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sun pillar
sun pillarn. A vertical streak of light sometimes appearing above or below the sun, especially at sunset or sunrise, caused by the reflection of sunlight by ice particles suspended in Earth's atmosphere.Sun Pillar
sun pillar[′sən ‚pil·ər] (meteorology) A luminous streak of light, white or slightly reddened, extending above and below the sun, most frequently observed near sunrise or sunset; it may extend to about 20° above the sun, and generally ends in a point. Also known as light pillar. Sun Pillar an optical phenomenon in the atmosphere. Sun pillars are streaks of white or, sometimes, slightly reddened light extending above and below the sun. They are observed primarily in winter when the weather is cold and are best seen at sunrise and sunset. Sun pillars occur when horizontally arranged flat hexagonal ice crystals (plates) are present in the atmosphere. The pillars are a result of the reflection of the sun’s rays from the bases of the crystals, which are slowly falling toward the earth’s surface. Light pillars are also sometimes seen above and below the moon. |