| 南京北郊能见度变化中二次无机盐消光的重要作用 |
| 摘要点击 2319 全文点击 792 投稿时间：2017-07-21 修订日期：2017-09-13 |
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| 中文关键词 能见度 细粒子 化学组分 消光系数 二次无机盐 |
| 英文关键词 visibility fine particle chemical composition light extinction secondary inorganic salt |
| 作者 | 单位 | E-mail | | 于超 | 南京信息工程大学大气物理学院, 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | 1615653552@qq.com | | 于兴娜 | 南京信息工程大学大气物理学院, 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | | | 赵天良 | 南京信息工程大学大气物理学院, 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | tlzhao@nuist.edu.cn | | 张蕾 | 南京信息工程大学大气物理学院, 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | | | 马国煦 | 南京信息工程大学大气物理学院, 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | | | 王咏薇 | 南京信息工程大学大气物理学院, 中国气象局气溶胶与云降水重点开放实验室, 南京 210044 | |
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| 中文摘要 |
| 利用2013年5月~2014年5月的能见度和大气气溶胶化学组分资料，分析南京北郊能见度变化特征、气溶胶化学组分与能见度变化的关联及其对大气消光的贡献，识别在能见度变化中二次无机盐消光的重要作用.结果表明，观测期间平均能见度为（6.78±3.68）km，能见度存在显著的季节变化.粒径小于2.1 μm的细粒子对能见度降低有较大影响，SO42-、NO3-、NH4+和OC是细粒子主要成分，其中二次无机离子对重霾日能见度恶化具有重要贡献.利用修正的IMPROVE方程重建观测期间消光系数，均值为（527.2±295.2）Mm-1，PM2.1化学组分中硫酸铵、硝酸铵以及有机物对消光系数贡献最大，达到80.6%.尽管在清洁日（VR>10 km）有机物的消光贡献高达43.51%，但随着能见度降低，有机物消光贡献减少，二次无机盐组分消光贡献增加，在低能见度的重霾日（VR<5 km）二次无机盐消光贡献达到58.96%，表明二次无机盐消光对能见度恶化具有重要作用. |
| 英文摘要 |
| Observed data regarding the visibility and aerosol chemical composition from May 2013 to May 2014 were used to analyze the variation of visibility, the relationship between aerosol chemical composition and visibility variations, and their contributions to atmospheric light extinction. An important effect of secondary inorganic salt extinction on the visibility impairment was determined. The present study suggests that the average visibility during the observation period was (6.78±3.68) km, and there was obvious seasonal variation in the visibility. Fine particles with size less than 2.1 μm have a great influence on visibility, with the main chemical components of SO42-, NO3-, NH4+, and OC. The secondary inorganic ions make significant contributions to visibility degradation. The mean light extinction coefficient of Nanjing was (527.2±295.2) Mm-1, which was calculated by using the revised IMPROVE equation. Regarding the chemical composition of PM2.1, the most contributive species to the light extinction coefficient were ammonium sulfate, ammonium nitrate, and organic species, which accounted for 80.6%. Although the light extinction contribution of organic matter was as high as 43.51% on a clear day (VR>10 km), with the decrease of visibility, the extinction contribution of organic matter decreased, but the contribution of secondary inorganic salt increased. The contribution of extinction was 58.96% for heavy haze days with low visibility (VR<5 km). This proves that the secondary inorganic salt extinction plays a significant role in visibility impairment. |
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