A host of angels sound their trumpets skyward over Kittilä, Finland. Images captured by Sauli Koski.    Images ©Sauli Koski
Below: Another way of visualizing them. Crystals along the dotted curve between the lamp and eye deflect light by 22 degrees into the eye. This is the bottom edge of the divergent light tangent arc.

To make them the angels first made ice crystals.

The glowing forms are ice halos. But halos with a difference. The crystals are at low level and glint light from nearby lamps on the ground to form 'divergent light halos'.

The flared trumpets are the divergent light halo variant of the more familiar upper tangent arc seen above the sun. Horizontal column crystals between the lamp and camera and along the complex surface at right glint light to make the halo.

More about them here.