大气科学
大氣科學
대기과학
CHINESE JOURNAL OF ATMOSPHERIC SCIENCES
2015年
5期
941-952
,共12页
师正%谭涌波%唐慧强%杨忆%彭琳%郭秀峰%陈浩然
師正%譚湧波%唐慧彊%楊憶%彭琳%郭秀峰%陳浩然
사정%담용파%당혜강%양억%팽림%곽수봉%진호연
气溶胶%电荷结构%起电机制%闪电发生率%数值模拟
氣溶膠%電荷結構%起電機製%閃電髮生率%數值模擬
기용효%전하결구%기전궤제%섬전발생솔%수치모의
Aerosol%Charge structure%Charge separation mechanism%Flash rate%Numerical simulation
本文利用二维耦合气溶胶模块的雷暴云起电模式,结合一次南京雷暴个例,进行250 m分辨率雷暴云起电模拟实验,探讨了气溶胶浓度对雷暴云空间电荷分布以及闪电发生率的影响。在这个气溶胶模块中,假定一个三模态的气溶胶对数分布,考虑了气溶胶活化过程。结果显示:(1)随着气溶胶浓度增大,雷暴云电荷结构保持为三极型。(2)当气溶胶浓度从50 cm?3增加至1000 cm?3时,水成物粒子浓度上升,雷暴云电荷量和闪电发生率增加明显。(3)气溶胶浓度在1000~3000 cm?3范围时,云水竞争限制了冰晶的增长,导致雷暴云上部主正电荷堆电荷量降低。云滴和霰粒子浓度缓慢上升促进中部主负电荷堆和底部次正电荷堆电荷量继续增大。闪电发生率保持稳定。(4)当气溶胶浓度大于3000 cm?3时,水成物粒子浓度稳定,云内的电荷量以及闪电发生率保持为一定量级。
本文利用二維耦閤氣溶膠模塊的雷暴雲起電模式,結閤一次南京雷暴箇例,進行250 m分辨率雷暴雲起電模擬實驗,探討瞭氣溶膠濃度對雷暴雲空間電荷分佈以及閃電髮生率的影響。在這箇氣溶膠模塊中,假定一箇三模態的氣溶膠對數分佈,攷慮瞭氣溶膠活化過程。結果顯示:(1)隨著氣溶膠濃度增大,雷暴雲電荷結構保持為三極型。(2)噹氣溶膠濃度從50 cm?3增加至1000 cm?3時,水成物粒子濃度上升,雷暴雲電荷量和閃電髮生率增加明顯。(3)氣溶膠濃度在1000~3000 cm?3範圍時,雲水競爭限製瞭冰晶的增長,導緻雷暴雲上部主正電荷堆電荷量降低。雲滴和霰粒子濃度緩慢上升促進中部主負電荷堆和底部次正電荷堆電荷量繼續增大。閃電髮生率保持穩定。(4)噹氣溶膠濃度大于3000 cm?3時,水成物粒子濃度穩定,雲內的電荷量以及閃電髮生率保持為一定量級。
본문이용이유우합기용효모괴적뇌폭운기전모식,결합일차남경뇌폭개례,진행250 m분변솔뇌폭운기전모의실험,탐토료기용효농도대뇌폭운공간전하분포이급섬전발생솔적영향。재저개기용효모괴중,가정일개삼모태적기용효대수분포,고필료기용효활화과정。결과현시:(1)수착기용효농도증대,뇌폭운전하결구보지위삼겁형。(2)당기용효농도종50 cm?3증가지1000 cm?3시,수성물입자농도상승,뇌폭운전하량화섬전발생솔증가명현。(3)기용효농도재1000~3000 cm?3범위시,운수경쟁한제료빙정적증장,도치뇌폭운상부주정전하퇴전하량강저。운적화산입자농도완만상승촉진중부주부전하퇴화저부차정전하퇴전하량계속증대。섬전발생솔보지은정。(4)당기용효농도대우3000 cm?3시,수성물입자농도은정,운내적전하량이급섬전발생솔보지위일정량급。
AbstractA two-dimensional cumulus model coupled with an aerosol module is used to simulate a case of tropical convection in Nanjing. Numerical simulations at a resolution of 250 m are performed to investigate the effect of aerosol concentration on the electrification and lightning flash rate in the thunderstorm clouds. In this aerosol module, the distribution of aerosol particles is fitted by superimposing three log-normal distribution functions, and the activation of aerosol particles to form cloud droplets is considered. The results show that: (1) The charge structure in the thundercloud remains a triple charge structure as the aerosol concentration increases. (2) When the aerosol concentration is changed from 50 to 1000 cm?3, a stronger formation of cloud droplets, graupel and ice crystals results in an increasing charge separation and lightning flash rate. (3) In the range of 1000–3000 cm?3, the decrease in ice crystals caused by vapor competition leads to a reduction in upper positive charge, while the enhancement of graupel and cloud droplets results in the contribution of inductive charge to the middle negative charge region and lower positive charge region increasing with greater aerosol concentration. The flash rate shows a slight change. (4) At very high aerosol concentrations (above 3000 cm?3), the magnitude of the charge and lightning flash rate, which remains steady in the thundercloud, is insensitive to aerosol concentration.