Shadow bands are “elusive ripples of alternate light and dark, flitting over the ground or the sides of buildings”
(to quote from the section on them in The Under-Standing of Eclipses).
Dr. Satyendra Bhandari, of Ahmedabad in India, wishes to organize an “International Shadow Band Campaign” during the approaching total eclipse. If you expect to be in or very near to the track of totality on August 21, he encourages you to write to him: space.scientist@gmail.com
He will no doubt send instructions on the simple observations needed, and some of his interesting thinking about shadow bands. He is working on a “Manual of Shadow Band Observations” and once shared a draft copy of it on SEML (the eclipse listserve), and is also preparing an introductory book on the subject. He regards shadow bands as one of the important effects of eclipse on Earth environment. The transition between daylight and darkness at sunset is “routine” and gentle, but the transition at the onset of total eclipse is a “shock” to the atmosphere, through which the Moon’s shadow is moving with supersonic speed.
Speaking of clear skies, I’ve been lucky viewing 2 previous Venus transits. A recent one in Chautauqua County NY, and one in the late 00’s driving toward the Silver Bridge in Gallipolis OH driving to Point Pleasant WV. The WV one was on a rising red-orange morning Sun, and you could look directly at it. I am fortunate I didn’t cause an accident driving over the Ohio River, but it was more interesting than seeing the Mothman.
The Silver Bridge in Callipolis – are you sure you didn’t make that up? A scene for an incident in a fantasy novel.
Elusive, indeed, is a word for shadow bands. During the 1991 eclipse in Baja, CA, just past totality, my German friend was telling me,to look at the sand; there they were; but I wasn’t seeing them. He insisted to keep looking and eventually they became apparent. I might liken them to the shadows of gasoline vapors on the ground you sometimes see while gassing up your vehicle in the sun. I found that spreading out a bedsheet on the ground makes them easier to observe. I haven’t seen them on vertical surfaces yet, but will certainly try next month.
Another feature I totally enjoy (yes, pun somewhat intended) are the crescent images appearing everywhere the sun manages to penetrate through any pinpoint of leaves of trees, holes in a colander, interstices of straw of straw hats, etc. It truly makes for some magical, mystical moments.
Hoping for clear skies for any and everyone who chooses to observe this most wondrous event.
I saw them in NY State during the May 10, 1994 Annular Eclipse on newly cut grass!