density (FRD) with maximums in a ratio of 1.94 and 2.59 for 2012 and 2013, respectively. The FRD is much more widely distributed in Area_sec, which means the whole area contributes more or less equal to the lightning activity. 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 09:00UTC and between 16:00 and 17:00UTC, respectively. In Area_sec the proportion of days with low lightning rate (0–1000 flashes per day) is much larger (∼ 45% in 2013) compared to Area_max (∼ 23% in 2013). In Area_max the proportion of days with moderate lightning rate (1001–6000 flashes per day) is larger (∼ 68.5% in 2013) compared to Area_sec (∼ 46% in 2013). The very intense convective events are slightly more numerous in Area_sec. In summary, the thunderstorm activity in Area_sec is more variable at different scales of time (annually and daily), in intensity and in location. Area_max combines two favourable effects for thunderstorm development, the convergence associated with the African easterly jet of the Southern Hemisphere (AEJ-S) and a geographic effect due to the orography and the presence of a lake. The location of the strong convection in Area_sec is modulated by the distance of westward propagation/regeneration of mesoscale convective systems (MCSs) in relation to the phase of Kelvin waves.

Download & links
Publications Copernicus
Download
Short summary
The thunderstorm activity in the Congo Basin is known as the highest in the world. This paper compares the lightning flash count in two 5° × 5° areas from this region. One area in eastern Democratic Republic of Congo experiences a sharp maximum of the lightning flash density whatever the year and at any period of the year, and a very pronounced daily cycle. However, the area in the centre of the Congo Basin exhibits a lightning flash activity much more variable in location and time.
The thunderstorm activity in the Congo Basin is known as the highest in the world. This paper...
Citation
Share