Where Are the Lightning Hotspots on Earth?

Abstract

Previous total lightning climatology studies using Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) observations were reported at coarse resolution (0.5°) and employed significant spatial and temporal smoothing to account for sampling limitations of TRMM’s tropical to subtropical low-Earth-orbit coverage. The analysis reported here uses a 16-yr reprocessed dataset to create a very high-resolution (0.1°) climatology with no further spatial averaging. This analysis reveals that Earth’s principal lightning hotspot occurs over Lake Maracaibo in Venezuela, while the highest flash rate density hotspot previously found at the lower 0.5°-resolution sampling was found in the Congo basin in Africa. Lake Maracaibo’s pattern of convergent windflow (mountain–valley, lake, and sea breezes) occurs over the warm lake waters nearly year-round and contributes to nocturnal thunderstorm development 297 days per year on average. These thunderstorms are very localized, and their persistent development anchored in one location accounts for the high flash rate density. Several other inland lakes with similar conditions, that is, deep nocturnal convection driven by locally forced convergent flow over a warm lake surface, are also revealed. Africa is the continent with the most lightning hotspots, followed by Asia, South America, North America, and Australia. A climatological map of the local hour of maximum flash rate density reveals that most oceanic total lightning maxima are related to nocturnal thunderstorms, while continental lightning tends to occur during the afternoon. Most of the principal continental maxima are located near major mountain ranges, revealing the importance of local topography in thunderstorm development.

La interdisciplinariedad en la ciencia del rayo

“…La más reciente publicación de resultados de medición satelital de la NASA (Albrecht, 2016) muestra, por ejemplo, que el sitio de mayor actividad de rayos del mundo estaría ubicado en la región del Catatumbo y específicamente en el lago de Maracaibo y de las 10 poblaciones de mayor actividad de rayos en la zona de Suramérica, 7 están ubicadas en Colombia. La actividad de rayos en esta región llevó a Alexander von Humboldt (Humboldt, 1956) a llamar este fenómeno como el "rayo del Catatumbo".…”

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

“…According to several studies about the lightning climatology around the Earth, the Congo Basin is considered as the most active region with either a large maximum or two distinct ones (Christian et al, 2003;Williams and Sátori, 2004;Albrecht et al, 2011Albrecht et al, , 2016Cecil et al, 2014;Soula et al, 2016). Actually, the features of the maximum area depend on the spatial resolution considered in the calculation of the flash rate density (FRD) and the scale resolution in the graphic representation.…”

“…Actually, the features of the maximum area depend on the spatial resolution considered in the calculation of the flash rate density (FRD) and the scale resolution in the graphic representation. Albrecht et al (2016) performed a very detailed analysis of FRD thanks to Lightning Imaging Sensor (LIS) data around the Earth by using several spatial resolutions. They showed the features of the maxima FRD strongly depend on the spatial resolution and on the duration of the period considered for the study.…”

“…Thus, the location and the value of the first-and second-ranked maxima FRD stabilize when the period is longer. With the better resolution (0.1 • ) used in Albrecht et al (2016), the second-ranked hotspot is always located around [28 • E, 2 • S] from 5 years of data. Furthermore, they showed most of the first 10 lightning hotspots over the entire African continent, including the strongest ones, are located in Democratic Republic of Congo (DRC).…”

Climatic Projections of Lightning in Southeastern Brazil Using CMIP5 Models in RCP’s Scenarios 4.5 and 8.5

“…Over the years, several studies using different methodologies [3] [4] [5] [6], have already shown that the Southeast Region of Brazil is inserted in the spatial context of the regions of the world with the highest incidence of this phenomenon. Only in the State of São Paulo, there are around 700,000 lightning per year [1].…”