一次强云对地闪电首次回击过程的光谱分析  

The Spectral Properties of an Intense Lightning Return Stroke

作　　者：袁萍[1] 郄秀书[2] 吕世华[2] 陈冠英[1] 张广庶[2] 

机构地区：[1]西北师范大学物理与电子工程学院,甘肃兰州730070 [2]中国科学院寒区旱区环境与工程研究所,甘肃兰州730000

出　　处：《光谱学与光谱分析》2006年第4期733-737,共5页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金(40475007);国家自然科学基金"十五"重点项目(40135010)资助

摘　　要：利用无狭缝光栅摄谱仪，获得了一次强云对地闪电首次回击过程400600m范围的光谱，将原子结构的理论应用于闪电光谱的研究，用多组态Dirac-Fock方法，计算了有关光谱线的波长、振子强度以及相应的激发态能量等参数，并重新辨认了波长为419．0和425．3nm的谱线。结合相应的光谱跃迁参数和电学观测资料对试验光谱进行了分析，并发现，回击通道的光谱结构及特性与闪电放电的强度密切相关，在强闪电回击过程中，激发能量较高的OⅡ离子谱线增强。根据光谱特征推断，强闪电回击通道的峰值温度应高于过去的估算值。The spectrum in the range of 400-600 nm from the first return stroke of an intense cloud-to-ground lightning flash was obtained by a slit-free spectrograph. Applying the atomic structure theory to the research work on lightning spectra, the wavelengths, oscillator strengths and excitation energies of upper levels were calculated for the transitions of related lightning spectrum. Multi-configuration Dirac-Fock method was employed in the calculation. From the results, re-identifications were carried out for the lines of 419.0 and 425.3 nm. It was found by spectral analysis combined with corresponding electrical information finds that the spectrum characteristic is closely related to the intensity of lightning discharge, as during an intense lightning return stroke the lines of O Ⅱ with high excitation energies are enhanced.

关 键 词：闪电光谱 等离子体 MCDF方法 

分 类 号：P427.3[天文地球—大气科学及气象学]