Lightning Geolocation and Classification During the RELAMPAGO Field Campaign
Journal Article
Overview
abstract
Severe weather forecasting is an important tool for mitigating damages; brought by intense lightning, large hail, heavy precipitation, strong; winds, or tornadoes during thunderstorms, yet the reliability of such; forecasts suffers from our limited understanding of the severe weather; generative processes inside thunderclouds. With an increasing knowledge; of the occurrence context of distinct types of lightning within storms,; lightning remote sensing may elucidate the kinematic and microphysical; environment where severe weather initiates. In particular, distinct; energetic intra-cloud (IC) lightning discharges, compact intra-cloud; lightning discharges [CID; e.g., Nag and Rakov, 2010] and energetic; intra-cloud pulses [EIP; e.g., Lyu et al., 2015], have been shown to; have different occurrence contexts, making them strong candidates for; thunderstorm remote sensing research. In this study, observations from; the RELAMPAGO field campaign in Argentina (November 1 to December 12th; 2018) are used to determine lightning flash rates and the prevalence of; different energetic lightning types in RELAMPAGO storms, enabling; further research on the link between lightning activity and severe; weather production inside thunderstorms.Lightning events during; RELAMPAGO were observed by a deployed array of four Low-Frequency (LF,; ~1-400 kHz) radio receivers. Using time of arrival,; magnetic direction finding, and peak amplitude for each observed event; at different stations, lightning source locations are estimated using a; statistical least squares filter, along with clock and site errors; associated with the receivers. Return stroke peak current for each event; is also estimated in the filter, using an atmospheric attenuation; observation model. The energetic lightning events in the campaign are; then classified automatically between cloud-to-ground (CG), IC, CID or; EIP, following an improved parametrization scheme originally proposed by; Lyu et al. [2015]. In this paper we present the geolocation and; classification of RELAMPAGO lightning events, and we also provide an; analysis of lightning flash rates during the campaign. A few individual; thunderstorm case studies are also discussed, which are augmented by; other meteorological data from dual-polarimetric radar, hailpads, and; other sources.
