For everything there is a season, and
a time for every matter under heaven:
a time to be born, and a time to die….
Ecclesiastes, chap. 3
To which a naturalist might add:
a time for rainbows, and a time for steam devils….
In the perceptive passage from Ecclesiastes, the teacher addresses episodic events in the lives of humans. Yet, the insight, that for everything there is a season, applies equally to the natural world. Normally, one does not look for rainbows in winter, nor for steam devils in summer. The study of quasiperiodicity in nature is phenology. While not as poetic as the teacher’s words, each speaks to nature’s seasonality.
What the devil?
Dust devils, snow devils, and steam devils are whirlwinds close to the surface. Why this name? Devil is from a Greek root meaning to throw. Satan earned it by throwing slander. Dust devils earned it by throwing dust.
With the arrival of cold, I knew the season was here for steam devils over the Lake. The devils playing on the water this year have not yet been quite as spectacular as ones I have seen during previous cold snaps, see steam devils, and devils’ playground. However, until it gets really cold again, these are the best I have.
To be able to see a steam devil, there has to be steam fog to serve as a tracer. With biting cold air flowing over the open waters of the Lake, convective sprites of steam fog abound. Occasionally, convection stretched a velocity gradient into a tall vortex and so created a steam devil. One appears in the foreground of this picture.
A very much taller but fainter steam devil appears in the distance. It probably would not have been noticed had it not been seen against the dark mountainside.