7.3: Thermal Inversion

How does the surface and air temperature of urban areas compare to that of rural areas?

The surface and air temperature in urban areas is higher

Why is there a higher surface and air temperature in urban areas?

Due to low albedo and less evapotranspiration

Why do urban areas have a low albedo?

Concrete and asphalt, which are common in urban areas, absorb heat form the sun

Why do urban areas have less evapotranspiration?

Urban areas have less vegetation, and as a result has less plants to perform transpiration, which could’ve carried heat away from the urban area.

How is the temperature like in the atmosphere normally?

It is warmest at the surface, and cools as you increase in altitude

What happens during thermal inversion?

The cooler air is trapped close to the surface due to the warmer air mass being above it

How does thermal inversion increase smog?

Due to the cooler air being trapped below the warm air mass, convection doesn’t allow for the pollutants to be taken away from the urban area, increasing smog.

Why does thermal inversion occur?

Either a warm front moving over it or due to urban areas cooling overnight while IR radiation absorbed during the day is being released

What happens normally to remove pollution from urban areas?

because warm air rises, air convection moves pollutants away from the urban area and up higher in the atmosphere

What are the effects of thermal inversion on humans?

Respiratory irritation, asthma flareups leading to hospitalization, worsened COPD, emphysema

What are the effects of thermal inversion on the environment?

decreased photosynthetic rate

What are the effects of thermal inversion on the economy?

decreased tourism revenue