论文总字数：21084字

目 录

1引言 1

2 研究方法 2

2.1 采样点与采样时间 2

2.2采样仪器 3

2.2.1 宽范围颗粒粒径谱仪 3

2.2.2 Anderson采样器 3

2.2.3 热/光碳分析仪 4

2.2.4 离子色谱仪 5

2.2.5 其它仪器及数据 6

2.3气溶胶消光系数、散射系数、吸收系数的计算 6

3 结果与讨论 9

3.1观测数据 9

3.2干态下黒碳的混合方式对气溶胶光学特性的影响 10

3.3环境相对湿度下黒碳的混合方式对气溶胶光学特性的影响 10

3.4相对湿度对消光系数、散射系数以及吸收系数的影响 11

3.5混合方式对气溶胶消光特性的影响 12

4 结论 14

参考文献 14

致谢 17

气溶胶混合方式对南京大气光学特性的影响

王雅娟

, China

Abstract:Elemental carbon aerosols have strong light-absorbing properties, affect the radiation transfer process and the local [size] energy balance, and thus affect the global climate system. The optical properties of aerosol particles vary with the elemental carbon mixing model, and their hygroscopic increasing characteristics are also different, especially in the case of very high relative humidity.. In this study, aerosol particle size distribution and chemical composition data observed from October 16 to November 14, 2013 at the field base in Nanjing, China and the meteorological roof of Nanjing university of information technology were used. Abstract The extinction, scattering and absorption characteristics of aerosol particles in three mixed models (internal mixing, external mixing, core-shell) were analyzed. In addition, changes in the optical properties of aerosol particles under three mixed modes have also been investigated. The research results show that the mixing model has little influence on extinction and scattering coefficient of aerosol particle optical properties, but has significant influence on absorption coefficient. under dry conditions, the absorption coefficient of core-shell model is 3.6 times higher than that of external mixing model, and that of internal mixing model is 4.6 times higher than that of core-shell model, and the size relationship is internal mixinggt; core-shell structuregt; external mixing. The increase in relative humidity has an important effect on the change of the extinction coefficient of aerosols, and the extinction coefficient will increase significantly. Regardless of the three mixing methods, the growth rates are close to each other. For the absorption coefficient, the mixing method will affect his growth rate, and the growth rate of other mixing methods is much less than the internal mixing.

Key words:Elemental carbon (EC); aerosol mixing method; extinction coefficient; absorption coefficient; relative humidity

1引言

气溶胶不仅具有重要的环境效应，还具有重要的气候效应，对其光学特性的研究对我们有着重要的意义。例如，气溶胶可以通过散射和吸收太阳的辐射来改变地球大气系统的行星反照率，从而影响地气系统的能量收支平衡；云凝结核和冰核也是大气气溶胶起到的作用之一，它有可能使得云滴的数密度增加，因此云滴平均半径变小，这很有可能增加云层对太阳光辐射的反射率或使云的维持时间加长或降水时间减少（毛节泰等.,2002），大气气溶胶的光学性质是大气科学领域的一个重要研究课题。这是因为气溶胶吸收和散射太阳辐射，这可以显著改变大气的能见度（Appel et al.,1985;Chan et al.,2017）对辐射传输过程和局地能量平衡产生影响(Han et al., 2009; Jacobson, 2001)，进而影响全球的气候系统（Bréon et al., 2002; Chou, 1980; Demott et al., 2003; Kratz and Cess, 1985）

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