| 南京大气气溶胶混合态与云凝结核活化特征研究 |
| 摘要点击 1800 全文点击 1314 投稿时间：2015-09-19 修订日期：2015-12-10 |
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| 中文关键词 气溶胶 云凝结核活性 混合态 黑碳 临界过饱和度 |
| 英文关键词 aerosol CCN activity mixing state black carbon critical supersaturation |
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| 中文摘要 |
| 于2014年9月11~18日期间,在南京市气象局利用云凝结核计数器(CCNC)、气溶胶质量分析仪(APM)和扫描电迁移率粒径谱仪(SMPS)对气溶胶的分档云凝结核活性以及混合状态进行观测. 结果表明,观测期间颗粒物混合状态以内部混合为主,76、111、138和181 nm颗粒物中,黑碳(BC)所占质量分数分别为5.4%、10%、10.7%和6.7%,而含BC核的颗粒物占总颗粒物数量的百分比分别为51%、57%、70%和59%,表明BC是大气中重要的凝结核,对大气颗粒物的数量有重要贡献. 观测到的少数外混状态的颗粒物主要集中在111 nm和138 nm. 76、111、138和181 nm颗粒物的临界过饱和度分别为0.25%、0.13%、0.06%和0.015%. 降雨和灰霾对云凝结核活性影响较大,雨天、晴天和霾天的气溶胶吸湿性系数κ分别为0.37、0.29、0.39. 气溶胶颗粒物的密度和云凝结核活性受化学组分影响明显,相对于晴天,霾天颗粒物中无机盐含量较高、有机物含量较少,对应的颗粒物密度较高、云凝结核活性较强. |
| 英文摘要 |
| During 11-18 September 2014, the size-resolved aerosol Cloud Condensation Nuclei (CCN) activity and mixing state were measured using Cloud Condensation Nuclei Counter (CCNC), Aerosol Particle Mass (APM) and Scanning Mobility Particle Sizer (SMPS). The results showed that aerosols mainly existed as an internal mixture. For 76, 111, 138 and 181 nm particles, black carbon (BC) accounted for 5.4%, 10%, 10.7% and 6.7% of the particle mass, but as high as 51%, 57%, 70% and 59% of the particle number concentrations, respectively, suggesting that BC was a type of important condensation nuclei in the atmosphere and made significant contributions to particle numbers. The occasionally observed external mixtures were mainly present in 111 and 138 nm particles. The critical supersaturation was 0.25%, 0.13%, 0.06% and 0.015% for 76, 111, 138 and 181 nm particles, respectively. Precipitation and haze had significant effects on the particle CCN activity. The hygroscopicity parameter κ was 0.37, 0.29 and 0.39 in rainy, clear and hazy days, respectively. Particle density and CCN activity were impacted by chemical compositions. Compared with clear days, higher contents of inorganic salts and lower contents of organics were found on hazy days, accompanied by lower particle density and higher CCN activity. |
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