Yellowknife Halos Diamond dust halos at Yellowknife, Northwest Territories, Canada pictured by Tom Andrews on an iPhone5. ©Tom Andrews, shown with permission |
Further from the sun is a 46° halo. In diamond dust displays with very bright sundogs, always look for an extremely rare 44° parhelion inside the point where the 46° halo crosses the parhelic circle. The brightening near the parhelic circle in this view is probably produced by a greater concentration of diamond dust rather than extra parhelia. |
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Dominating the display is the huge 'V' shaped upper tangent arc that gets its name from just touching the 22° halo. Horizontal column crystals generate the tangent arc and also contribute to the parhelic circle passing through the low sun. There are weak sundogs but there were not so many plate crystals in this diamond dust. At right the 22° halo continues faintly below the horizon. This could be from grounded ice crystals or nearby airborne ones. |