In this study, size-fractionated particulate matters (PM) down to ultrafine (PM_0.1) particles were collected using a cascade air sampler with a PM_0.1 stage, in Hat Yai city, Songkhla province, southern Thailand during the year 2018. The particle-bound carbonaceous aerosols (CA) as elemental carbon (EC) and organic carbon (OC) were quantified with the thermal/optical reflectance method following the IMPROVE_TOR protocol. The concentrations of different temperature carbon fractions (OC1-OC4, EC1-EC3 and PyO) in the size-fractionated PM were evaluated to discern OC and EC correlations as well as those between char-EC and soot-EC. The results showed that biomass burning, motor vehicle, and secondary organic aerosols (SOC) all contributed to the size-fractionated PM. The OC/EC ratios ranged from 2.90 to 4.30 over the year, with the ratios of PM_2.5-10 being the highest, except during the open biomass burning period. The concentration of CA was found to increase during the pre-monsoon season and had its peak value in the PM_0.5-1.0 fraction. The long-range transport of PMs from Indonesia, southwest of Thailand toward southern Thailand became more obvious during the pre-monsoon season. Transported plumes from biomass burning in Indonesia may increase the concentration of OC and EC both in the fine (PM_0.5-1.0 and PM_1.0-2.5) and coarse (PM_2.5-10 and PM_>10) fractions. The OC fraction in PM_0.1 was also shown to be significantly affected by the transported plumes during the pre-monsoon season. Good OC and EC correlations (R² = 0.824–0.915) in the fine particle fractions indicated that they had common sources such as fossil fuel combustion. However, the lower and moderate correlations (R² = 0.093–0.678) among the coarser particles suggesting that they have a more complex pattern of emission sources during the dry and monsoon seasons. This indicates the importance of focusing emission control strategies on different PM particle sizes in southern Thailand.

在这项研究中，使用具有PM _0.1的级联空气采样器收集了分离成超细颗粒（PM _0.1）的颗粒大小的颗粒物（PM）。阶段，于2018年期间在泰国南部宋卡府的合艾市进行。通过IMPROVE_TOR的热/光反射法对颗粒结合的碳质气溶胶（CA）作为元素碳（EC）和有机碳（OC）进行定量协议。对大小分级的PM中不同温度碳组分（OC1-OC4，EC1-EC3和PyO）的浓度进行了评估，以区分OC和EC相关性以及char-EC和烟灰EC之间的相关性。结果表明，生物质燃烧，机动车和二次有机气溶胶（SOC）均造成了颗粒级​​分的PM。全年的OC / EC比率在2.90至4.30之间，PM _2.5-10的比率最高，除了露天生物量燃烧期。发现CA的浓度在季风前季节增加，并且在PM _0.5-1.0的峰值处出现。在季风前季节，PM从泰国西南部的印度尼西亚向泰国南部的远程运输更加明显。来自印度尼西亚生物质燃烧的运输烟羽可能会增加精细级分（PM _0.5-1.0和PM _1.0-2.5）和粗级分（PM _2.5-10和PM _{> 10}）中OC和EC的浓度。在季风前季节，PM _0.1中的OC分数也受到运输羽流的显着影响。良好的OC和EC相关性（R²  = 0.824–0.915）中的细颗粒级分表明它们具有共同的来源，例如化石燃料燃烧。但是， 较粗颗粒之间的相关性较低和中等（R ² = 0.093–0.678），表明它们在旱季和季风季节的排放源格局更为复杂。这表明将排放控制策略集中在泰国南部不同PM粒度上的重要性。