How does the pavement and buildings in a city affect local climate?
1 Answer
It creates what we call a "heat island".
Explanation:
Pavement has a lower albedo than just about any plant life. This means it absorbs sunlight more readily than just about anything else. As a result it gets warmer. This coupled with heat generate by other human activity creates what is know as a "heat island", or an area that is simply hotter than the surrounding areas. As pavement releases this built up heat slowly, we see a greater effect at night than in the day. Also, due to the fact that snow cover greater increases albedo, the effects are much more pronounced in the summer.
The way this effects weather is very interesting. At work I watch thunderstorms on the radar moving toward cities all the time in the summer an then I watch them get deflected around the city. Where I am we have a highway surrounding the city that is called the Perimeter Highway (original no?). At the weather office we unofficially refer to the effect of the city heat island as the "Perimeter highway effect".
