Wildfires and biomass burning in northern Thailand: Observations from ASIA-AQ Campaign

Southeast Asia experiences widespread wildfires and biomass burning events during the dry season (January to April), leading to poor air quality, haze, and smog. NASA conducted the Airborne and Satellite Investigation of Asian Air Quality (ASIA-AQ) flight campaign in February and March 2024 to study the contribution of smoke to urban air quality through a multi-faceted observational approach (aircraft, satellite, and ground). The campaign deployed the NASA DC-8 aircraft, equipped with instruments from the Langley Aerosol Research Group (LARGE) and other teams, to measure real-time aerosol microphysical and optical properties, trace gases, and meteorological parameters. During the campaign in the Philippines, South Korea, Thailand, and Taiwan, it was noted that the northern region of Thailand was predominantly impacted by agricultural residue burning and wildfires. Here, we present the variations of vertical and horizontal profiles of aerosol properties and biomass burning tracers, alongside meteorological data to assess the impacts of local conditions and potential pollution pathways. Key findings will include observed variability in aerosols properties, the role of absorbing and scattering aerosols, boundary layer dynamics, and regional pollution transport across the ASIA-AQ domain.