Stupendous Swedish halos
A truly outstanding ice halo display observed by Magnus Edbäck at Borlänge Sweden.   Besides its sheer beauty, there are many rare and extremely rare halos. The enhanced and labelled image below shows them.     Image ©Magnus Edbäck, shown with permission
LEFT - A HaloSim computer ray tracing of the display. Note the sharp Lowitz arcs radiating from the parhelia and the 46 degree Lowitz below the circumzenithal arc. The latter are tangent to the 46 degree circular halo.

ABOVE - Rare arcs are labelled in red. The Hastings arc and 46 degree Lowitz arcs are rare indeed. There is a puzzlingly faint trace of an upper suncave parry arc and a subhelic arc is probably lurking somewhere.

Above each sundog and level with the upper tangent arc are bright patches. These are possibly a new halo produced by sun rays passing through two crystals rather than just one, a horizontal column and a plate crystal.

There is a ski centre 12 km from the location and its snow making machines were operating. The machines emit nuclei on which snow crystals form. Nuclei that get carried upwards give birth to slow growing and near optically perfect hexagonal column and plate crystals. They made these halos.


This fish-eye ray tracing shows the display's halos probably present away from the sun.

Whenever there is something exceptional in the sky always look in the opposite direction!