Investigation of Biomass Burning Chemical Components over Northern Southeast Asia during 7-SEAS/BASELInE 2014 Campaign

Chanakarn  Khamkaew; Somporn  Chantara; Rungruang  Janta; Shantanu Kumar  Pani; Tippawan  Prapamontol; Sawaeng  Kawichai; Wan  Wiriya; Neng-Huei  Lin

doi:10.4209/aaqr.2016.03.0105

Investigation of Biomass Burning Chemical Components over Northern Southeast Asia during 7-SEAS/BASELInE 2014 Campaign

Chanakarn Khamkaew¹, Somporn Chantara ¹^,2, Rungruang Janta¹, Shantanu Kumar Pani³, Tippawan Prapamontol⁴, Sawaeng Kawichai⁴, Wan Wiriya¹^,2, Neng-Huei Lin¹^,3

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¹Environmental Science Program, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
²Environmental Chemistry Research Laboratory, Chemistry Department, Faculty of Science, Chiang Mai University, Chiang Mai 50200, Thailand
³Department of Atmospheric Science, National Central University, Chung-Li 32001, Taiwan
⁴Environment and Health Research Unit, Research Institute for Health Sciences, Chiang Mai University, Chiang Mai 50200, Thailand

Received: March 4, 2016
Revised: August 30, 2016
Accepted: August 31, 2016
Download Citation: ||https://doi.org/10.4209/aaqr.2016.03.0105

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Cite this article:
Khamkaew, C., Chantara, S., Janta, R., Pani, S.K., Prapamontol, T., Kawichai, S., Wiriya, W. and Lin, N.H. (2016). Investigation of Biomass Burning Chemical Components over Northern Southeast Asia during 7-SEAS/BASELInE 2014 Campaign. Aerosol Air Qual. Res. 16: 2655-2670. https://doi.org/10.4209/aaqr.2016.03.0105

HIGHLIGHTS

PM_2.5 concentrations of near- and far- BB source locations were well correlated.
Levoglucosan, elemental and ion composition of PM_2.5 aerosols were analyzed.
SO₄^2–, NO₃^–, Na⁺, K, Al and Mg were major ions and elements bounded with PM_2.5.
Biomass burning was major source of ambient PM_2.5 during smoke haze episode.
Major air masses approaching to both sampling sites came from southwest direction.

ABSTRACT

This study investigates the chemical components of biomass burning (BB) aerosols obtained from Doi Ang Khang (DAK; near BB source) and Chiang Mai University (CMU; an urban location) over northern Southeast Asia in dry season (March to mid-April) 2014. PM_2.5 (particulate matter with an aerodynamic diameter less than or equal to 2.5 µm) samples were collected over a 24-h sampling period as a part of the Seven South East Asian Studies (7-SEAS)/BASELInE (BB Aerosols & Stratocumulus Environment: Lifecycles & Interactions Experiment) campaign. The collected aerosols were analyzed for mass concentrations of ions, metals and levoglucosan. The influence of air mass movements on aerosol species was also analyzed. The average PM_2.5 mass concentrations at DAK (80.8–83.3 µg m^–3) and CMU (90.7–93.1 µg m^–3) were not significantly different (p > 0.05) and well correlated (r = 0.8), and likely originated from similar source origins. The number of fire hotspots was particularly high during 20–21 March (greater than 200) and, consequently, peaks of PM_2.5 were recorded at both sites. The most abundant elements at both sampling sites were K (49–50% of total elements), Al (26–31%), Mg (16%) and Zn (4–7%), whereas SO₄^2– (30–38% of total ions), NO₃^– (13–20%), Na⁺ (16–20%) and NH₄⁺ (14–15%) were the most abundant ions. Concentrations of levoglucosan and K⁺ (BB tracers) were well correlated (r = 0.5 for CMU and 0.7 for DAK) confirming that the PM_2.5 detected in these areas were mainly influenced by BB activity. Principal component analysis (PCA) revealed that BB, road traffic, agricultural activity and soil re-suspension were plausible sources of PM_2.5 over the study locations. Apart from local sources, the influence of long-range transport was also investigated by way of three-day backward trajectory analysis.