Kim Jeongbeen, Ha Yoonkyeong, Cho Kyungil, Lee Soodong, Jung Jinsang, Lee Seung-Bok, Lee Ji Yi, Song Mijung, Jang Kyoung-Soon, Lee Kwangyul, Ahn Junyoung, Kim Changhyuk
School of Civil and Environmental Engineering, Pusan National University, Busan 46241, Republic of Korea.
Korea Research Institute of Standards and Science (KRISS), Daejeon 34113, South Korea.
Sci Total Environ. 2024 May 10;924:171516. doi: 10.1016/j.scitotenv.2024.171516. Epub 2024 Mar 7.
The hygroscopicity of PM particles plays an important role in PM haze in Northeast Asian countries by influencing particle growth and chemical composition. New particle formation (NPF) and atmospheric volatile organic compounds (VOCs) are factors that influence particle hygroscopicity. However, the lack of real-time hygroscopicity measurements has deterred the understanding of their effects on particle hygroscopicity. In this study, two intensive monitoring campaigns were conducted during the summer of 2021 and spring of 2022 using real-time aerosol instruments, including a humidified tandem differential mobility analyzer (HTDMA), in Seosan, Republic of Korea. The hygroscopicity parameter κ was calculated from the real-time HTDMA measurement data (κ). The diurnal variations in κ exhibited strong inverse linear correlations with the total concentration of VOCs (C) during the two campaigns. The higher atmospheric C in summer increased the growth rate of the particle diameter from 10 to 40 nm (6 nm/h) compared with that in spring (2.7 nm/h), resulting in a faster change in κ for 40-nm particles in summer than in spring because of the increase in organic matter in the chemical compositions of particles. In addition, NPF events introduced additional tiny fresh particles into the atmosphere, which reduced the κ of 40-nm particles and increased the intensity of the less hygroscopic peaks (κ < 0.1) of κ-probability density functions (κ-PDF) in NPF days. However, 100-nm particles exhibited fewer changes in κ than 40-nm particles, resulting in additional dominant hygroscopic peaks (κ ∼ 0.2) of κ-PDFs in both NPF and non-NPF days. When κ values measured in Seosan were compared with those in other Northeast Asian countries in the literature, the κ values for 40-nm particles were lower than those (κ > 0.2) measured in Beijing and Guangzhou, but those for 100-nm particles were close to those measured in the two cities.
颗粒物的吸湿性通过影响颗粒增长和化学成分，在东北亚国家的细颗粒物霾中起着重要作用。新粒子形成（NPF）和大气挥发性有机化合物（VOCs）是影响颗粒吸湿性的因素。然而，缺乏实时吸湿性测量阻碍了对它们对颗粒吸湿性影响的理解。在本研究中，于2021年夏季和2022年春季在韩国瑞山市使用包括加湿串联差分迁移率分析仪（HTDMA）在内的实时气溶胶仪器进行了两次密集监测活动。根据实时HTDMA测量数据（κ）计算吸湿性参数κ。在这两次活动期间，κ的日变化与VOCs的总浓度（C）呈现出强烈的负线性相关性。与春季（2.7纳米/小时）相比，夏季较高的大气C使粒径从10纳米增长到40纳米的速率增加（6纳米/小时），由于颗粒化学成分中有机物的增加，导致夏季40纳米颗粒的κ变化比春季更快。此外，NPF事件向大气中引入了额外的微小新鲜颗粒，这降低了40纳米颗粒的κ，并增加了NPF日κ概率密度函数（κ-PDF）中吸湿性较低峰（κ<0.1）的强度。然而，100纳米颗粒的κ变化比40纳米颗粒少，导致在NPF和非NPF日的κ-PDF中都出现了额外的主要吸湿性峰（κ∼0.2）。当将瑞山市测量的κ值与文献中其他东北亚国家的κ值进行比较时，40纳米颗粒的κ值低于在北京和广州测量的值（κ>0.2），但100纳米颗粒的κ值与这两个城市测量的值接近。
