著者

Kawamura Kimitaka Izawa Yusuke Mochida Michihiro Shiraiwa Takayuki

出版者

Elsevier

雑誌

Geochimica et Cosmochimica Acta (ISSN:00167037)

巻号頁・発行日

vol.99, pp.317-329, 2012-12-15

被引用文献数

91

---

We successfully detected biomass burning tracers including levoglucosan and vanillic, p-hydroxybenzoic and dehydroabietic acids in an ice core (153 m long, ca. 300 years old) taken from Ushkovsky ice cap (altitude, 3903 m), the Kamchatka Peninsula, Northeast Asia. Concentrations of total organic carbon (TOC) were also determined in the ice core. Levoglucosan, which is produced by pyrolysis of cellulose and hemicellulose and thus is a general tracer of biomass burning, showed sporadic peaks in the years of 1705, 1759, 1883, 1915, 1949 and 1972, with the largest peak in 1949. However, its concentrations did not show a systematic increase in the last century although the concentration peaks seemingly corresponded to the higher ambient temperatures in the northern high latitudes. In contrast, dehydroabietic acid, a specific tracer of the pyrolysis of conifer resin, showed a gradual increase from the early 1900s to 1990s with a significant peak in 1970. Contributions of dehydroabietic acid to TOC also showed an increasing trend for the 20th century. Similarly, vanillic and p-hydroxybenzoic acids presented higher concentrations in the last half-century with sporadic peaks in 1705, 1759 and 1949. This study showed that general biomass burning tracers such as levoglucosan have been sporadically transported over the glacier of the Kamchatka Peninsula. In contrast, the ice core record of dehydroabietic acid indicated that fires of boreal conifer forest have more frequently and increasingly occurred in Far East and Siberia during the last century and transported to the Northwestern Pacific. The present study demonstrates that organic tracers of biomass burning preserved in ice core could provide historical records of biomass burning and boreal forest fires.

著者

Fu Pingqing Kawamura Kimitaka Kobayashi Minoru Simoneit Bernd R. T.

出版者

Elsevier

雑誌

Atmospheric Environment (ISSN:13522310)

巻号頁・発行日

vol.55, pp.234-239, 2012-08

被引用文献数

154

---

Sugars are important water-soluble organic constituents of atmospheric particulate matter (PM). In order to better understand the sources and seasonal variations of sugars in aerosols, primary saccharides (fructose, glucose, sucrose, and trehalose) and sugar alcohols (arabitol and mannitol), together with levoglucosan, have been studied in ambient aerosols at Gosan, Jeju Island in the western North Pacific, the downwind region of the Asian outflow, using gas chromatography-mass spectrometry. The results showed that the sugar composition varied seasonally with a total concentration range of 6.8-1760 ng m^[-3] (mean 246 ng m^[-3]). The total identified sugars had the highest concentration in April, the spring bloom season at Jeju Island, when sucrose contributed up to 80% of the total sugars. The dominance of sucrose was also detected in pollen samples, suggesting that pollen can contribute significantly to sucrose in aerosols during the spring bloom. The seasonal variation of trehalose is consistent with those of non-sea-salt Ca2+ and δ13C of total carbon with elevated levels during the Asian dust storm events. This study indicates that sugar compounds in atmospheric PM over East Asia can be derived from biomass burning, Asian dust, and primary biological aerosols such as fungal spores and pollen. Furthermore, this study supports the idea that sucrose could be used as a tracer for airborne pollen grains, and trehalose as a tracer for Asian dust outflow.