Wednesday, 12 April 2017

sun pillar and swallows


Here's a sun pillar, at dawn over the Kennet and Avon Canal at Sells Green in Wiltshire. It's caused by the sunlight being reflected by falling ice crystals. We were moored here for a week or so, and ticked off the waypoints of the spring as they passed us; the first willow warbler a few days ago; yesterday the first sedge warbler. And two swallows which flitted past, heading north. They are evidently making a summer somewhere else, because we've seen no more, yet.


While we're thinking of odd and beautiful things in the sky, here's a circumzenithal arc, or possibly a parahelion, caused by the light refracting through a horizontal layer of ice crystals. This was at Avoncliff on May Day last year.


...and here's a pair of sundogs, either side of the setting sun, near Lympley Stoke last winter. You can see the flooded Avon down there in the valley.