Korea Halos

Halos at Yanggu-gun, South Korea - Joon-Young Choi imaged them from the Center of Korea Observatory. ©Joon-Young Choi, shown with permission.

A classic display with 4 of the 5 ice crystal alignments contributing.

Random or poorly oriented crystals made the 22° halo and possibly a weak 46° halo.

The latter is uncertain because there is a strong overlapping supralateral arc from singly oriented column crystals. Columns also made the upper tangent arc topping the 22° halo.

Above that is a weak suncave Parry arc produced by the very improbably Parry oriented crystals. We only see Parry arcs because their generation is very efficient indeed. Otherwise the usual low concentration of Parry oriented crystals would only produce halos exceptionally rarely. The HaloSim ray tracing used a mere 1% Parry crystals.

Lowitz oriented crystals could be a less improbable but their arcs, unlike those of Parry, are produced very inefficiently with the result that we almost never see them.

Plate crystals are efficient halo makers and here they yielded the sundogs and most of the circumzenithal arc (Parry crystals also make CZAs).

All the crystal orientations contributed to the parhelic circle traversing the sun.