The Green Flash – Westernmost Point of Latvia

The Green Flash and Green Ray are optical meteorological phenomena that sometimes briefly appear around sunset or sunrise. If the conditions are right, a distinct green spot briefly appears above the upper edge of the Sun's disc; the green appearance usually lasts no more than two seconds.

As explained by Ilgonis Vilks, a researcher at the Institute of Astronomy at the University of Latvia, and zoologist Vilnis Skuja, although the Green Ray can be seen even from a distance behind treetops, it is best viewed by the sea, where there is a flat horizon.

What exactly is the green line that encircles the sun sinking into the sea? "The Earth's atmosphere refracts sunlight, acting as a weak prism. Many people have participated in an experiment at school, which results in the colors of a rainbow. The upper edge of the Sun's disc appears like a rainbow strip.

Given that the Sun's disc is bright, we cannot see the rainbow until the very last moment," says Ilgonis Vilks.

It turns out that along the edge of the Sun's disc, there are also blue and violet colors. If you concentrate very hard, you can see a bit of them. "The atmosphere scatters the blue color the most, which is why the sky is blue." However, the green color breaks through.

This natural phenomenon is rare because, to see it, very clear air is needed, but usually, it is dusty and shimmering, says the astronomer. "A diligent sunset observer, who goes to the sea every evening, may see the Green Ray about five times during the summer. If the ray is only yellow-green, it is not noticed, because you have to know what you're looking for. The air and water temperature matter - the best effect is when the air is warm, and the water is cold, or vice versa.

Vilks adds that there is a belief: the Green Ray brings luck. He doesn't know where this belief comes from, but he is happy to believe in it.