利用一个三维起电放电云分辨率模式,基于北京地区的一次探空数据,进行了孤立雷暴单体的模拟实验,并对模拟雷暴中上升运动较强阶段(最大上升速度Wmax >5 m·s-1),霰粒子发生非感应起电区域内的上升运动特点,及其与上升运动核心区(上升速度W >5 m·s-1)之间的空间关系进行了分析。结果表明,非感应起电区主要分布在上升运动核心区及其临近区域。出现在上升运动核心区内的非感应起电活动的起电效率通常较高(|非感应起电效率En-charging|> 0.1 nC·m-3)。上升运动中心也能够发生非感应起电。即使是在雷暴最大上升速度达到峰值时,在上升速度中心的霰粒子仍能发生非感应起电。但过强的上升速度不利于非感应起电效率的进一步提高。在该模拟雷暴中,效率较高的非感应起电活动多集中发生在Wmax > 5 m·s-1的时段内,区域则主要分布在-4~28 m·s-1的垂直速度区间内。对于具有更高效率的非感应起电活动(|En-charging| > 0.5 nC·m-3),尽管Wmax越大,具有更高效率的非感应起电活动区范围就越大,起电效率中心也更靠近上升速度中心,但起电效率中心与上升速度中心并不重合。大部分具有更高效率的非感应起电活动都发生在W < 20 m·s-1的上升运动区内。此外,上升速度中心高度在闪电活动的多数时间里与反转温度高度基本一致,可以用来区分霰粒子非感应起电获得不同极性电荷的区域:在分析时段内(第12~23 min)的大部分时间里,霰粒子获得负电荷的区域都出现在该高度附近或以上高度中,而获得正电荷的区域则基本出现在该高度以下。
Using a 3-D charging-discharging cloud resolution model,an isolated thunderstorm was simulated based on the sounding data in Beijing for investigating the spatial relationship between the updraft core(where the updraft speed Wmax >5 m·s-1)and the Graupel Non-inductive Charging Region(GNCR)when the maximum updraft speed was greater than 5 m·s-1.The characteristics of updraft in GNCR were also analyzed.The results showed that the GNCR was mainly distributed within and around the updraft core.The non-inductive charging processes in the GNCR always had a Relatively High Charging Efficiency(RHCE)with the absolute value greater than 0.1 nC·m-3.Even when the updraft of the cell reached peak,graupel in the region of updraft center can still obtain charge through the non-inductive charging processes.But too strong updraft speed was disadvantageous for appearance of More Efficient Non-inductive Charging Efficiency(MENCE),which absolute value was greater than 0.5 nC·m-3.In this simulation case,the RHCE almost appeared only when the maximum updraft speed was higher than 5 m·s-1.The regions with RHCE were usually distributed in the regions with the updraft speed range from -4 m·s-1 to 28 m·s-1.Although the area with MENCE would extend wider and its position would be closer to the updraft center while the maximum updraft speed became stronger,the center of the area with MENCE never overlapped with the updraft center,and always appeared in the region with the updraft speed less than 20 m·s-1.Additionally,the height of updraft speed center was approximately coincident with the height of inverted temperature.It could be used to separate the regions where graupels obtained negative and positive charges respectively through the non-inductive charging processes in operation in the future:during most of the time the updraft core existing,graupel in the regions near or above this height will obtain negative charge dominantly, graupel in the regions beneath this height will be charged by positive charge.
[1]Baker M B,Blyth A M,Christian H J,et al.1999.Relationships between lightning activity and various thundercloud parameters:satellite and modeling studies[J].J Atmos Res,51(3):221-236.
[2]Barthe C,Barth M C.2008.Evaluation of a new lightning-produced Nox parameterization for cloud resolving models and its associated uncertainties[J].Atmos Chem Phys,8(16):4691-4710.
[3]Barthe C,Deierling W,Barth M C.2010.Estimation of total lightning from various storm parameters:A cloud-resolving model study[J].J Geophys Res,115(D24):D24202.DOI:10.1029/2010JD014405.
[4]Carey L D,Rutledge S A.1996.A mlutiparameter radar case study of the microphysical and kinematic evolution of a lightning producing storm[J].Meteorol Atmos Phys,59(1-2):33-64.
[5]Deierling W,Petersen W A.2008.Total lightning activity as an indicator of updraft characteristics[J].J Geophys Res,113(D16):D16210.DOI:10.1029/2007JD009598.
[6]Gardiner B,Lamb D,Pitter R L,et al.1985.Measurements of initial potential gradient and particle charges in a Montana summer thunderstorm[J].J Geophys Res,90(D4):6079-6086.
[7]Hallett J,Saunders C P R.1979.Charge separation associated with secondary ice crystal production[J].J Atmos Sci,36(11):2230-2235.
[8]Kasemir H W.1960.A contribution to the electrostatic theory of a lightning discharge[J].J Geophys Res,65(2):1873-1878.
[9]Kasemir H W.1984.Theoretical and experimental determination of field,charge and current on an aircraft hit by natural and triggered lightning[C]//Orlando:International Aerospace and Ground Conference on Lightning and Static Electricity,National Interagency Coordination Group.
