Lightning

Abstract

The previous review of U.S. lightning research for the IUGG covered the period 1971–1975 and was published by Uman et al. (1975). Although the present review is intended to cover the research of the last four years, 1979–1982, we will survey the total seven year period, 1976–1982, since the previous review. References to 82 articles were included in the 1971–1975 review, an average of 16 to 17 papers per year. Interestingly enough, the yearly average for 1976–1982 is 18, a value almost identical to the previous period. Many of these recent articles describe research performed as part of the Thunderstorm Research International Program (TRIP) hosted by the NASA Kennedy Space Center (KSC), Florida in 1976–1978 and by the New Mexico Institute of Mining and Technology in Socorro, New Mexico in 1979–1982.

Modeling and decoding event-based sensor lightning response

“…All three flashes have stepped leaders propagating from the cloud to the ground followed by a return stroke from the ground up to the clouds. 20 NLDN recorded positive Intra-cloud flashes for R2 and R3. When the Phantom camera saturates the DN for the saturated pixel is maxed at 4096.…”

Spatial Structure of Lightning and Precipitation Associated with Lightning-Caused Wildfires in the Central to Eastern United States

“…The positive flash count is less strongly peaked than the total flash count because positive flashes are more likely to originate in the anvil rather than the core [25]. Positive flashes are rarer than negative flashes but tend to have longer-lasting current flows, thus assumed to be more likely to ignite fires [10,11]. In Figure 6, the ignitions per flash in the vicinity of each ignition are shown.…”

“…But to explain why a similar drop is not seen in the positive flash count will require a deeper examination of the storm structure, as carried out in the next section. Positive flashes are rarer than negative flashes but tend to have longer-lasting current flows, thus assumed to be more likely to ignite fires [10,11]. In Figure 6, the ignitions per flash in the vicinity of each ignition are shown.…”

“…Flash ignition is also dependent on the current magnitude and duration, and it is commonly assumed that a long continuing current (LCC) is necessary for ignition [9]. Positive flashes are four times more likely to have an LCC than negative flashes [10,11], so should be more likely to cause ignitions, yet the literature shows mixed results. For Fire 2023, 6, 262 2 of 15 example, Anderson [9] modeled wildfire ignitions based on the assumption that only LCC would ignite fires and found correlation coefficients ranging from 0.3 to 0.76, though other complicating variables, such as rainfall, moisture content, and survival time, were modeled rather than observed.…”

Localization and quantification of the acoustical power of lightning flashes

“…Les éclairs peuvent être décrits par de nombreuses variables, notamment leur énergie totale par unité de longueur (E l ) appelée aussi énergie injectée, qui est utilisée dans les modèles théoriques et numériques de tonnerre [Few et al, 1967;Few, 1970;Lacroix et al, 2019] décrits dans la section 1. [Plooster, 1971;Borovsky, 1998] à 20 000 J.cm −1 [Uman, 1987].…”