The rate of neutralized charge by lightning(RNCL) is an important parameter indicating the intensity of lightning activity.The total charging rate(CR),the CR of one kind of polarity(e.g.,negative) charge(CROP)...The rate of neutralized charge by lightning(RNCL) is an important parameter indicating the intensity of lightning activity.The total charging rate(CR),the CR of one kind of polarity(e.g.,negative) charge(CROP),and the outflow rate of charge on precipitation(ORCP) are proposed as key factors impacting RNCL,based on the principle of conservation of one kind of polarity charge in a thunderstorm.In this paper,the impacts of updraft on CR and CROP are analyzed by using a 3D cloud resolution model for a strong storm that occurred in Beijing on 6 September 2008.The results show that updraft both promotes and inhibits RNCL at the same time.(1) Updraft always has a positive influence on CR.The correlation coefficient between the updraft volume and CR can reach 0.96.Strengthening of the updraft facilitates strengthening of RNCL through this positive influence.(2) Strengthening of the updraft also promotes reinforcement of CROP.The correlation coefficient between the updraft volume and CROP is high(about0.9),but this promotion restrains the strengthening of RNCL because the strengthening of CROP will,most of the time,inhibit the increasing of RNCL.(3) Additionally,increasing of ORCP depresses the strengthening of RNCL.In terms of magnitude,the peak of ORCP is equal to the peak of CR.Because precipitation mainly appears after the lightning activity finishes,the depression effect of ORCP on RNCL can be ignored during the active lightning period.展开更多
基金Supported by the National Natural Science Foundation of China(41205001)National(Key)Basic Research and Development(973)Program of China(2014CB441406)+1 种基金National Major Scientific Instruments and Equipment Development Special(61327810)Basic Research Funds of CAMS(2012Y005 and 2013Z006)
文摘The rate of neutralized charge by lightning(RNCL) is an important parameter indicating the intensity of lightning activity.The total charging rate(CR),the CR of one kind of polarity(e.g.,negative) charge(CROP),and the outflow rate of charge on precipitation(ORCP) are proposed as key factors impacting RNCL,based on the principle of conservation of one kind of polarity charge in a thunderstorm.In this paper,the impacts of updraft on CR and CROP are analyzed by using a 3D cloud resolution model for a strong storm that occurred in Beijing on 6 September 2008.The results show that updraft both promotes and inhibits RNCL at the same time.(1) Updraft always has a positive influence on CR.The correlation coefficient between the updraft volume and CR can reach 0.96.Strengthening of the updraft facilitates strengthening of RNCL through this positive influence.(2) Strengthening of the updraft also promotes reinforcement of CROP.The correlation coefficient between the updraft volume and CROP is high(about0.9),but this promotion restrains the strengthening of RNCL because the strengthening of CROP will,most of the time,inhibit the increasing of RNCL.(3) Additionally,increasing of ORCP depresses the strengthening of RNCL.In terms of magnitude,the peak of ORCP is equal to the peak of CR.Because precipitation mainly appears after the lightning activity finishes,the depression effect of ORCP on RNCL can be ignored during the active lightning period.