内蒙古出现“光柱”奇景-Light Pillars appeared in Inner Mongolia

12 月 30 日夜晚，内蒙古锡林浩特地区出现罕见的“日柱”奇景，场面十分壮观。这些画面被很多网友用手机和相机记录了下来，并迅速的在网上流传开来。

这种现象是由于天气很冷的时候，而太阳又刚好升起或者落下，此时当雪从高处落下时，会形成一个平面状态，形状就像是一些冰晶。而这些冰晶反射的阳光刚好处于垂直状态，因此就会形成日柱的奇景。
该现象从晚 21 时左右出现，一直持续到凌晨，当时室外气温为零下 20 摄氏度左右，晴朗无风，非常适合拍摄。

Light pillars are seen in Xilinhot City, in north China's Inner Mongolia Autonomous Region on Dec. 30, 2015. The effect is created by the reflection of light from numerous tiny ice crystals suspended in the atmosphere or clouds. The light can come from the Sun (usually when it is near or even below the horizon) and causes the phenomenon called a sun pillar or solar pillar. It can also come from the Moon or from terrestrial sources such as streetlights. 

• Light pillars, or sun pillars, form when sunlight - or another bright light source - bounces off the surfaces of falling ice crystals.
• The ice crystals are usually associated with thin, high-level clouds and are falling through the atmosphere when the phenomenon occurs.
• Light pillars are most often seen when the sun is low in the western sky before sunset, or low in the east just after the breaking of dawn.
• The moon or streetlights can also create this light phenomenon.

Source: Earthsky.org
Light pillar pictures at National Geographic