强对流(冰雹)云中水凝物的积累和云水的消耗

THE ACCUMULATION OF HYDROMETEOR AND DEPLETION OF CLOUD WATER IN STRONGLY CONVECTIVE CLOUD (HAILSTORM)

中文关键词:  水凝物积累  过冷水消耗  冰雹形成机制

英文关键词:Accumulation of hydrometeor  Depletion of super-cold water  Mechanism of hailstone formation

中文摘要:

      在冰雹云中过冷水的累积对冰雹增长起重要作用。文中回顾了水凝物累积和过冷水消耗机制中的不确定性,利用三维Euler强对流云模式和三维Lagrange粒子群运行增长模式,重新研究了对流云中水凝物粒子的累积机制和过冷水的消耗图像,得出以下结果:(1)强对流(冰雹)云具有翻滚式对流流场,流场的性质决定云中存在着一个动力吸引区,它处于主上升气流区旁侧水平气流近于零的区域,粒子在增长运行中向这里集中,造成水凝物的累积;(2)这种粒子的集中和水凝物的累积,是流场动力特征和粒子增长行为相互作用的表现;(3)粒子的集中和水凝物的累积是动态循环式的,而不是静态平衡式的,粒子可以进入吸引区,也可以吹离吸引区,在进入和吹离的循环中动态地形成了集中和累积,累积可以发生在主上升气流上方,也可以延伸到其下方;(4)粒子的集中和水凝物的累积是受流场和粒子运动的动力过程控制的,而累积粒子是液相雨滴,或是固相霰粒、雪团和冰雹是受降水发展过程属液相或固相占优势来决定的;(5)云水场中云水量,只在大粒子的集中区才被显著消耗;而在区外的云水量消耗不显著;(6)对于云水含量高达6g/kg的云水场,播撒粒子浓度达到100个/m³时,在考虑消耗时,已不能增长成直径大于1cm的冰雹。

英文摘要:

      It is well known that the accumulation of liquid hydrometeor is very important for large hailstone's formation, but there are some uncertainties for accumulating mechanism of hydrometeor particles. Therefore the mechanism of accumulation is re-simulated by use of 3D- Euler model for macro and micro cloud fields and 3D-Lagrange growth travel model for the behavior of hydrometeor particles, following results have obtained: (1) Due to the airflow field is convective there is a dynamically attractive region located by the main updraft and here the horizontal velocity of airflow is near by zero, the particles may come together here, and then the accumulation occurred. (2) The accumulation is controlled by the interaction between the airflow field and the behavior of particles growth-travel, the accumulation of particles without growth is impossible. (3) The accumulation or convergence of particles is cyclic and developmental, the particle may entry the accumulation region or run out in process of accumulation. (4) The accumulating process is controlled by airflow and particle's behavior, but the accumulation of particles is of liquid(rain drops) or solid (snow、graupel or hail) that is cont rolled by the cloud-precipitation micro-physics. (5) The depletion of cloud-water or rain-water occurred in accumulation region mainly. (6) When the content of cloud-water is 6.0 g/kg and the concentration of particles is over 100.0/m³ the final size of particle is below 1.0 cm during the growth-travel.