雪的不同种类 / Different Kind of Snow

作为一个从小没看过雪的南方少年，冬天的大雪一直是一件很新鲜的事情，来到中部之后才发现冬天的雪不仅很大。更惊讶的是我发现原来雪也是不一样的！就像白糖分为绵白糖和砂糖，雪的种类大致上也可以这么划分：一种是以大片雪花落下的绵雪，另一种是以大小不等的颗粒状落下的砂雪。砂雪和造雪机喷出的人造雪比较接近。没有认真研究过，为什么会形成绵雪或砂雪，也许和空气湿度和温度有关系吧！如果空气比较干燥，而温度又低的话，下砂雪的时候就比较多。
砂雪抓在手里很不爽，感觉冰冷，用力挤压，松开手仍然会散开，很难捏成团。而绵雪则不同，抓一把攥在手里，也许是其间缝隙更大的缘故，感觉不是特别的冰手，稍用力一攥，就形成了一个手雷状的雪团。无论滑雪，还是滚雪球、打雪仗，首选都是绵雪.

I had few chances to enjoy snowing when I was young. After moving to central west, snow becomes a common case now. More surprising thing is that I found there are different kind of snow. Atmospheric conditions affect how snow crystals form and what happens to them as they fall to the ground. Snow may fall as symmetrical, six-sided snowflakes, or it may fall as larger clumps of flakes. Similarly, once snow is on the ground, the snowpack may assume different qualities depending on local temperature changes, whether winds blow the snow around, or how long the snow has been on the ground. For instance, a fresh snowfall may be loose and powdery, but snow that has been on the ground throughout the winter may have dense, crusted layers caused by melting and refreezing. Scientists and meteorologists have classified types of snowfall, snowpack, and snow formations.