The green flash at sunset's end is an elusive phenomenon.that sometimes appears when the last sliver of sun seems to be peeling away from the horizon line. The Earth's atmosphere act both like a prism and a lens.
On a clear day as the sun is setting into the ocean horizon (this in itself is rare because the sun tends to set behind the thick ever present ocean marine layer over the horizon), I managed to take 3 successive shots, the last showing the green flash. The wind was blowing hard, these are handheld shots, and I keep losing my subject within the frame for a few seconds, otherwise I would have had a larger image of the green flash at the end. Still I'm glad I caught a little sliver of the rare phenomenon.

Nikon P1000

crop, labels in Photoshop, collage in MS Paint