Simultaneous measurement of the water-soluble organic nitrogen in the gas phase and aerosols at a forested site in Japan
Simultaneous measurement of the water-soluble organic nitrogen in the gas phase and aerosols at a forested site in Japan
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DOI：
10.1016/j.atmosenv.2018.12.011
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发表时间：
2019-03
影响因子：
5
通讯作者：
K. Matsumoto;Y. Watanabe;K. Horiuchi;T. Nakano
中科院分区：
文献类型：
--
作者：
K. Matsumoto;Y. Watanabe;K. Horiuchi;T. Nakano
在日本的一个森林站点进行了为期两年的同时观测的气相和颗粒相的水溶性有机氮（WSON），以澄清气体和颗粒的WSON的产生机制和可能的来源。气溶胶中WSON的平均浓度为0.070 μg m− 3，范围从低于检测限（DL）的浓度到0.302 μg m−3。大部分（约73%）的颗粒WSON分布在细模范围（d < 2.0 μm）。气态WSON的平均浓度为0.041 μg m− 3，范围从低于DL的浓度到0.195 μg m−3。大气WSON中约37%分布在气相中，气态WSON中约59%为碱性。粗模态（d = 2.0-10 μm）WSON的季节变化不明显，夏季有所增加。其浓度仅与粗颗粒物中所测物种的WSOC浓度有显著相关性。悬浮的有机物质从主要来源，如植物残体，将是一个可能的来源，粗模式WSON。在精细模式范围内的WSON表现出明显的季节性，从春季到夏季的浓度增强。细模式的WSON浓度表现出很强的相关性与细颗粒的酸度和浓度的气态的基本WSON，这表明二次生产的WSON的酸性细颗粒从气态的基本WSON。气相中的基本WSON表现出与气态氨相似的季节变化趋势，并与温度密切相关，这表明气态基本WSON物种从陆地植被和/或土壤中的挥发具有温度依赖性。气态酸WSON的季节变化趋势不明确，其浓度与各参数之间均无显著相关性。目前还不能推断气态酸WSON的可能来源和化学形式。
A simultaneous observation of the water-soluble organic nitrogen (WSON) in the gaseous and particulate phases was conducted at a forested site in Japan for two years to clarify the generation mechanism and possible sources of the gaseous and particulate WSON. The concentration of the WSON in the aerosols was 0.070 μg m−3on average, ranging from the concentration below the detection limit (DL) to 0.302 μg m−3. A large portion (about 73%) of the particulate WSON was distributed in the fine-mode range (d < 2.0 μm). The concentration of the gaseous WSON was 0.041 μg m−3on average, ranging from the concentration below the DL to 0.195 μg m−3. About 37% of the atmospheric WSON was distributed in the gas phase, and about 59% of the gaseous WSON was basic. The coarse-mode (d = 2.0–10 μm) WSON showed an unclear seasonal trend, but increased in the summer. Its concentration showed a significant correlation only with the WSOC concentration among the measured species in the coarse aerosols. Suspended organic materials from primary sources, such as plant debris, would be a possible source for the coarse-mode WSON. The WSON in the fine-mode range showed a clear seasonality with enhanced concentrations from the spring to summer. The fine-mode WSON concentration showed a strong correlation with the acidity of the fine particles and the concentration of the gaseous basic WSON, suggesting the secondary production of the WSON in the acid fine particles from the gaseous basic WSON. The basic WSON in the gas phase showed a similar seasonal trend with the gaseous ammonia and strongly correlated with the temperature, which suggests the temperature dependent-volatilization of the gaseous basic WSON species from terrestrial vegetation and/or soil. The seasonal trend of the gaseous acid WSON was unclear, and its concentration did not show significant correlations with any parameters. The possible source and chemical forms of the gaseous acid WSON cannot be deduced at the present time.