Comparison of aerosol and cloud condensation nuclei between wet and dry seasons in Guangzhou, southern China
Comparison of aerosol and cloud condensation nuclei between wet and dry seasons in Guangzhou, southern China
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广州干湿季气溶胶和云凝结核的比较
DOI：
10.1016/j.scitotenv.2017.06.246
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发表时间：
2017
影响因子：
9.8
通讯作者：
He Qianshan
中科院分区：
文献类型：
--
作者：
Duan Junyan;Tao Jun;Wu Yunfei;Cheng Tiantao;Zhang Renjian;Wang Yanyu;Zhu Hailin;Xie Xin;Liu Yuehui;Li Xiang;Li Mei;He Qianshan
2015年7月至8月和2016年1月在广州市区同时测量了云凝结核（CCN）、凝结核（CN）和气溶胶化学成分，并据此进一步研究了气溶胶活化组分（NCCN/NCN）的季节变化及其相关影响因素。 NCN 通常在冬季（旱季）较高，而 NCCN 和 NCCN/NCN 通常在夏季（雨季）较高。特别是，冬季过饱和度较小 (SS < 0.2) 时，NCCN 和 NCCN/NCN 会低得多。尽管 NCCN 和 NCN 的日变化相似，但 NCCN/NCN 表现出相反的趋势，在中午、黄昏和午夜之前相对较低。除了颗粒物的尺寸和化学成分外，质量、气体前驱体、污染物输送、气象条件等因素也会导致NCCN和NCCN/NCN的变化。来自本地源或本地-海洋组合源的颗粒物对CN和CCN影响显着，而源自和穿越遥远污染区的污染物对NCCN和NCCN/NCN的影响较大。 CCN/CN。夏季无污染条件下、冬季有污染条件下NCN和NCCN相对较高，而NCCN/NCNi则相反。在各种污染条件下，夏季和冬季气溶胶CCN活性差异较大，特别是在薄雾或重霾时期。结果表明，人为污染物对气溶胶 CCN 活化具有重要影响。
Cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol chemical composition were measured simultaneously at an urban site of Guangzhou from July to August 2015 and in January 2016, and the seasonal variations of aerosol activated fractions (NCCN/NCN) as well as their relevant influence factors were further studied accordingly. NCNis generally higher in winter (dry season), whereas NCCNand NCCN/NCNare mostly higher in summer (wet season) instead. In particular, NCCNand NCCN/NCNare much lower at smaller supersaturation levels (SS < 0.2) in winter. In spite of similar diurnal variations for NCCNand NCN, NCCN/NCNindicates an opposite tendency, relatively lower at midday, dusk and before midnight. Other than the size of particles as well as their chemical composition, some other factors, such as mass, gas precursors, pollutant transportation, meteorological conditions, etc., also contribute to the variations of NCCNand NCCN/NCN.Particles from the local source or local-oceanic combination source cast influence on CN and CCN significantly, while the pollutants originating from and crossing over distant polluted areas contribute largely to CCN/CN. NCNand NCCNare relatively higher under pollution-free conditions in summertime and polluted conditions in wintertime, but NCCN/NCNis just the opposite. On various polluted conditions, aerosol CCN activities are greatly discrepant between summer and winter, especially during mist or heavy haze periods. The results imply that anthropogenic pollutants exert critical impacts on aerosol CCN activation.