Source apportionment of marine atmospheric aerosols in northern South China Sea during summertime 2018
Source apportionment of marine atmospheric aerosols in northern South China Sea during summertime 2018
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2018年夏季南海北部海洋大气气溶胶来源解析
DOI：
10.1016/j.envpol.2021.117948
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发表时间：
2021
影响因子：
8.9
通讯作者：
Zhao Jun
中科院分区：
文献类型：
--
作者：
Liang Baoling;Cai Mingfu;Sun Qibin;Zhou Shengzhen;Zhao Jun
海洋大气气溶胶在全球辐射平衡和气候变化中起着重要作用。因此，测量气溶胶的物理化学性质对于更好地了解其形成、老化过程和来源至关重要。然而，目前在南海北方亚微米颗粒物的高时间分辨率测量是稀缺的。在这项研究中，我们进行了一个基于船的巡航活动与扫描流动粒度仪和在线飞行时间气溶胶化学形态监测仪，以测量粒子数尺寸分布（PNSD）和亚微米粒子的化学组成在北方南海在2018年夏季。非难降解亚微米颗粒物（NR-PM 1）的平均浓度通常为9.11 ± 4.86 μg m−3;硫酸盐是最丰富的成分，其次是有机物、铵、硝酸盐和氯化物。采用正矩阵分解（PMF）方法对PNSD（粒径PMF）和有机气溶胶（OA PMF）进行分析，并进一步探讨了亚微米颗粒物的源解析。PMF的大小确定了四个因素，包括船舶废气，船舶影响海洋初级，大陆影响海洋次级，和混合积累气溶胶。数量浓度最丰富的颗粒物与船舶排放有关，约占44%。亚微米有机气溶胶是高度氧化的，并且由低挥发性氧化OA（LV-OOA，68%）、半挥发性OOA（SV-OOA，21%）和烃类OA（HOA，11%）组成。气团的后向轨迹表明，南海北方受印支半岛（ICP）气团影响的频率最高（64.7%），表明ICP的污染物在夏季对南海北方的大气有重要影响。因此，船基实地巡航测量可提供关于海洋大气气溶胶理化特性的宝贵数据，以更好地了解其来源。
Marine atmospheric aerosols play important roles in the global radiation balance and climate change. Hence, measuring physiochemical aerosol properties is essential to better understand their formation, aging processes, and source origins. However, high temporal resolution measurements of submicron particles are currently scarce in the northern South China Sea (SCS). In this study, we conducted a ship-based cruise campaign with a scanning mobility particle sizer and an online time of flight aerosol chemical speciation monitor to measure the particle number size distribution (PNSD) and the chemical composition of submicron particles over the northern SCS during summer 2018. The mean concentration of non-refractory submicron particulate matter (NR-PM1) was generally 9.11 ± 4.86 μg m−3; sulfate was the most abundant component, followed by organics, ammonium, nitrate, and chloride. Positive matrix factorization (PMF) analysis was applied to the PNSD (size PMF) and organic aerosols (OA PMF) and further investigated the source apportionment of the submicron particles. The size PMF identified four factors, including ship exhaust, ship influencing marine primary, continent affected marine secondary, and mixed accumulation aerosols. The most abundant particles in the number concentration were associated with ship emissions, which accounted for approximately 44 %. The submicron organic aerosols were highly oxidized and composed of low-volatility oxygenated OA (LV-OOA, 68 %), semi-volatile OOA (SV-OOA, 21 %), and hydrocarbon-like OA (HOA, 11 %). The backward trajectory of air masses showed that the northern SCS was most frequently (64.7 %) influenced by air masses from the Indo-Chinese Peninsula (ICP) during the campaign, implying that pollutants from ICP have a significant impact on the atmosphere of the northern SCS during summer. Thus, in situ ship-based cruise measurements can provide valuable data on the physiochemical characteristics of marine atmospheric aerosols to better understand their source origins.