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| North American viewers should count their blessings for the halo is fairly common there although most often seen only as a fragment. Mid to northern Europeans see it far less often because the sun is lower. |
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| This summer only ice halo requires the sun to be higher than ~58°. Above that altitude, rays can enter the side faces of horizontal plate crystals and leave through the bottom hexagonal face. The refraction through what is essentially a 90 degree prism gives widely separated and pure spectral colours. Lower the sun and the rays cannot leave the lower face. Instead they internally reflect and eventually emerge to make a white parhelic circle, a sundog or some other halo. |
| Twin Sisters Range Circumhorizon Arc - John Scurlock ( Mountain Aerial Photography ) pictured the scene while he was flying near the Twin Sisters Range east of Bellingham, Washington. The camera looks to the south/southwest towards Puget Sound. John has captured the sheer immensity of the halo which can stretch 90° and more around the horizon. ©John Scurlock, shown with permission. |