The Science Corner With Jiansi Dun

I've noticed something odd lately. It's extremely cold in the mornings, due in no small part to the gentle but icy winds coming down from Russia. It stays cold throughout the day. And yet, when the sun goes down - a time when you'd think it would be even colder - the air feels warmer. Notably warmer, in fact. Strange, huh?

But as I pondered this, I realized that I knew exactly why this was. And it would give me a chance to sneak some science onto this site.

Truth is, it's warmer at night in many cities, due to a recognized scientific phenomenon known as the heat island effect. Here's the capsule version: Cities have more dark surfaces (roads, parking lots, rooftops, etc) than rural areas. Black surfaces absorb visible light (namely sunlight) during the day. Provided that the area is not windy (strong winds negate the effect), the energy from the sun is stored until nightfall, at which point it is released as heat. Thus, the energy from the sun keeps the city warm despite its absence. Nifty, huh?