摘要
根据远离平衡的复杂系统演化的雪崩性和自相似倍增串级性,强调了多重分形工具的重要;利用青藏高原中部地区雷暴放电的地面电场仪资料,基于多重分形谱的小波估计方法,对强放电前雷电活动的多重分形特征进行了分析,发现多重分形谱可用推广的多重分形二项倍增串级模式描述,强放电前放电过程具有强烈的奇异性和明显的多重分形性,谱宽度Δα>1·6,最小标度指数αmin<-0·3;随着放电的活跃,Δα表现出明显的增加,而强的放电则发生在随后Δα的高值区或下降区,并对相关的原因进行了讨论.
It is considered that complex systems far from equilibrium are evolved in avalanche and self similar multiplicative cascade way, and have characteristics of multifractality. By using the ground electric field data obtained in the middle of Qinghai-Xizang plateau region, multifractal behavior of lightning discharges in thunderstorm is investigated with wavelet-based muhifractal method. It is found that strong singularity and mulffractality are involved in the strong lightning discharges, the minimum exponent αmin, is less than - 0.3, and the width of spectrum Aa is greater than 1.6, and the scaling behavior is consistent with the modified version of the binomial multiplicative cascade multifractal model. It is also shown that △α increases with the enhancing of the discharge activity, and strong lightning happens in regions where △α is high or is decreasing, the related reason is discussed.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2006年第2期957-961,共5页
Acta Physica Sinica
基金
国家自然科学基金(批准号:40375004)资助的课题.~~
关键词
多重分形
雪崩
倍增串级
小波
闪电放电
muhifractal, avalanche, multiplicative cascade, wavelet, lightning discharge