The Development And Fractal Feature Of Lightning Based On VHF Locating Data

The internal structure of the lightning and its process of development is the main work in the lightning research.In this article we describe the IC lightning in Colorado and the CG lightning in Alabama in details by using the LMA locating system.Lightning exhibits both fractal and avalanche behavior as many other variety phenomena in geophysics.Following the recent research results of Mandelbrot's fractal,we study the self-organized evolution characters of the fractal and avalanche in lightning discharge in this dissertation. The mian contributions of paper are:In the first chapter, we mainly introduce some basic knowledges of the lightning and the common knowledges of fractal.Due to the instantaneity and half randomness of lightning, conventional research methods have been unable to truly know it.The rising of the study of contemporary complexity on the basis of the fractal geometry of Mandelbrot undoubtedly points out the new path to lightning research.Hence the fractal method to explain the characteristics of lightning.In the second chapter, we focuse on the charge characteristics of lightning and give specific description of lightning morphology.We describe IC lightning in Colorado and CG lightning in Alabama in details by using the LMA locating system.It turns out that the development of the lightning shows double layer structure. And discharge of IC lightning begins with negative breakdown process that is in the upward development, then shows the double level of development. The initial breakdown of CG lightning arises on the central region of negative charge, then develops downwards. Continuing to develop downwards after neutralizing the positive charge under it, it ends with foring the discharge towards ground. Except for the discharge towards ground in vertical direction, CG lightning also develop with a double-layer structure in horizontal direction.In the third chapter, we analyze the lightning discharge process in fractal method.We use the data monitored in LDAR system to perform DFA about the density of lightning in a thunderstorm, getting a result that the Hurst index is greater than 0.5.This means that the density of lightning in a thunderstorm presents long-range correlation.