Glossary
Air Pollutants
Harmful substances released into the atmosphere, which can become concentrated near the ground during a thermal inversion.
Example:
During an inversion, air pollutants like fine dust and vehicle emissions can build up to unhealthy levels.
Carbon Monoxide (CO)
A colorless, odorless, and highly toxic gas produced by the incomplete combustion of carbon-containing fuels, often from car exhaust.
Example:
Running a car in an enclosed garage can quickly lead to dangerous levels of carbon monoxide.
Heart Disease
A range of conditions that affect the heart, with long-term exposure to air pollution being a significant risk factor.
Example:
Studies have linked prolonged exposure to fine particulate matter to an increased risk of developing heart disease.
High Pressure Systems
Atmospheric conditions characterized by sinking air, which can warm as it descends and contribute to the formation of thermal inversions.
Example:
A persistent high pressure system over a region can lead to stagnant air and increased chances of an inversion event.
Nitrogen Oxides (NOx)
A group of highly reactive gases containing nitrogen and oxygen, primarily formed during high-temperature combustion in vehicles and power plants.
Example:
The reddish-brown haze often seen over cities is partly due to nitrogen oxides reacting in the atmosphere.
Normal Atmospheric Conditions
Typical atmospheric state where air temperature decreases with increasing altitude, allowing warm air and pollutants to rise and disperse.
Example:
On a clear, windy day, normal atmospheric conditions help carry away exhaust fumes from city traffic.
Particulate Matter (PM)
Tiny solid particles or liquid droplets suspended in the air, originating from sources like dust, smoke, and industrial emissions, which can be trapped by inversions.
Example:
Smoke from wildfires releases significant amounts of particulate matter, which can travel long distances and worsen air quality.
Respiratory Problems
Health issues affecting the lungs and breathing passages, often exacerbated by exposure to concentrated air pollutants during thermal inversions.
Example:
People with asthma often experience increased respiratory problems when air quality is poor due to trapped pollutants.
Smog
A type of air pollution forming a hazy mixture of smoke and fog, often intensified by thermal inversions trapping pollutants near the ground.
Example:
On a still, sunny day in a polluted city, the air can become thick with smog, reducing visibility.
Thermal Inversion
A meteorological phenomenon where a layer of warm air traps a layer of cooler air beneath it, preventing vertical air movement and pollutant dispersion.
Example:
During a thermal inversion in a valley, smoke from a campfire might linger close to the ground instead of rising and dissipating.
Topography
The arrangement of the natural and artificial physical features of an area, such as mountains and valleys, which can influence air movement.
Example:
The mountainous topography surrounding Los Angeles contributes to its frequent thermal inversions by trapping air.
Volatile Organic Compounds (VOCs)
Organic chemicals that have a high vapor pressure at room temperature, emitted from sources like paints, solvents, and vehicle exhaust, contributing to smog.
Example:
The distinct smell of new paint or gasoline is often due to the presence of volatile organic compounds.