Characterization of M components and leaders of natural lightning from high-speed video observations and atmospheric electric field measurements

• Grant number: 10/02716-5
• Support Opportunities: Scholarships in Brazil - Master
• Effective date (Start): August 01, 2010
• Effective date (End): February 29, 2012
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geophysics
• Principal Investigator: Marcelo Magalhães Fares Saba
• Grantee: Leandro Zanella de Souza Campos
• Host Institution: Instituto Nacional de Pesquisas Espaciais (INPE). Ministério da Ciência, Tecnologia e Inovação (Brasil). São José dos Campos , SP, Brazil

Abstract

This research project consists in combining observations obtained through high-speed cameras and atmospheric electric field measurements in order to study two physical phenomena involved in the production of natural cloud-to-ground lightning: M components (pulses that occur during the continuing current and whose peak current value, obtained from triggered lightning experiments, can range from hundreds to a few thousands of amperes) and leaders (responsible for ionizing and making the lightning channel conductive). We intend to use a previously developed software to obtain luminosity-versus-time curves of each flash from the video recordings and correlate these data with "slow" electric field measurements (whose integrator circuit has a longer time decay constant) in order to estimate intensity-related parameters of M components. We also expect to be able to correlate data on the development of leaders by observing them simultaneously through the cameras and the "fast" electric field sensors (whose time decay constant is shorter) in order to analyze their fine structure and obtain qualitative and quantitative relations between the data provided by both instruments. After characterizing these phenomena from the data provided by the instruments, we expect to be able to analyze in a critical way the existing physical models developed to describe and explain them, proposing eventual revisions or reformulations that might be necessary.

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

CAMPOS, LEANDRO Z. S.; SABA, MARCELO M. F.. Visible channel development during the initial breakdown of a natural negative cloud-to-ground flash. Geophysical Research Letters, v. 40, n. 17, p. 4756-4761, SEP 16 2013. (10/02716-5, 03/08655-4)

CAMPOS, LEANDRO Z. S.; SABA, MARCELO M. F.; KRIDER, E. PHILIP. On 2 stepped leaders in negative cloud-to-ground lightning. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, v. 119, n. 11, p. 6749-6767, JUN 16 2014. (10/02716-5, 03/08655-4)

CAMPOS, LEANDRO Z. S.; SABA, MARCELO M. F.; WARNER, TOM A.; PINTO, JR., OSMAR; KRIDER, E. PHILIP; ORVILLE, RICHARD E.. High-speed video observations of natural cloud-to-ground lightning leaders - A statistical analysis. ATMOSPHERIC RESEARCH, v. 135, p. 285-305, JAN 2014. (10/02716-5, 03/08655-4)