The Growth of Ice Hydrometeors in Atmospheric Clouds

大冰粒在冰的物理学中起着核心作用， 云和降水，特别是在深对流云。 有两个过程对大型冰的形成很重要 颗粒，即结块和成霜过程。 的 成团过程产生雪聚集体，这些雪聚集体可以用作 雹、雹的胚。 然后是<$雨和冰雹 通过干燥和潮湿的生长阶段的凝结和循环来生长。 在凝结过程中，潜热会释放出来， 影响云的动态。 这些过程的影响 很大程度上取决于冰粒的生长速率。 不幸的是，我们之前对冰层生长的理解 过程主要是定性的。 主要困难在于 冰粒有复杂的形状， 复杂的流体动力学行为， 不稳定 在这笔资助下，王教授将使用云隧道 在洛杉矶加州大学进行 冰晶聚集实验，并进行 冰晶在空气中运动的理论计算。 教授 王先生有能力及完全有资格执行该项工作。

Large ice particles play a central role in the physics of clouds and precipitation, especially in deep convective clouds. Two processes are important for the formation of large ice particles, namely, the clumping and riming processes. The clumping processes produces snow aggregates which may serve as the embryos of graupel and hails. The graupel and hails then grow by riming and recycling through dry and wet growth stages. In the riming process, latent heat will be released which may influence the cloud dynamics. The impacts of these processes depend very much on the ice particle growth rates. Unfortunately, our previous understanding of the ice growth process is mostly qualitative. The main difficulty lies in the facts that ice particles have complicated shapes and thus complicated hudrodynamical behavior and that the motions are unsteady. Under this grant, Professor Wang will use the cloud tunnel at the University of California, Los Angles to conduct experiments of ice crystal aggregation, and also carry out theoretical computations of ice crystal motion in air. Professor Wang is competent and well qualified to carry out the work.