Sunless winter doesn’t prevent warming in cities
M. Varentsov/Lomonosov Moscow State Univ.
TROMSØ, Norway — A novel form of the “urban heat island” effect might contribute to why the far north is warming faster than the rest of the globe, a study of five Arctic cities finds.
Sunlight can heat dense building materials. When night falls, buildings will release some of their solar energy into the air. This helps explain why urban centers tend to be a few degrees warmer than nearby rural areas.
“We decided that our Russian Arctic cities should also show this phenomenon,” says Mikhail Varentsov, a climatologist at Lomonosov Moscow State University. But indoor heating — not the sun — would be the major heat source, at least in winter, when the sun shines little if at all. To test that idea, he and colleagues set up weather stations to collect data in the five