Anna Grove photographed these halos on September 8, 2013 in Cameroon, West Africa.
The innermost ice crystal halo is a weak circular 22° halo from randomly oriented hexagonal prisms.
Quite precisely aligned horizontal column crystals dominate the rest of the display. They made the intense circumscribed halo. Reflections from their hexagonal end faces generated the white parhelic circle crossing the sun. They also made the coloured arc near to the horizon – an infralateral arc.
A particularly unusual feature is the faint Wegener arc (horizontal columns again!) curving out across the sky from beneath the sun.
Another rarity is the high sun Parry arc, this from horizontal columns with two side faces also aligned horizontal.
Images ©Anna Grove, shown with permission