成雪

天上甘露凝成雪，山中泉水聚成冰冰雪严寒只等闲

Born of cold and winter air And mountain rain combining .

天上甘露凝成雪，山中泉水聚成冰

Born of cold and Winter air And mountain rain combining ,

雨要转成雪了吗？

Is the rain going to change to snow ?

君不见，高堂明镜悲白发，朝如青丝暮成雪。

See how lovely locks in bright mirrors in high Though silken-black at morning , have changed by night to snow .

垂直上升运动的加强和持续是水汽凝结和冻结成雪的必要条件；

The intension and persistence of vertical ascending motion was a necessary condition of vapor condensation and snow formed by freezing .

实施者通常有必要对层次结构加以精炼，并且随着需求的变化和成雪进行适当的调整。

It is usually necessary for the implementers to refine the hierarchical structures and make adjustments as the requirements grow and mature .

模拟的运动场和云微物理量场的时空演变表明，垂直运动场与水汽场的耦合是水汽凝结和冻结成雪的运动学条件；

The temporal and spatial evolution of simulated velocity and cloud microphysics fields show that the coupling of vertical velocity and vapor distribution is a criteria for vapor condensation and freezing that results in snow .

见了这种成团的雪落下来，就会说天上有成千上万的白蝴蝶。

One would say , to see all these snow-flakes fall , that there was a plague of white butterflies in heaven .

很多人会把雪花想像成从天而降的雪，因此他们会假设雪花会和雪球差不多大小。

Many people think that snowflakes are of snow faller from the sky and so they think that snowflakes are as large as a snowball .

对云中各种水成物的源、汇项分析表明，零度层下方雨水主要由高层落下的雪晶和霰融化而成，霰和雪则主要由其在冷区与过冷云雨水碰冻长大。

Rain water at the lower level is mainly generated from the melting of snow and graupel falling from the upper level where snow and graupel are generated and grown from collection with cloud and rain water .