Abstract
Biomass burning (BB) in Southeast Asia is particularly pronounced during the dry season. However, the features of complex topography and long-range transport inherent to Southeast Asia have limited local research on pollution transport resulting from BB. In this study, monthly variation in aerosol optical properties in Southeast Asia six sites (Chiang Mai, Mukdahan, Bac-Lieu, Penang, Singapore, Bandungļ¼and fire-point distribution has been analysis detailed. The Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model was used to simulate the 72-hour back-trajectory of Shangri-La (Yunnan province, China) atmospheric background station. Our results showed that BB was more common on the Indochina Peninsula from March to May, whereas it was more common on the Malay Archipelago from August to October due to the latitude difference and crop harvest season. Serious BB activities at Indochina Peninsula in March resulted in a significant surge of aerosol extinction (AODt440nm = 1.32 ± 0.69, AODf440nm = 1.24 ± 0.59) with smaller diameter (AE=1.68 ± 0.13) in Chiang Mai. The long-range transport of BB aerosols reveal that the main substantial impact on Shangri-La’s pollution came from mid-northern India (accounting for 45.2%) and Bangladesh and northern Myanmar (accounting for 38.7%), which indicate the mainly aerosol pollution on the Yunnan–Guizhou Plateau in springtime could originate from the southern periphery of the Tibetan Plateau. The results also indicate that BB emission from Southeast Asia has a limited impact on pollution transportation in Southwest China, but a relatively large impact in local areas. This study is the first to analyze the trend of aerosols produced from BB in Southeast Asia on the basis of ground-based observed and it is helpful to have a deeper understanding of the potential effects of long-range transport of BB aerosols sources of outside to Southwest China.
