闪电过程中电磁辐射功率的变化特征

利用无狭缝摄谱仪获得的地闪回击光谱，结合同步电场资料，计算了一次闪电放电过程中的通道温度、电导率、回击电流峰值、通道光亮度和电磁功率峰值等参数，均在文献报道的合理范围内。并由此讨论了回击前截止时间、回击通道光亮度及电磁功率峰值之间的相关性，研究了放电通道的电导率、电流和电磁功率之间的变化关系。结果表明：回击前截止时间越长，回击过程中所中和的电荷越多，形成的电流越大，辐射出的电磁能量越大。当通道电导率变大，同时电场变化峰值也增大时，通道内电流变大，回击过程中辐射出的电磁功率也变大。这方面的工作为计算闪电放电过程中产生的光学能量和电磁能量提供一定的参考依据。

Evolution Characteristics of Electromagnetic Power Radiated in Lightning Discharge Processes

Combining the spectra of could-to-ground lightning discharge processes obtained by a slit-less spectrograph with synchronous electric field information, the temperature, the conductivity, the current peak, electromagnetic power peak and the luminance of the discharge channel are calculated. The values are in a normal range reported by references. The correlation among cut-off time before a subsequent return stroke, the luminance and electromagnetic power peak of the channel is discussed. The change trends of the conductivity, the current peak and electromagnetic power peak are also investigated. The results show when cut-off time is long, neutralized charges will grow, the current will rise and electromagnetic power radiated from the channel will increase. When the conductivity and the peak of the electric field change increase simultaneously, the current in the channel will rise and electromagnetic power radiated from the channel will be greater. This work will provide some references for calculating optical and electromagnetic energy radiated by lightning discharge processes.