Dependence of CCN activity of less volatile particles on the amount of coating observed in Tokyo
Dependence of CCN activity of less volatile particles on the amount of coating observed in Tokyo
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DOI：
10.1029/2006jd007758
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发表时间：
2007-06
影响因子：
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通讯作者：
M. Kuwata;Y. Kondo;M. Mochida;N. Takegawa;K. Kawamura
中科院分区：
文献类型：
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作者：
M. Kuwata;Y. Kondo;M. Mochida;N. Takegawa;K. Kawamura
[1]发展了一种新的观测系统，可同时测量400°C下云凝结核（CCN）活动和气溶胶粒子的挥发性。使用CCN计数器和冷凝颗粒计数器测量CCN/CN比率，并且使用挥发性串联微分迁移率分析仪（VTDMA）测量挥发性。该系统串联连接到吸湿性串联微分迁移率分析仪，以测量吸湿性选择的颗粒的这些性质。这些仪器于2004年11月在东京部署。在东京，在400°C的非挥发性核心的主要部分已被发现是黑碳（BC）。因此，用VTDMA法测得的炭黑粒子数粒度分布代表了炭黑粒子的混合状态。吸湿性选择的颗粒的VTDMA测量显示，大多数吸湿性较低的颗粒挥发性较低，而吸湿性较高的颗粒挥发性较高。低挥发性颗粒的CCN/CN比值[（CCN/CN）LV]是根据低吸湿性颗粒的CCN活性和挥发性测量值估算的。(CCN SS = 0.5%时的（CCN/CN）LV与挥发引起的峰直径减小（Δdm）相关，Δdm = 10 nm时的（CCN/CN）LV几乎等于1。该结果表明，BC颗粒的CCN活性显著地取决于涂层的量。
[1] A novel observation system has been developed to measure cloud condensation nuclei (CCN) activity simultaneously with volatility of aerosol particles at 400°C. CCN/CN ratios were measured using a CCN counter and a condensation particle counter, and volatility was measured with a volatility tandem differential mobility analyzer (VTDMA). This system was connected to a hygroscopicity tandem differential mobility analyzer in tandem to measure these properties of hygroscopicity-selected particles. These instruments were deployed in Tokyo in November 2004. In Tokyo, the dominant fraction of nonvolatile cores at 400°C has been found to be black carbon (BC). Therefore the number size distribution measured by VTDMA represents the mixing state of black carbon particles. The VTDMA measurement of hygroscopicity-selected particles revealed that most of the less hygroscopic particles were less volatile, while more hygroscopic particles were more volatile. CCN/CN ratios of less volatile particles [(CCN/CN)LV] are estimated from CCN activity and volatility measurements of less hygroscopic particles. (CCN/CN)LV at SS = 0.5% is correlated with the decrease of peak diameter due to volatilization (Δdm), and (CCN/CN)LV is nearly equal to unity at Δdm = 10 nm. This result suggests that the CCN activity of BC particles significantly depends on the amount of coating.