Study On The Correlation Between Thermodynamic Property And Discharge Characteristic In The Lightning Channel

The spectra of cloud-to-ground (CG) lightning discharge plasma captured by aSlit-less spectrograph in Qinghai plateau of China, the temperature and the electron densityin lightning discharge channel which are the parameters of thermodynamic property havebeen obtained according to the spectral analysis. The spectral structure and temperatureshow that there are obvious differences among the spectral structure of every return strokeeither in different lightning or one lightning, and the difference of spectral structure reflectthe thermodynamic property. The channel temperature varies significantly from stroke tostroke in a given lightning, and the temperature is not correlation with the happening ofreturn strokes order.The synchronous electrical information of lightning discharge plasma is recorded bythe fast antenna and slow antenna systems. The radiated electric field of every return strokeis obtained by the electrical data, and then the peak value of current and its action integralare calculated. The results of the current and its action integral are compared with literaturevalues, and there are in satisfactory agreement. Meanwhile, the analyzed dischargecharacteristic of lightning indicate that the radiated electric field of first return stroke innegative CG lightning is the strongest, the corresponding peak discharge current of firstreturn stroke is also stronger than the subsequent return strokes. But it is also frequent thatthe discharge of subsequent return stroke is stronger than the first return stroke.The relationship between thermodynamic property and the discharge characteristic isof great importance to further reveal the physical mechanism in the lightning dischargeprocesses. Combining the spectra and electrical data, the relationship between spectralstructure and discharge characteristic has been analyzed firstly in different strokes of oneCG lightning. The result indicates that the total intensity of spectra is positive correlation tothe discharge current. Then the relationship between thermodynamic property anddischarge characteristic has been analyzed in detail, the results indicate that the plasmatemperature is in direct proportion to the action integral in the first return strokes ofdifferent CG lightning. But in different strokes of one CG lightning, the temperature andthe action integral appear a non-positive correlation. It can be inferred from the analysisthat the current of every return stroke can be compared by the total intensity of spectra forone lightning with multiple return strokes and the energy transmission can be diagnosed according to the channel temperature in the first return strokes of different lightning. Theresults in this work will give some referenced date for the study on the energy transmissionand generation of oxynitride in lightning process, and also provide a theoretical basis forthe research of lightning physics and lightning protection.