Göran Strand of Östersund, Sweden wrote:
The height of a rainbow depends on the height of the sun. When the sun is high in the sky we get a low rainbow and when the sun is low in the sky we get a higher rainbow.
In this picture taken by sunset, when the sun is at its lowest, the rainbow is the highest. With the reflection in the water you see that there is a perfect circle, this can only happen at sunset. If the sun was higher in the sky, we would have seen the rainbow and the reflection had the shape of an ellipse.
Outside the primary rainbow, it’s possible to suspect the secondary bow. It was a little more visible during shorter periods, but then the water wasn’t as cool.
Deborah Byrd created the EarthSky radio series in 1991 and founded EarthSky.org in 1994. Today, she serves as Editor-in-Chief of this website. She has won a galaxy of awards from the broadcasting and science communities, including having an asteroid named 3505 Byrd in her honor. A science communicator and educator since 1976, Byrd believes in science as a force for good in the world and a vital tool for the 21st century. "Being an EarthSky editor is like hosting a big global party for cool nature-lovers," she says.