The Green Flash – At Last!
At last, I enjoyed a successful attempt to capture the elusive green flash.
During three weeks at sea attempts almost every evening from the ship to sight the green flash always failed, as the Sun set behind low horizon cloud.
But this night, the Sun set into the ocean with a clear horizon. My location was a small public oceanside walkway on Bay Street near Bridgetown, Barbados. It was a great spot to watch the sunset, though our main purpose for stopping there was to pick up some fried chicken at the KFC just steps away!
But the imminent sunset under ideal conditions made it worthwhile sticking around to see if we (I was with two friends from Alberta) could sight the green flash.
We did! I shot a rapid fire sequence – the image above is one frame of many catching the last bit of the Sun remaining above the horizon and turning green.
The infamous green flash is a refraction effect caused by the atmosphere separating out the green light and lifting it higher so it’s the last thing you see as the Sun sets. Conditions aren’t always amenable to seeing the green flash – you need a clear horizon and you also need the atmosphere structured with warm layers near the sea creating a mirage effect.
For more details on the technical explanations see Andrew Young’s page at http://aty.sdsu.edu/
… and Les Cowley’s page at http://www.atoptics.co.uk/atoptics/gf1.htm
Andrew Young has a nice simulation at http://aty.sdsu.edu/explain/simulations/inf-mir/inf-mirSS4GF.html
This was the view moments before, with the lower edge of the setting Sun distorted by atmospheric refraction, a sign that you might see a green flash as the upper edge disappears.
I shot this image a few minutes earlier as a photogenic sailboat drifted into the scene. Red sails in the sunset!
I’m nearing the end of my stay in Barbados and my 4 weeks away from home. There are heavy snowfall warnings out for southern Alberta this weekend so I’m not anxious to return! But winter will be waiting for me next week.
– Alan, November 16, 2013 / © 2013 Alan Dyer