46度暈
46度暈是一種很罕見的出現在太陽附近的暈。當太陽與水平線的夾角呈15-27°時，46度暈很容易與上側弧與外側弧混淆。[1]
46度暈與22度暈相似，但更寬更淡。成因是陽光穿過六角形冰晶時，[2] 晶體之間90°的夾角使得其色彩分佈比22度暈更為分散。[3]
參考文獻
- ^ The 46° halo was first explained as being caused by refractions through ice crystals in 1679 by the French physicist Edmé Mariotte (1620–1684). See: Mariotte, Quatrieme Essay. De la Nature des Couleur (Paris, France: Estienne Michallet, 1681). Sun dogs as well as the 22° and 46° halos are explained in terms of refractions from ice crystals on pages 466 - 524 （頁面存檔備份，存於互聯網檔案館）.
- ^ 46°-halo. Arbeitskreis Meteore e.V. [2007-04-16]. （原始內容存檔於2007-03-31）.
- ^ Les Cowley (?). 46° Halo Formation. Atmospheric Optics. [2007-04-16]. （原始內容存檔於2019-01-19）. (including an illustration and an animation)
外部連結
- Atmospheric Optics - 46° Radius Halo（頁面存檔備份，存於互聯網檔案館） - including a HaloSim computer simulation and an Antarctica fish eye photo.