The San Francisco Chronicle‘s David Perlman hasn’t any new science in this, just a literally colorful yarn about the established but somewhat arcane science behind a rare sight on a recent sunny day in the SF Bay Area. It seems that in the town of Concord a photographer looked into the azure above and saw an upside down rainbow. It wasn’t such; it was a circumzenithal arc. It lasted an hour or so. This is a nice example of turning the everyday into a page 1 science lesson and an enjoyable read too. It has to do, incidentally, with high-altitude ice crystals. It thus is related to other phenomena usually seen farther north such as sun dogs and holy lights.
The Tracker made a quick search to see other pics of circumzenithal arcs (try typing that fast a few times in a row!). The eye-popping clarity of this pic from the Concord witness, Andrew G. Saffas, stands out well above the others.
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