瑞典的日晕
(原标题: Sun Halo over Sweden)
2021-12-28
浏览次数: 1
太阳怎么了？有时它看起来就像通过一个巨大的透镜观察太阳。然而，在这段精选视频中，实际上有数百万个微小的透镜：冰晶。水可能在大气中冻结成小而扁平的六面冰晶。当这些晶体扑向地面时，大部分时间它们的表面都是平的，与地面平行。在日出或日落时，观察者可能会发现自己与许多落下的冰晶处于同一平面。在这种排列过程中，每个晶体都可以像一个微型透镜一样，将阳光折射到我们的视野中，并产生类似幻日的现象，这是太阳的专业术语。这段视频拍摄于2017年底，地点是瑞典中部文达伦滑雪场的一座滑雪山坡。在中间可以看到的是太阳最直接的图像，而两个明亮的太阳从左边和右边突出地发光。同样可见的是明亮的22度光晕——以及更罕见、更暗淡的46度光晕——也是由阳光通过大气冰晶折射产生的。
查看原文解释
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 in late 2017 on the side of a ski hill at the Vemdalen Ski Resort in central 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 refracting through atmospheric ice crystals.
© Håkan Hammar (Vemdalen Ski Resort, SkiStar)