| 摘要: | Biomass burning is recognized as one of the major factors affecting the regional-to-global weather and climate. The aerosol samples in this study were collected at Doi Ang Khang, Chiang Mai, Thailand from 23 Feb.–7 April 2013, corresponding to the monsoonal dry season and a maximum in agricultural and forest fire activity, by using MOUDI and Nano MOUDI. Characteristics and provenance of anhydrosugars (levoglucosan, mannosan and galactosan), sugars (galactose, glucose and mannose), sugar alcohols (glycerol, erythritol, xylitol, mannitol, myo-inositol and arabitol) in aerosol were investigated. Levoglucosan, glucose and myo-inositol were the most dominant anhydrosugar, sugar, and sugar alcohol, respectively. The dominant concentration peaks occurred for levoglucosan, glucose and myo-inositol were in the size ranges of 0.1–2.5 μm, 0.5–1.0 μm, and 0.2–1.0 μm, respectively. High concentration of levoglucosan was found at nighttime. The levoglucosan/mannosan mass ratio reported in this study was 3.21. Levoglucosan was found to be the most useful marker for biomass burning emitted from forest fire event in the mountain around Chiang Mai. Principle component analysis showed an accordant result indicated photochemical products from biomass burning, biogenic activity and vehicles exhaust were mainly sources of PM at Doi Ang Khang, Chiang Mai, Thailand. |
