Estimation of...Location Data_Qi LI.pdf

Estimation of Lightning-Generated NOx in the Mainland of ChinaBased on Cloud-to-Ground Lightning Location DataQi LI1,2,Fengxia GUO*1,Xiaoyu JU3,Ze LIU1,Mingjun GAN1,Kun ZHANG1,and Binbin CAI11Key Laboratory of Meteorological Disaster,Ministry of Education(KLME)/Joint International Research Laboratory ofClimate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation ofMeteorological Disasters(CIC-FEMD)/Key Laboratory for Aerosol-Cloud-Precipitation of China MeteorologicalAdministration,Nanjing University of Information Science&Technology,Nanjing 210044,China2Huangshi Meteorological Bureau,Huangshi 435002,China3Anhui meteorological disaster prevention center,Hefei 230061,China(Received 18 August 2021;revised 19 April 2022;accepted 19 May 2022)ABSTRACTLightning-generated nitrogen oxides(LNOx)have a major influence on the atmosphere and global climate change.Therefore,it is of great importance to obtain a more accurate estimation of LNOx.The aim of this study is to provide areference for the accurate estimation of the total LNOx in the mainland of China based on cloud-to-ground lightning(CG)location data from 2014 to 2018.The energy of each CG flash was based on the number of return strokes per CG flash,thepeak current of each return stroke,and the assumed CG breakdown voltage.The energy of intracloud lightning(IC)wasbased on the estimated frequencies of IC and the assumed energy of each IC flash.Combining the energy of lightning andthe number of nitric oxide(NO)molecules produced by unit energy(no),the total LNOx production in the mainland ofChina was determined.The LNOx in the mainland of China estimated in this study is in the range(0.1570.321)109 kg peryear Tg(N)yr1,which is on the high end of other scholars works.Negative cloud-to-ground lightning(NCG)flashesproduce the most moles of NOx,while positive cloud-to-ground lightning(PCG)flashes produce the least total moles ofNOx.The breakdown voltage of PCG is greater than that of IC or NCG,while the latter has a greater output of LNOx.Key words:cloud-to-ground lightning location,lightning peak current,lightning breakdown voltage,nitrogen oxide(NOx)Citation:Li,Q.,F.X.Guo,X.Y.Ju,Z.Liu,M.J.Gan,K.Zhang,and B.B.Cai,2023:Estimation of lightning-generatedNOx in the mainland of China based on cloud-to-ground lightning location data.Adv.Atmos.Sci.,40(1),129143,https:/doi.org/10.1007/s00376-022-1329-6.Article Highlights:Based on cloud-to-ground lightning(CG)location data,the energy of each CG flash and the frequencies of intracloudlightning(IC)were estimated.The lightning-generated nitrogen oxides(LNOx)estimation for the mainland of China is between 0.157 Tg(N)yr1 and0.321 Tg(N)yr1,which is on the high end of other studies.Compared to positive cloud-to-ground lightning,intracloud lightning and negative cloud-to-ground lightning havegreater output of lightning-generated nitrogen oxides.1.IntroductionNitrogen oxides (NOx)are important to troposphericchemistry due to their role as a precursor of ozone (O3)(Crutzen,1974).It should be noted that NO2 is the chemicalexpression for nitrogen dioxide.In addition,NOx can controlconcentrations of tropospheric hydroxyl radical (OH),thereby partially controlling the level of oxidants.NOx canarise from both anthropogenic and natural emission sources.The anthropogenic sources of NOx are largely known.How-ever,lightning-generated nitrogen oxides (LNOx)are stillthe source with the greatest uncertainty.In the troposphere,lightning is the largest naturalsource of NOx(Bucsela et al.,2010);however,estimates ofLNOx and its efficiency(LNOx per flash)are still quite uncer-tain(Beirle et al.,2010).Many researchers have conductedstudies focused on improving estimates of the total amount*Corresponding author:Fengxia GUOEmail:ADVANCES IN ATMOSPHERIC SCIENCES,VOL.40,JANUARY 2023,129143 Original Paper Institute of Atmospheric Physics/Chinese Academy of Sciences,and Science Press and Springer-Verlag GmbH Germany,part of Springer Nature 2023of LNOx(mainly LNO).By measuring the NOx generated inlaboratory long-gap discharge experiments,researchershave been able to estimate LNOx and extrapolate globalLNOx(Peyrous and Lapeyre,1982;Wang et al.,1998;Cooray et al.,2009).There are several problems with thismethod.First,the peak current and the energy of laboratorydischarges are much smaller than those of natural lightning.Second,water vapor,relative humidity,and other environmen-tal parameters also influence lightning development,but inlaboratory long-gap discharge experiments,these influencesare usually neglected.These factors bring great uncertaintyto the estimation of LNOx,and the results obtained by differ-ent researchers vary greatly.Most estimates of global LNOxproduction range from 28 Tg(N)yr1(Schumann andHuntrieser,2007).At present,there are few studies on LNOx estimationfor the mainland of China.Zhou and Qie(2002)extrapolatedthe total LNOx emissions in the mainland of China to be0.384 Tg(N)yr1 using the cloud-to-groun