An Investgation of the Air Bubble and Crystallographic Characteristics of Frozen, Soaked Rime

由于冰雹具有潜在的破坏性，因此冰雹形成的可能性是预报恶劣天气的重要组成部分。虽然气象学家对冰雹的生长特征有很好的了解，但决定某次雷暴是否会产生冰雹的因素还不是很清楚。冰雹呈圆形，表面有裂片或突起。横截面呈洋葱型层状结构，由于存在或多或少的气泡，不透明层和透明层交替存在。气泡和结晶学特征反映了冰雹形成的环境条件。冰雹结构和生长环境之间的一些关系已经被发现，还有更多的线索有待发现。在这笔资助下，Pflaum博士将研究在不同温度和压力下在实验室中生长的冷冻、浸泡的白霜的气泡和晶体学特性。在解码冰雹结构时，对这种关系的详细了解将有助于更好地解释生长环境。这些实验将在多伦多大学的云物理实验室进行。

Because of the destructive potential of hailstones, the likelihood of hail formation is an important component of forecasting severe weather. While meteorologists have a good knowledge of the growth characteristics of hailstones, the factors determining whether a particular thunderstorm will produce hail or not are not well understood. Hailstones are roundish in shape, with lobes or proturberances on the surface. The cross section exhibit an onion-type layered structure with alternating opaque and clear layers caused by the presence of more or less numerous air bubbles. The air bubble and crystallographic characteristics reflect the environmental conditions under which the hailstones are formed. Some relationships between hailstone structures and growth environments have been found, with additional clues to be uncovered. Under this grant, Dr. Pflaum will examine the air bubble and crystallographic properties of frozen, soaked rime grown in the laboratory with varied temperature and pressure. A detailed knowledge of the relationship will lead to a better interpretation of growth environments when decoding hailstone structures. The experiments will be conducted at the cloud physics laboratory at the University of Toronto.