Significant alteration in the hygroscopic properties of urban aerosol particles by the secondary formation of organics
Significant alteration in the hygroscopic properties of urban aerosol particles by the secondary formation of organics
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DOI：
10.1029/2007gl031310
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发表时间：
2008-01
影响因子：
5.2
通讯作者：
M. Mochida;T. Miyakawa;N. Takegawa;Y. Morino;K. Kawamura;Y. Kondo
中科院分区：
文献类型：
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作者：
M. Mochida;T. Miyakawa;N. Takegawa;Y. Morino;K. Kawamura;Y. Kondo
在2004年夏季的吸湿增长因子（g）测量的基础上，在东京的城市气溶胶粒子的吸湿性的时间变化进行了研究。对于100 nm的颗粒，当含氧有机物质量增加时（r = 0.76），观察到中等吸湿性（1.11 ≤ g < 1.29）颗粒的零星出现，这表明次生有机物的形成控制了这些颗粒的吸湿性。在白天的光化学活跃期，模式吸湿性的100 nm以上的颗粒g = 1.11迅速下降，在几个小时内。这是由于二次有机物凝结在预先存在的颗粒上，这些颗粒具有高度吸湿性（g ≥ 1.29），并且是从东京都市区以外地区输送来的。观察到的颗粒吸湿性的快速变化表明，次生有机物的冷凝以8-17 nm h−1的速率增加了干颗粒直径。
The temporal variation in the hygroscopicity of urban aerosol particles was investigated in Tokyo based on the hygroscopic growth factor (g) measurement in the summer of 2004. For 100 nm particles, sporadic appearance of intermediately hygroscopic (1.11 ≤ g < 1.29) particles was observed when the oxygenated organic mass increased (r = 0.76), suggesting that the formation of secondary organics governs the hygroscopicity of these particles. During a photochemically active period in the daytime, the mode hygroscopicity of 100 nm particles above g = 1.11 rapidly decreased in a few hours. This is explained by the condensation of secondary organics on pre‐existing particles that are highly hygroscopic (g ≥ 1.29) and are transported from outside the Tokyo metropolitan area. The observed rapid change in particle hygroscopicity suggests that the condensation of secondary organics increase the dry particle diameter at rates of 8–17 nm h−1.