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Seasonal variation of levoglucosan in aerosols over the western North Pacific and its assessment as a biomass-burning tracer
| Title: | Seasonal variation of levoglucosan in aerosols over the western North Pacific and its assessment as a biomass-burning tracer |
| Authors: | Mochida, Michihiro Browse this author | | Kawamura, Kimitaka Browse this author →KAKEN DB | | Fu, Pingqing Browse this author | | Takemura, Toshihiko Browse this author |
| Keywords: | Levoglucosan | | Biomass-burning aerosol | | Long-range transport | | Organic carbon | | Molecular marker |
| Issue Date: | Sep-2010 |
| Publisher: | Elsevier |
| Journal Title: | Atmospheric Environment |
| Volume: | 44 |
| Issue: | 29 |
| Start Page: | 3511 |
| End Page: | 3518 |
| Publisher DOI: | 10.1016/j.atmosenv.2010.06.017 |
| Abstract: | Levoglucosan is considered as a useful molecular tracer of biomass-burning aerosols in the atmosphere. To characterize the seasonal variation of its concentrations over the Pacific Ocean and to assess its usefulness as a tracer after long-range transport, we investigated long-term variations of levoglucosan over Chichi-jima in the western North Pacific, from 2001 to 2004. Organic carbon (OC), elemental carbon (EC) and D-glucose were analyzed for comparison. The seasonal variation of levoglucosan concentrations shows a maximum in the winter, which is consistent with the enhanced Asian outflow to the Pacific indicated by backward air-mass trajectories. The concentration levels of levoglucosan estimated from global aerosol model outputs in the winter are, on average, comparable to the observed levels, suggesting that a considerable fraction of levoglucosan did not decompose during long-range transport from the Asian continent by westerly/northwesterly winds. This result is supported by comparable ratios of levoglucosan to EC in Chichi-jima and the East Asian coastal region. Conversely, the measured concentrations of levoglucosan in the summer are significantly lower than the modeled one. This implies a degradation of levoglucosan in the air masses that stagnated over the Pacific, although uncertainties in the model estimate may also be partly responsible for this discrepancy. One possible degradation pathway is oxidation by OH radicals; the contribution of acid-catalyzed reactions needs further investigation. |
| Type: | article (author version) |
| URI: | http://hdl.handle.net/2115/49421 |
| Appears in Collections: | 低温科学研究所 (Institute of Low Temperature Science) > 雑誌発表論文等 (Peer-reviewed Journal Articles, etc)
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Submitter: 河村 公隆
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