A Laboratory Study of the Melt and Evaporation of Ice Precipitation

自然云中水物质的转化和分布对大气的热收支和运动能力都起着至关重要的作用。蒸汽、液体和冰之间的转换占对流层中部（15,000 - 20,000英尺）热量收支的20%左右，而水和冰的分布本质上决定了辐射场的关键成分。此外，云粒子的融化和蒸发会产生危险的向下运动，如下爆。本工作的目的是在动力学扩散室中模拟不同大气条件下冰粒子的融化和蒸发的实验研究；将检查颗粒破碎，清除和通电。结果将与最近在野外试验中获得的相关测量结果进行比较。约翰·哈雷特博士完全有资格从事这项工作；他被同行公认为最好的云物理学家之一。

The transformation and distribution of water substance in natural clouds play a crucial role in both the atmosphere's heat budget and its capacity for motion. The transformations between vapor liquid and ice account for about 20% of the heat budget in the mid-troposphere (15,000 - 20,000 feet), while the distribution of water and ice essentially defines a crucial ingredient of the radiation field. Further, melting and evaporation of cloud particles can produce hazardous downward motions such as downbursts. The objective of this work is the experimental examination of melting and evaporation of ice particles under various atmospheric conditions as simulated in a dynamical diffusion chamber; particle breakup, scavenging and electrification will be examined. The results will be compared with cognate measurements obtained in recent field experiments. Dr. John Hallett is well qualified to pursue this work; he is readily acknowledged by his peers to be one of the best cloud physicists.