Vertical measurements of roadside air pollutants using a drone

In this study, we vertically measured concentrations of PM2.5, black carbon and ozone using a drone in a high-polluted area surrounded by highways, general road and high-rise apartments, from October 2021 to April 2022 in South Korea. We found that the concentration of PM2.5 and black carbon showed minor concentration changes vertically up to 70 m from the ground, and decreased with height over 70 m. This is due to the limited air circulation due to the 50-m-tall apartment buildings. The O-3 concentration was increased with height up to 30 m above the surface and increased slowly thereafter. This is due to the O-3 titration by NO near the surface to form NO2 and to turn O-3 into O-2. In addition, we analyzed the effect of wind direction on the pollutant concentration of the measurement site near a road where a sound barrier is located in-between. We found no appreciable increase in the pollutant concentration when wind is flowing from the nearby road. This may be attributable to the sound barrier that is blocking the direct pathway from the road and the measurement site.

Automated summary

In a highly polluted area in South Korea, concentrations of PM2.5, black carbon, and ozone were measured vertically using a drone. The results showed that air circulation was limited by the tall apartment buildings, leading to decreased concentrations of PM2.5 and black carbon above 70 meters and increased concentrations of ozone above 30 meters.