西弗吉尼亚州上空的火焰彩虹
(原标题: A Fire Rainbow over West Virginia)
2026-08-02
浏览次数: 1534
这片云发生了什么？远处卷云中的冰晶就像漂浮的小棱镜。由于其类似火焰的外观，人们非正式地称之为火彩虹，一个与地平线平行的环地平线弧。要想看到一个环水平的弧线，太阳必须在天空中至少58度高，而卷云在下面——在这种情况下是卷云。组成卷云的无数扁平六边形冰晶必须水平排列，才能以类似的方式适当地折射阳光。因此，环绕水平的弧线有些不寻常。这幅特色的火彩虹于2021年在美国西弗吉尼亚州的北福克山附近拍摄。《天空惊喜》：《APOD》在你生日那天给你拍了什么照片？(1995年以后)
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What's happening to this cloud? Ice crystals in a distant cirrus cloud are acting like little floating prisms. Known informally as a fire rainbow for its flame-like appearance, a circumhorizon arc appears parallel to the horizon. For a circumhorizontal arc to be visible, the Sun must be at least 58 degrees high in a sky where cirrus clouds present below -- in this case cirrus fibratus. The numerous, flat, hexagonal ice-crystals that compose the cirrus cloud must be aligned horizontally to properly refract sunlight in a collectively similar manner. Therefore, circumhorizontal arcs are somewhat unusual to see. The featured fire rainbow was photographed in 2021 near North Fork Mountain in West Virginia, USA. Sky Surprise: What picture did APOD feature on your birthday? (after 1995)
© Christa Harbig