CAJ | 학술논문

在三维强风暴动力-电耦合数值模式中分别引入两种基于不同实验室结果的非感应起电参数化方案S91和SP98,对比分析了一次雷暴单体首次放电前,利用两种方案模拟得到的非感应电荷转移区域、极性、量级和电荷结构的演变特征,及其与有效液态水、温度、粒子分布和对流之间的关系.结果表明,S91中,起电区域逐渐由高温、高有效液水区向低温、低有效液水区转移.电荷转移量快速增加,且由以正极性为主过渡为以负极性为主.电荷结构由偶极性转变到三极性.SP98中,淞附增长率的大值区范围较大,霰以携带正电荷占绝对优势,易形成反极性的电荷结构,但有进一步转变为三极性的趋势.两种方案的共同点表现为:电荷层较高,位于对流区上部及雷暴移动方向前侧出流区;正电荷转移多发生在高有效液态水(或淞附增长率)和高温区,负电荷转移都发生在低有效液态水(或淞附增长率)和低温区;转移电荷的正中心均位于霰的累积区中心,负中心易出现在冰晶和霰共存区的中心.
재삼유강풍폭동력-전우합수치모식중분별인입량충기우불동실험실결과적비감응기전삼수화방안S91화SP98,대비분석료일차뇌폭단체수차방전전,이용량충방안모의득도적비감응전하전이구역、겁성、량급화전하결구적연변특정,급기여유효액태수、온도、입자분포화대류지간적관계.결과표명,S91중,기전구역축점유고온、고유효액수구향저온、저유효액수구전이.전하전이량쾌속증가,차유이정겁성위주과도위이부겁성위주.전하결구유우겁성전변도삼겁성.SP98중,송부증장솔적대치구범위교대,산이휴대정전하점절대우세,역형성반겁성적전하결구,단유진일보전변위삼겁성적추세.량충방안적공동점표현위:전하층교고,위우대류구상부급뇌폭이동방향전측출류구;정전하전이다발생재고유효액태수(혹송부증장솔)화고온구,부전하전이도발생재저유효액태수(혹송부증장솔)화저온구;전이전하적정중심균위우산적루적구중심,부중심역출현재빙정화산공존구적중심.
A three-dimensional dynamic-electrification coupled model is used to investigate noninductive electrifica-tion before the first discharge in a single cell of thunderstorm.Two laboratory-based parameterizations of noninduc-tive graupel-ice charge separation,S91 and SP98,are compared.The evolution characteristics of noninductive charge separation regions,polarity,magnitude,structure and their relationships with effective liquid water content,environment temperature,hydrometeor distribution,and convection are analyzed in this paper.The model results suggest that,in S91 scheme,charge separation initially occurs in the region with high values of temperature and ef-fective liquid water content,and then moves to the region with low values.The charge separation rate quickly in-creases.Its domain polarity changes from positive to negative.The charge structure switchs from positive dipole to tripole.In SP98 scheme,graupel easily carries positive charges,owing to its large range of big rime accretion rate.It is likely to produce an inverted-polarity charge structure,but going with time,it tends to present tripole.There are some common characteristics between the two schemes before the first discharge.Firstly,the charge region alti-tudes are high and nearly located in the upper part of updraft and the outflow region in the front of storm moving di-rection.Secondly,positive charge separation primarily occurs in the region with high values of effective water con-tent(or rime accretion rate)and temperature,however,negative in the region with low values.Thirdly,the positive and negative charging centers are almost consistent during the evolution,respectively.The positive corresponds with the graupel number concentration center,while the negative easily occurs in the coexisting region center of ice and graupel.