This yamato-e folding screen of chapter 20, "Asagao", was painted by Nansei Sakagami, who was born in 1947. Website. Although the chapter is named after the morning glory or bluebell, it's always the giant snowball that gets pictured.
On the way to the earth snow flakes get covered with hoar frost and interlock or freeze together into large snow flakes (up to 1 - 8 cm) ... in order to cover 1 square meter with snow cover to a depth of 1 meter, from several to tens of billions of snow flakes are needed ... they lie uncompacted on each other ... air is preserved between their plates, rays, and needles ... snow cover (according to Chirvinski 1932) resembles an emulsion of air and snow flakes, or a froth ... by this peculiarity the white colour of snow and its low temperature transmission can be explained ... the larger the snow flakes are, the less compactly they lie together ... in connection with this it should be noted that the specific gravity also changes ... by lying a long time or by slow melting, snow gets more compacted and can be turned into ice ... because of these pecularities, snow cover plays a very important role in preserving soil and plants from freezing ... its low thermal conductivity turns out to be very important in the ecology of animals.
Accumulated snow cover metamorphoses under the influence of a number of factors ... compaction of the snow and secondary recrystallization occur under the influence of gravity (this occurs especially in the lower layers), by partial melting and refreezing, which results in the appearance of compacted crusts and layers, and, in particular, under the action of wind which moves fine, dry snow from certain places and deposits it in others (ravines, forest borders, hedgerows), in the form of banks, hillocks, dunes, etc. ... drifting snow moves in the form of fine snow dust, which later forms especially compact layers under strong pressure from the wind ... cold rain and sublimation which form icy crusts, also take some part in the metamorphosis of snow ... particles transported by wind ('snowy detritus') are able to furrow and carve the surface of snow layers and even to inflict heavy damage to the barks of trees and bushes at the border of the tundra (Gorodkov 1926).
From A.N. Formozov, "Snow Cover as an Integral Factor of the Environment and its Importance in the Ecology of Mammals and Birds".