Climatology of large peak current cloud‐to‐ground lightning flashes in southeastern Brazil

Abstract

[1] The goal of this article is to present the first climatology of large peak current cloud-toground (LPCCG) flashes in southeastern Brazil, in terms of flash density, percentage of positive LPCCG flashes, peak current, and diurnal distributions. The results are based on data provided by the Brazilian Lightning Detection Network (BrasilDat) from 1999 to 2006, and only flashes with peak currents >75 kA recorded during the months of December, January, February, and March (the approximate summer season in the Southern Hemisphere) were considered in order to compare with similar data obtained by Lyons et al. (1998) in the contiguous United States. The LPCCG data set, consisting of approximately 122,000 flashes, is currently the largest data set available for the tropical region. The LPCCG flashes represent about 3% of all flashes recorded during this period. All LPCCG distributions were obtained for both negative and positive flashes. The flash density distributions for negative and positive LPCCG flashes are different and furthermore differ from the flash density distributions for all negative and positive cloud-to-ground (CG) flashes. This suggests that the flash density distribution of CG flashes is peak current dependent. While the negative LPCCG flash density distribution has no significant dependence on any specific geographical or meteorological feature, the positive LPCCG flash density distribution and the distribution of the percentage of positive LPCCG flashes are closely related to the occurrence of mesoscale convective systems. The peak current and diurnal distributions of LPCCG flashes were found to be similar to those obtained in the contiguous United States.

A decade of cloud‐to‐ground lightning in Canada: 1999–2008. Part 2: Polarity, multiplicity and first‐stroke peak current

“…this value is lower than the values calculated from observations by Lyons et al (1998a) and Pinto et al (2009), 5.4 and 2.8, respectively. Negative LCLFs in Canada are less numerous for peak currents > 200 kA (average ratio of 0.6), compared to the findings of Lyons et al (1998a) and Pinto et al (2009), 4.1 and 1.1, respectively. LCLFs with stroke multiplicity ≥10 are primarily associated with negative CG flashes and detected in all seasons except winter (table 2).…”

Climatology of lightning activity in South China and its relationships to precipitation and convective available potential energy

“…However, for the positive LPCCG lightning, two high-concentration regions, one around the mouth of the Pearl River and the other to the north of the Leizhou Peninsula, are connected by a belt of scattered high-density lightning locations. Differences between positive and negative LPCCG lightning densities have also been reported by Lyons et al (1998) and Pinto et al (2009). Table 2 lists the average lightning density over land and offshore regions, including the ratios of the average density over land to that over water.…”

“…In previous studies (e.g., Cummins et al, 1998), positive CG (PCG) lightning flashes with currents of <10 kA were removed from the data as they might be a misinterpretation of cloud lightning. Furthermore, following the subjective definition of Lyons et al (1998) and Pinto et al (2009) of LPCCG lightning, the CG lightning with an absolute peak (Lyons et al, 1998), and a ratio of 3% has been reported over southeastern Brazil (Pinto et al, 2009). High Resolution Full Climatology TRMM/Lightning Imaging Sensor (LIS) 0.5 • data were used to determine the total lightning activity in the study region.…”

“…In addition to the above considerations, we were further concerned with occurrences of large peak-current CG (LPCCG) lightning (peak currents of >75 kA) and the possible contrast between CG lightning activity over land and over offshore waters. LPCCG lightning, because of its destructiveness and association with sprites and elves in the stratosphere and mesosphere, has been of particular concern in the research community (e.g., Lyons et al, 1998;Kochtubajda et al, 2006;Pinto et al, 2009). In addition, the landoffshore lightning comparison provides another perspective from which to understand the impact of underlying surfaces on convective activity and lightning discharge.…”

A comparative study of negative cloud‐to‐ground lightning characteristics in São Paulo (Brazil) and Arizona (United States) based on high‐speed video observations

“…Lightning has been the object of many studies since the end of the nineteenth century, beginning with recordings using still cameras [ Hoffert , 1888], followed by the use of time‐resolved photography, instrumented towers, video cameras, lightning locating and mapping systems, triggered lightning facilities, and, more recently, satellite optical sensors. Lightning characteristics based on these techniques have been published by many authors [e.g., Rakov et al , 1994; Diendorfer et al , 1998, 2002; Valine and Krider , 2002; Pinto et al , 2003; Rakov and Huffines , 2003; Schulz et al , 2005; Hussein et al , 2006; Miki et al , 2006; Pinto et al , 2006; Biagi et al , 2007; Pinto et al , 2007; Flache et al , 2008; Pinto et al , 2009]. Recently, high‐speed video cameras have added much to our understanding of natural downward lightning physics [e.g., Ballarotti et al , 2006; Kong et al , 2008; Saba et al , 2008; Campos and Saba , 2009; Saba et al , 2009].…”