Visibility, aerosol optical depth, and low-visibility events in Bangkok during the dry season and associated local weather and synoptic patterns.

Visibility and aerosol optical depth (AOD) characterization, and their relationship with PM and local and synoptic meteorology, were studied for January-March in 2014 and 2015 over Bangkok. Visibility degradation intensifies in the dry season as compared to the wet season due to increase in PM and unfavorable meteorological conditions. The average visibility is lower in January and February as compared to the other months.

Impact of transport of fine and ultrafine particles from open biomass burning on air quality during 2019 Bangkok haze episode.

Transboundary and domestic aerosol transport during 2018-2019 affecting Bangkok air quality has been investigated. Physicochemical characteristics of size-segregated ambient particles down to nano-particles collected during 2017 non-haze and 2018-2019 haze periods were analyzed. The average PM concentrations at KU and KMUTNB sites in Bangkok, Thailand during the haze periods were about 4 times higher than in non-haze periods.

The influence of the open burning of agricultural biomass and forest fires in Thailand on the carbonaceous components in size-fractionated particles.

Size-segregated ambient particles down to particles smaller than 0.1 μm (PM) were collected during the year 2014-2015 using cascade air samplers with a PM stage, at two cities in Thailand, Bangkok and Chiang Mai. Their characteristics and seasonal behavior were evaluated based on the thermal/optical reflectance (IMPROVE_TOR) method.