Wildfire Effects on Air Quality: A Case Study of Wildfires in Korea in 2022

In March 2022, an unprecedented largest forest fire occurred in South Korea, burning 22,477 ha of forest for two weeks. In this study, we studied the causes of these fires based on an analysis of all meteorological data available over 100 years and also investigated their effects on air quality data obtained from ground-based observations (AirKorea and Asian Initiative for Clean Air Networks (AICAN)) and satellite data. Analysis results of meteorological data reveal changes in the climate regime from cold and wet winter conditions to hot and dry conditions. The temperature has been increased by 4 °C and precipitation has decreased by 17 mm over 100 years. The resistance level of forest fires is drastically reduced in the past few years and eventually lead to large-scale wildfires. These devastating wildfires emitted large amounts of ultrafine biomass-burning aerosols that were composed mainly of small particle sizes with diameters less than 1.0 mm. It elevated the air pollution level by more than 20 folds than usual condition. Carbon monoxide (CO) was also emitted from biomass burning that was detected as smoke paths (from 373 ppb to 1181 ppb) by the Tropospheric Monitoring Instrument (TROPOMI). This study highlights that climate change can make forests more vulnerable to fires and their effects on air quality could be more severe than expected.

This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (No. RS-2022-00155875).