Water-soluble organic nitrogen in the aerosols and rainwater at an urban site in Japan: Implications for the nitrogen composition in the atmospheric deposition
Water-soluble organic nitrogen in the aerosols and rainwater at an urban site in Japan: Implications for the nitrogen composition in the atmospheric deposition
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DOI：
10.1016/j.atmosenv.2018.07.056
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发表时间：
2018-10
影响因子：
5
通讯作者：
K. Matsumoto;Fumihiko Takusagawa;Haruka Suzuki;K. Horiuchi
中科院分区：
文献类型：
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作者：
K. Matsumoto;Fumihiko Takusagawa;Haruka Suzuki;K. Horiuchi
同时对大气气溶胶和雨水中的水溶性有机氮（WSON）进行了测量，以阐明大气WSON的沉积途径。在气溶胶中，约10%的水溶性总氮（WSON）是以有机形式存在的，并且大部分（平均约81%）的WSON分布在精细模式范围内。细模式的WSON的浓度与细颗粒的酸度，表明在酸性细颗粒的WSON的二次生产。另一方面，有人认为粗模式WSON来自生物颗粒，例如植物碎片，尽管其浓度较低且广泛分散。从颗粒WSON的浓度和干沉积速度估计的WSON的干沉积量表明，几乎所有的颗粒WSON的干沉积是来自于粗模颗粒。细模粒子对干沉积的贡献可以忽略不计。在大量沉淀中约10%的水分以有机形式存在。WSON的整体沉积量在很大程度上取决于降雨量和粗模式WSON浓度。虽然干沉降约占总沉降量的30%，但湿沉降对WSON的沉降贡献显著，尤其是在雨季。春季至秋季，湿沉降是WSON的主要去除过程，而在冬季，干、湿沉降相当。
Simultaneous measurements of the water-soluble organic nitrogen (WSON) in the aerosols and rainwater were conducted to clarify the deposition pathway of the atmospheric WSON. In the aerosols, about 10% of the water-soluble total nitrogen (WSTN) was in an organic form, and a large portion (about 81% on average) of the WSON was distributed in the fine-mode range. Concentrations of the fine-mode WSON were associated with the acidity of the fine particles, suggesting the secondary production of the WSON in the acid fine particles. On the other hand, it was suggested that the coarse-mode WSON was derived from bio-particles, such as plant debris, although its concentrations were low and widely scattered. Dry deposition amounts of the WSON estimated from the concentrations and dry deposition velocities of the particulate WSON suggested that almost all of the dry deposition of the particulate WSON was derived from the coarse-mode particles. The contribution of the fine-mode particles to the dry deposition was negligible. About 10% of the WSTN in the bulk precipitation was in an organic form. The bulk deposition amounts of the WSON were largely dependent on the rainfall amounts and coarse-mode WSON concentrations. Although about 30% of the WSON in the bulk deposition was from the dry deposition, the wet deposition significantly contributed to the WSON deposition, especially in the rainy season. Wet deposition is the major removal process of WSON from spring to autumn; however, in winter, dry and wet deposition are comparable.