Abstract
The release of toxic gases into the atmosphere may reach concentrations that can cause undesirable
health, economic, or aesthetic effects. It is therefore important to monitor the amounts of
pollutants injected into the atmosphere from various sources. Most countries have a ground
network with multiple measuring sites and instruments, that can measure the air quality index
(AQI). However, the main challenge with the networks is the low spatial coverage. In this work,
satellite data is used to calculate for the first time the spatial distribution of AQI and pollutant
concentration over South Africa. The TROPOspheric Monitoring Instrument (TROPOMI) onboard
Sentinel-5P data is used to calculate AQI from carbon monoxide (CO), nitrogen dioxide (NO2),
ozone (O3), and sulfur dioxide (SO2) gases. The results that the month of June has the worst air
quality distribution throughout the country, while March has the best air quality distribution.
Overall, the results clearly show that TROPOMI has the capability to measure air quality at a country
and city level.
Implications: In this work, satellite data is used to calculate for the first time the spatial distribution
of the air quality index (AQI) and pollutant concentration over South Africa. The TROPOspheric
Monitoring Instrument (TROPOMI) onboard Sentinel-5P data is used to calculate AQI from carbon
monoxide (CO), nitrogen dioxide (NO2), ozone (O3), and sulfur dioxide (SO2) gases. Currently, South
Africa has a ground network of instruments that measure AQ, however, the network does not cover
the whole country. In this work, we show that the use of TROPOMI can compliment the current
network and provide data for the areas not covered.