Intraregional Comparisons of the Near‐Storm Environments of Storms Dominated by Frequent Positive Versus Negative Cloud‐to‐Ground Flashes

Abstract

• Storms dominated by frequent positive or negative ground flashes were mined from 11 years of National Lightning Detection Network data. • The near-storm environments of storms dominated by frequent positive or negative ground flashes were compared in each of seven regions. • The combination of environmental parameters inferred to have produced storms with anomalous charge structure varied from region to region.

The Relation of Environmental Conditions With Charge Structure in Central Argentina Thunderstorms

“…Environmental characteristics such as the temperature, humidity, CCN concentration, and wind field are fundamental in inducing cloud formation, microphysical processes, and kinematic motion within a cloud. These processes, in turn, affect hydrometeor charging polarity and, at a larger scale, the regions of charge that are developed inside thunderstorms (Carey & Buffalo, 2007; Eddy et al., 2021; Fuchs et al., 2015; Smith et al., 2000). Exploring charge structures is crucial as it relates to storm severity (Carey & Rutledge, 1998; Lang & Rutledge, 2011; MacGorman & Burgess, 1994), it impacts the production of nitrogen oxides (DeCaria et al., 2005; Price et al., 1997), affects the global electric circuit (Davydenko et al., 2004), lightning safety (Curran et al., 2000), etc.…”

“…Also, large wind shear is thought to provide dynamical forcing for strong updrafts, contributing to the organization and longevity of storms, leading to anomalous charge structure storms (Carey & Buffalo, 2007). Low precipitable water integrated over the entire vertical depth would produce less rainwater loading of updrafts and thus stronger updrafts (Carey & Buffalo, 2007; Eddy et al., 2021; Emanuel, 1981; Knupp & Cotton, 1985), resulting in anomalous storms.…”

Examining Conditions Supporting the Development of Anomalous Charge Structures in Supercell Thunderstorms in the Southeastern United States

“…Not all of these environmental conditions have been observed simultaneously in documented anomalous storms nor do they consistently differentiate anomalous and normal storm environments (e.g., Carey & Buffalo, 2007;Chmielewski et al, 2018;Eddy et al, 2021;Lang & Rutledge, 2011). Rather, it is thought that only some combination and degree of these conditions may be required for ACS development (e.g., Carey & Buffalo, 2007;Chmielewski et al, 2018;Eddy et al, 2021;Lang & Rutledge, 2011).…”

“…Most thunderstorms with ACSs have been documented in the Great Plains and Midwest regions of the US (e.g., Bluestein & MacGorman, 1998; Branick & Doswell III, 1992; Carey & Buffalo, 2007; Carey et al., 2003; Chmielewski et al., 2018; Curran & Rust, 1992; Eddy et al., 2021; Fuchs et al., 2015, 2018; Gilmore & Wicker, 2002; Lang & Rutledge, 2002, 2006, 2011; Logan, 2018; Lyons et al., 1998; MacGorman & Nielsen, 1991; MacGorman & Burgess, 1994; Reap & MacGorman, 1989; Seimon, 1993; Smith et al., 2000; E. R. Williams et al., 2005), and therefore, most relationships between ACSs, thunderstorm structures, and environmental conditions have been derived from observations from those regions. Several studies examining contrasts between thunderstorm structures and environments in storms with ACSs and NCSs (i.e., “anomalous storms” and “normal storms”) have compared anomalous thunderstorms in the Great Plains with normal thunderstorms in the Eastern Atlantic and Southeastern US (Fuchs & Rutledge, 2018; Fuchs et al., 2016) and the tropics (Lang & Rutledge, 2002).…”

“…The size of cloud droplet populations has also been suggested to affect the sign of graupel charging, where it has been observed that smaller droplets favor positive charging of graupel (Avila & Pereyra, 2000). Not all of these environmental conditions have been observed simultaneously in documented anomalous storms nor do they consistently differentiate anomalous and normal storm environments (e.g., Carey & Buffalo, 2007; Chmielewski et al., 2018; Eddy et al., 2021; Fuchs et al., 2018; Lang & Rutledge, 2011). Rather, it is thought that only some combination and degree of these conditions may be required for ACS development (e.g., Carey & Buffalo, 2007; Chmielewski et al., 2018; Eddy et al., 2021; Fuchs et al., 2018; Lang & Rutledge, 2011).…”