How nature gave Vancouver a perfect summer sunset (with lots of photos)

Last night, hundreds of people around Vancouver witnessed a spectacular sunset, and then quickly looked away from it and down to their phones.

Facebook, Twitter, Vine, and Instagram exploded in brilliant displays of atmospheric refraction.

The light show was widely declared the “nicest summer sunset of 2013”, and shared ad nauseam until it was replaced by darkness and the stars.

“Anytime there is a sunset, the colours arise because when the sun is low in the sky like that, its light is effectively travelling through a much thicker atmosphere,” said David Jones, a Vancouver-based meteorologist for Environment Canada.

He told the Straight that when the sun is high in the sky, the path through which light travels towards the Earth sees it pass through a thin section of the planet’s atmosphere. As a result, blue light rays are preferentially scattered and therefore most-visible.

“When the sun goes down, the path through the atmosphere is much longer, so all that blue light and the violets and all that end of the spectrum gets scattered out,” Jones continued, “and then you’re left with the reds and the oranges and the pink hues.”

But that happens every evening. What made July 16’s Vancouver sunset so special?

“You need clouds, for one thing,” Jones said. “And not just clouds but clouds at certain elevations.”

Clouds will give those shades of red and pink rays something to play off of, emphasizing light and creating more interesting displays.

But if the clouds are thick or too low, they’ll block out the sun’s setting rays, and eliminate the aesthetic effect. “14,000 feet or something like that, those clouds often create spectacular sunsets,” Jones said.

In addition, you want a bit of variety in your clouds.

“I saw some of those pictures and you could see it was very bright way off in the horizon, so that area was cloud-free,” Jones continued. “That light was travelling a long path towards your eye over Vancouver, and so the blues and violet colours were getting scattered out, and leaving all of those other red and violet colours, that were then reflected in the clouds above.

“The exact conditions for an ideal sunset,” he added.