HR: 17:00h
AN: A54A-05    [Abstracts]
TI: The Composition of Organic Aerosols in Southeast Asia During The 2006 Haze Episode
AU: * Jun, H
EM: g0500004@nus.edu.sg
AF: Division of Environmental Science and Engineering, National University of Singapore, Block EA, #03-12, 9 Engineering Drive 1, Singapore, 117576, Singapore
AU: Zielinska, B
EM: Barbara.Zielinska@dri.edu
AF: Division of Atmospheric Sciences, Desert Research Institute, 2215 Raggio Parkway, Reno, NV 89512, United States
AU: Balasubramanian, R
EM: eserbala@nus.edu.sg
AF: Division of Environmental Science and Engineering, National University of Singapore, Block EA, #03-12, 9 Engineering Drive 1, Singapore, 117576, Singapore
AB: The regional smoke haze in Southeast Asia is a recurring air pollution problem. Uncontrolled forest fires from land-clearing activities in Sumatra and Borneo, and to a lesser extent Malaysia, have occurred almost every dry season since the late 1990s. The smoke haze that took place in October 2006 shrouded an estimated 215,000 square miles of land on Indonesia's islands of Sumatra and Borneo, and persisted for several weeks. Satellite pictures showed numerous hotspots in both Sumatra and Kalimantan. The prevailing, South-Southwesterly, winds blew smoke from land and forest fires in central and south Sumatra to Singapore, affecting the regional air quality significantly and reducing atmospheric visibility. During this haze episode, we carried out an intensive field study in Singapore to characterize the composition of organic aerosols, which usually account for a large fraction of airborne particulate matter (PM). A total of 17 PM samples were collected while the hazy atmospheric conditions persisted in Singapore, and subjected to accelerated solvent extraction with dichloromethane and acetone. The extracted compounds were grouped into three major fractions (n-alkanes, polycyclic aromatic hydrocarbons, and polar organic compounds). More than 180 particulate-bound organic compounds were determined using gas chromatography/mass spectrometry (GC-MS). In order to investigate the origin of organic species, the carbon preference indexes as well as diagnostic ratios were used. The compositional differences of organic aerosols between the haze- and non- haze periods will be presented. The atmospheric implications of the composition of organic aerosols of biomass burning origin will be discussed. Keywords: smoke haze, organic aerosols, n-alkanes, polycyclic aromatic hydrocarbons, polar organic compounds
DE: 0305 Aerosols and particles (0345, 4801, 4906)
DE: 0345 Pollution: urban and regional (0305, 0478, 4251)
DE: 0365 Troposphere: composition and chemistry
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting