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UNIVERSITY OF BUCHAREST
FACULTY OF PHYSICS Guest
2024-11-23 18:33 |
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Conference: Bucharest University Faculty of Physics 2014 Meeting
Section: Atmosphere and Earth Science; Environment Protection
Title:
Electrical characteristics associated with lightnings detected by SAFIR network during 2003-–2007 in Romania
Authors:
D. CARBUNARU, S.BURCEA
Affiliation:
National Meteorological Administration, Bucharest, Romania
E-mail
daniel.carbunaru@meteoromania.ro
Keywords:
lightning, convection, spatial distribution
Abstract:
One of the fundamental physical phenomena characteristic to convective systems are electrical events asociated with the presence of both positive and negative charges (electrical dipole or electrical tripole configurations) inside the clouds, and with their redistribution by electrical discharging (lightning) from cloud to cloud or from cloud to ground. To highlight some of the physical properties associated with lightning in Romania and its vicinity, data recorded with National Lightning Detection Network (SAFIR type) in 2003, 2004, 2005 and 2007 (January–December) were analyzed. Depending on the lightning polarity (positive or negative), the following parameters were investigated: lightning multiplicity (number of electric discharge in the lighting channel), total lightning duration (ms), lightning energy (kJ), integral of action (specific energy associated with Joule efect in the objects hit by lightning, kJ), maximum electrical current from the first discharge (kA), maximum variation of electric current in the first discharge (kA/μs), time taken to half decrease of the maximum intensity during the first discharge (μs). For all teh above mentioned parameters, percentage and spatial distributions were obtained. First it was observed that positive lightning energy has higher values than negative ones. These values are associated with higher electric intensity of the first channel discharge and whit a higher action integral (stable electrical current between consecutive discharges in lightning channel). On the other hand, negative lightning has higher multiplicity than the positive ones, and large variations of electrical intensity in the channel with amplified induction effect in the ground objects. The spatial distributions characteristics associated with lightning parameters were also highlighted.
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