Unit 7: (7.3) Thermal Inversion-(7.4) Natural Air Pollutants

Atmospheric Temperature Gradient

Normally, temperature decreases as altitude increases. This is because warm air rises, expands, and cools

thermal inversion

A situation in which a relatively warm layer of air at mid-altitude covers a layer of cold, dense air below. This prevents air near the surface from rising, trapping air pollutants near the surface

basin

a low place in the surface of the land, usually with mountains on either side. Worsens smog formation due to lack of airflow

Terpenes & Ethylene

Natural VOCs given off by coniferous (pine trees)

Volcanoes

natural source of carbon dioxide, sulfur dioxide, PM, carbon monoxide in the atmosphere

Lightening strikes

Natural source of NO2

Forest fires

Natural source of CO2, CO, PM, NO2

Decomposition of dead biomass

Natural source of CO2 & NO2