Hydroxy fatty acids in marine aerosols as microbial tracers: 4-year study on β- and ω-hydroxy fatty acids from remote Chichijima Island in the western North Pacific
Hydroxy fatty acids in marine aerosols as microbial tracers: 4-year study on β- and ω-hydroxy fatty acids from remote Chichijima Island in the western North Pacific
复制标题
海洋气溶胶中的羟基脂肪酸作为微生物示踪剂：对北太平洋西部偏远父岛的 β- 和 ω- 羟基脂肪酸进行了 4 年研究
DOI：
10.1016/j.atmosenv.2015.05.038
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Kimitaka Kawamura
中科院分区：
文献类型：
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作者：
Poonam Tyagi;Yutaka Ishimura;Kimitaka Kawamura
对这些样品分别进行了β-和ω-羟基脂肪酸(FAs)作为革兰氏阴性细菌和高等植物的陆地生物标志物的调查。β-羟基(C8-C31)和ω-羟基(C11-C28)FAs的平均浓度表现出明显的季节变化，春季和冬季的最大值分别为300pg/m−3和650pg/m−3。气团返回轨迹清楚地表明，冬季至春季期间，大陆从亚洲流出，而海洋气团在夏季至秋季占主导地位，在千岛上空。值得注意的是，在研究期间，受污染的(大陆)气团和未受污染的(海洋)气团之间，大气中β-羟基脂肪酸的丰度以及估计的GNB质量浓度没有明显差异。然而，通过对污染大陆大气中β-羟基脂肪酸的聚类分析，观测到的相对来源强度在不同季节之间存在显著差异(冬季：98%，春季：63%，夏季；11%，秋季：26%)。此外，在C数优势方面，受污染的大陆气团和原始海洋气团之间存在明显的差异。这些结果对评估开阔海洋上大陆流出的细菌和植物类脂在大气中的传输具有重要意义。
To better understand the long-range atmospheric transport of microbial aerosols from Asia to the western North Pacific, marine aerosols were collected from Chichijima Island (27°04′N; 142°13′E) on a biweekly basis during 1990–1993. These samples were investigated for β– and ω–hydroxy fatty acids (FAs) as terrestrial biomarkers of Gram-negative bacteria (GNB) and higher plants, respectively. The average concentrations of β–hydroxy (C8–C31) and ω–hydroxy (C11–C28) FAs show pronounced seasonal variability with maxima in spring (300 ± 70 pg m−3) and winter (650 ± 330 pg m−3), respectively. Airmass back trajectories clearly indicate the continental outflow from Asia during winter to spring, whereas maritime airmasses dominate in summer to autumn over Chichijima. It is noteworthy that atmospheric abundances of β–hydroxy FAs and, thus, the estimated mass concentration of GNB have not been significantly varied between polluted (continental) and pristine (oceanic) airmasses during the study period. However, the relative source strength observed from cluster analysis of β–hydroxy FAs in the polluted continental airmassess vary significantly among seasons (winter: 98%, spring: 63%, summer; 11%, autumn: 26%). In addition, there were distinguishable differences between polluted continental and pristine maritime airmasses with regard to C-number predominance. The even C-number predominance of β– and ω–hydroxy FAs (∼80 and 98% of total mass concentration, respectively) in marine aerosols could be due to their significant contribution from GNB, terrestrial plants and soil microorganisms. These results have implications towards assessing the atmospheric transport of bacterial and plant lipids in the continental outflow over the open ocean.