7.3: Thermal Inversion

Question 1

Why do urban areas have higher surface and air temps compared to suburban and rural areas?

Answer 1

• Lower albedo due to concrete and asphalt absorbing most of the sun’s energy compared to areas with more vegetation
• Less evapotranspiration: water doesn’t evaporate as much; more of a tendency to run off so the transpiration from plants isn’t carrying heat from the surface into the atmosphere

Question 2

Thermal Inversion

Answer 2

Normally, warm air rises and carries pollutants away from the Earth’s surface and into the atmosphere. During a thermal inversion, a cooler air mass becomes trapped near the Earth’s surface
* Due to a warm front moving in over it
* Or due to hot urban surfaces cooling overnight while infrared radiation absorbed during the day is still being released

Question 3

Thermal Inversion and Pollution

Answer 3

Because cold air at the surface is trapped beneath the warmer mass above, convection doesn’t carry pollutants up and away leaving the smog, PM, ozone, SO2, NOx trapped closer to worth leading to resp irritation, decresaed tourism revenue, decreased photosynthesis rate.