Air Pollution Lab
Explore how temperature inversions trap pollutants near the surface and how wind speed affects dispersion. Adjust inversion height, strength, and wind to observe real-time changes in AQI, then collect data across multiple trials.
Guided Experiment: Temperature Inversion Investigation
If you decrease the inversion height while keeping wind speed constant, what do you predict will happen to air quality (AQI)?
Write your hypothesis in the Lab Report panel, then click Next.
Air Quality Visualization
Controls
Results
AQI vs Inversion Height
Data Table
(0 rows)| # | Trial | Condition | Surface Temp(°C) | Inversion Ht(m) | Wind Speed(m/s) | AQI | Mixing Vol(m³/m) | PM2.5(μg/m³) |
|---|
Reference Guide
Temperature Inversions
Normally, air temperature decreases with altitude. A temperature inversion reverses this, creating a warm layer above cooler surface air. This warm lid prevents vertical mixing and traps pollutants below.
where Γ is the lapse rate (6.5 K/km), h is the inversion height, and ΔT is the inversion strength. Los Angeles experiences frequent subsidence inversions due to the Pacific high-pressure system.
Box Model
The atmospheric box model estimates pollutant concentration by treating the mixing layer as a well-mixed box. Concentration depends on the emission rate and the ventilation coefficient.
where E is the emission rate, H is the mixing height (m), and u is the wind speed (m/s). The ventilation coefficient V = H × u determines the atmosphere's capacity to dilute pollutants.
Air Quality Index
The EPA AQI converts pollutant concentrations into a 0-500 scale using piecewise linear breakpoint interpolation.
Ventilation Coefficient
The ventilation coefficient measures the atmosphere's ability to disperse pollutants. It combines the mixing height and transport wind speed.
Values below 6,000 m²/s indicate poor ventilation and high pollution potential. Weather services use this metric in air quality forecasts. Stagnation events (low wind + low mixing height) produce the worst air quality episodes.