[10]Kuhlman K M,Ziegler C L,Mansell E R,et al.2006.Numerically simulated electrification and lightning of the 29 June 2000 supercell storm[J].Mon Wea Rev,134(10):2734-2757.
[11]Mansell E R,MacGorman D R,Ziegler C L,et al.2002.Simulated three dimensional branched lightning in a numerical thunderstorm model[J].J Geophy Res,107(D9):D94075.DOI:10.1029/2000JD000244.
[12]Mansell E R.2000.Electrification and lightning in simulated supercell and non-supercell thunderstorms[D].Norman,Oklahoma,USA:University of Oklahoma,1-211.
[13]Marshall T C,McCarthy M P,Rust W D.1995.Electric field magnitudes and lightning initiation in thunderstorms[J].J Geophys Res,100(D4):7097-7103.
[14]Pickering K E,Wang Y,Tao W K,et al.1998.Vertical distribution of lightning Nox for use in regional and global chemical transport models[J].J Geophys Res,103(D23):31203-31216.
[15]Soula S,Georgis J F.2013.Surface electrostatic field below weak precipitation and stratiform regions of mid-latitude storms[J].J Atmos Res,132:264-267.
[16]Tessendorf S A,Miller L J,Wiens K C,et al.2005.The 29 June 2000 supercell observed during STEPS.Part I:Kinematics and microphysics[J].J Atmos Sci,62(12):4127-4150.
[17]Wiens K C,Rutledge S A,Tessendorf S A.2005.The 29 June 2000 supercell observed during STEPS.Part II:lightning and charge structure[J].J Atmos Sci,62 (12):4157-4177.
[18]Ziegler C L,Macgorman D R,Dye J E,et al.1991.A model evaluation of non-inductive graupel-ice charging in the early electrification of a mountain thunderstorm[J].J Geophys Res,96(D7):12833-12855.
[19]胡志晋,何观芳.1987.积雨云微物理过程的数值模拟(一)微物理模式[J].气象学报,45(4):467-483.Hu Zhijin,He Guanfang.1987.Numerical simulation of microphysical processes in cumulonimbus.Part I:Microphysical model[J].Acta Meteor Sinica,45(4):467-483.
[20]孙晶,杨文霞,周毓荃.2015.河北一次降水层状云系结构和增雨条件的模拟研究[J].高原气象,34(6):1699-1710,Sun Jing,Yang Wenxia,Zhou Yuquan.2015.Numerical simulations of cloud structure and seedability of a precipitating stratiform in Hebei[J].Plateau Meteor,34(6):1699-1710.DOI:10.7522/j.issn.1000-0534.2014.00086.
[21]谭涌波.2006.闪电放电与雷暴云电荷、电位分布相互关系的数值模拟[D].合肥:中国科学技术大学,1-173.Tan Yongbo.2006.Numerical simulation of the relationship of the lightning discharge with the space charge and potential distribution in thundercloud[D].Hefei:University of Science and Technology of China,1-173.
[22]王晨曦.2014.雷暴中垂直气流特征与闪电活动关系研究[D].北京:中国气象科学研究院,1-66.Wang Chenxi.2014.The relationship between vertical airflow characteristics and lightning activity of thunderstorm[D].Beijing:Chinese Academy of Meteorological Sciences,1-66.
[23]吴学珂,袁铁,刘冬霞,等.2013.山东半岛一次强飑线过程地闪与雷达回波关系的研究.高原气象[J],32(2):530-540.Wu Xueke,Yuan Tie,Liu Dongxia,et al.2013.Study of the relationship between cloud-to-ground lightning and radar echo of a severe squall line in Shandong Peninsula[J].Plateau Meteor,32(2):530-540.DOI:10.7522/j.issn.1000-0534.2012.00050.
[24]言穆弘,刘欣生,安学敏,等.1996.雷暴非感应起电机制的模拟研究:Ⅰ.云内因子影响[J].高原气象,15(4):425-437.Yan Muhong,Liu Xinsheng,An Xuemin,et al.1996.A simulation study of non-inductive charging mechanism in thunderstorm I:Affect of cloud factor[J].Plateau Meteor,15(4):425-437.
[25]尹丽云,张杰,张腾飞,等.2012.低纬高原一次飑线过程的地闪演变特征分析[J].高原气象,31(4):1100-1109.Yin Liyun,Zhang Jie,Zhang Tengfei,et al.2012.Analysis on lightning activity characteristic of a squall line system in low-latitude plateau[J].Plateau Meteor,31(4):1100-1109.
[26]周志敏,郭学良,崔春光,等.2012.强风暴个例电荷结构及云闪放电差异的数值模拟[J].高原气象,31(3):810-824.Zhou Zhimin,Guo Xueliang,Cui Chunguang,et al.2012.Numerical simulation of difference of electric structure and discharge of cloud flash for two severe thunderstorm cases[J].Plateau Meteor,31(3):810-824.
