Visibility IV / V
Here’s a summary of the more common halos of last Thursday morning’s surface halo party. The unknown white arcs that appeared at the same site and the spectrum flickering in the nadir are presented in observation 87312. During the warm period, the water and sludge melted on the ice had re-frozen and formed two types of crystal substrates.
Near the shore, there was fine snow on the older ice, the crystals that grew on the surface of which had a well-stretched low-lying lower sun and a 46 ° ring. Instead, the 22 ° ring was completely missing. I also found surface solar arcs in the pictures in the evening. The crystals associated with these halos appear at the top of the last image.
In the middle of the lake, the ice was shiny and seemed to consist of large mosaic tiles. The entire pieces of mosaic shone colorful, forming bright underside suns. I didn’t guess to go on the ice to take a closer look at the surfaces where the sub-side suns shone, but their crystal surfaces were possibly similar to the crystals I photographed from the float platform in a slightly smaller mosaic shown at the bottom of Figure 8. What is special about them is that, each mosaic surface always consisted of vertically grown crystals arranged in the + - direction, and on the adjacent surfaces their orientations and sizes varied randomly.
EDIT: New change, Figure 7 changed to simulation, related assumptions and observations in comments.