180101期:瑞典上空的日晕

瑞典上空的日晕

 

太阳发生了什么事?有时候,我们好像是通过一个巨大的透镜看太阳。而在这部主题影片中,事实上我们是透过数百万个微小的冰晶透镜在看太阳。水可能会在大气中冻结成小的、扁平的六边形冰晶。这些冰晶飘落在地面上时,大部分时间扁平一面会与地面平行。在日出或日落时,观察者可能会发现自己和许多落下的冰晶在同一视线平面上。在这个过程中,每一个晶体都能像微型透镜一样,将阳光折射到我们的视野中,并出现“幻日”(幻日俗称sundog,学名为parhelia)的现象。这段视频是一个月前在瑞典斯德哥尔摩附近的Vemdalen滑雪度假村的一座雪丘的一侧拍摄的。在中心可以看到的是太阳最直接的样子,而两个明亮突出的幻日在左边和右边发着光。此外,在影片中可以看到的是张角为22度的日晕——以及更罕见、更微弱的由大气中的冰晶反射而产生的46度日晕

:银河说翻译组 岑

Sun Halo over Sweden
Video Credit & Copyright: Håkan Hammar (Vemdalen Ski Resort, SkiStar)

Explanation: What’s happened to the Sun? Sometimes it looks like the Sun is being viewed through a giant lens. In the featured video, however, there are actually millions of tiny lenses: ice crystals. Water may freeze in the atmosphere into small, flat, six-sided, ice crystals. As these crystals flutter to the ground, much time is spent with their faces flat and parallel to the ground. An observer may find themselves in the same plane as many of the falling ice crystals near sunrise or sunset. During this alignment, each crystal can act like a miniature lens, refracting sunlight into our view and creating phenomena like parhelia, the technical term for sundogs. The featured video was taken a month ago on the side of a ski hill at the Vemdalen Ski Resort near Stockholm, Sweden. Visible in the center is the most direct image of the Sun, while two bright sundogs glow prominently from both the left and the right. Also visible is the bright 22 degree halo — as well as the rarer and much fainter 46 degree halo — also created by sunlight reflecting off of atmospheric ice crystals.

发表评论

电子邮件地址不会被公开。 必填项已用*标注