Air Quality Data Analysis: AQI, PM2.5 Averages & Exceedances
Convert ppb to µg/m³, build valid 24-hour means from hourly data, calculate US AQI sub-indices by interpolation, count exceedance days against the WHO 2021 guidelines, chart the daily NO2 cycle, compare weekdays with weekends and build an emissions inventory: 8 graded labs on synthetic station data.
The first lesson is free — no account needed.
About this course
An air quality data analysis course that works through synthetic monitoring data of one fictional town in a spreadsheet, for environmental science students, health and planning staff and analysts. You convert gas readings between ppb and µg/m³ at 25 °C and 20 °C, turn hourly PM2.5 with gaps into 24-hour means with a 75% data-completeness rule, calculate US AQI sub-indices by truncating, finding the breakpoints with MATCH and interpolating, combine four pollutants into the daily AQI and its main pollutant, count exceedance days against the WHO 2021 24-hour guideline and the 99th percentile, chart the daily NO2 cycle by hour, compare weekdays with weekends and build an emissions inventory from activity data and emission factors. The breakpoints follow the US EPA AQI and the guideline values the WHO 2021 guidelines in general terms. Synthetic data, educational only. The first lab is free.
Lessons
- Units: ppb ↔ µg/m³ with Molar Mass & Reference TemperatureFree
- Hourly to 24-Hour Means & the 75 % Data-Completeness Rule Pro
- AQI Sub-index: Truncate, Find the Breakpoints & Interpolate Pro
- Overall AQI: Highest Sub-index, Main Pollutant & Category Pro
- Exceedance Days vs the WHO Guideline: COUNTIF, COUNTIFS & the 99th Percentile Pro
- Diurnal Pattern: Mean NO2 by Hour of Day (AVERAGEIFS & Chart) Pro
- Weekday vs Weekend: The Traffic Signature in NO2 Pro
- Emissions Inventory Basics: Activity × Emission Factor Pro