Lü Rui, Yu Xingna, Jia Hailing, Xiao Sihan
Appl Opt. 2017 Sep 1;56(25):7002-7012. doi: 10.1364/AO.56.007002.
Ground-based characteristics (optical, type, size, and radiative properties) of aerosols measured between 2005 and 2012 were investigated over the Taihu rim region, which encompasses the cities of Shanghai, Suzhou, Wuxi, and Changzhou. The aerosol optical depth (AOD) showed a distinct seasonal variation with the highest value in summer and the lowest AOD in winter. There was broadest frequency distribution with a multimodal structure in summer. The Ångström exponent (AE) showed high values during spring; the relative frequency of AE in the range of 0-0.8 was 5-10 times greater than that of other seasons. The samples with high AOD and low AE were mainly observed in spring, which is attributed to the relative abundance of coarse particles. The monthly aerosol volume size distributions presented a bimodal structure (fine and coarse modes). The coarse mode was dominant during spring, while the fine mode was predominant in other seasons. The main aerosol type over Taihu during all the seasons was the mixed small-particle category, followed by the urban/industrial category. The minimum single scattering albedo (SSA) occurred in winter, suggesting that atmosphere aerosol had a higher absorption. All monthly averaged asymmetry factors (ASY) had positive values and no distinct seasonal variation. Both high real (Re) and imaginary (Im) parts of the refractive index occurred in winter. The atmospheric warming effect of aerosol was more significant in winter compared with other seasons, with the averaged atmosphere aerosol radiative forcing (ARF) and the corresponding atmospheric heating rate up to +69.46 W·m and 1.95 K·day, respectively. There existed a significant positive correlation between AOD and ARF (absolute value), and the correlation coefficients (r) exceeded 0.86 in each season with maximum r in summer. Along with the increasing of the SSA, the aerosol radiative forcing efficiency (absolute value) showed a decreasing trend at the bottom of the atmosphere and an increasing trend at the top of the atmosphere.
对2005年至2012年期间在太湖周边地区（包括上海、苏州、无锡和常州等城市）测量的气溶胶的地面特征（光学、类型、大小和辐射特性）进行了研究。气溶胶光学厚度（AOD）呈现出明显的季节变化，夏季最高，冬季最低。夏季频率分布最广，具有多峰结构。埃斯特朗指数（AE）在春季显示出高值；AE在0 - 0.8范围内的相对频率比其他季节大5 - 10倍。高AOD和低AE的样本主要在春季观测到，这归因于粗颗粒的相对丰度。每月气溶胶体积粒径分布呈现双峰结构（细模态和粗模态）。粗模态在春季占主导，而细模态在其他季节占主导。太湖地区所有季节的主要气溶胶类型是混合小颗粒类别，其次是城市/工业类别。最小单次散射反照率（SSA）出现在冬季，表明大气气溶胶具有较高的吸收。所有月平均不对称因子（ASY）均为正值，且无明显季节变化。折射率的实部（Re）和虚部（Im）在冬季均较高。与其他季节相比，气溶胶的大气变暖效应在冬季更为显著，平均大气气溶胶辐射强迫（ARF）和相应的大气加热率分别高达 +69.46 W·m² 和1.95 K·day⁻¹。AOD与ARF（绝对值）之间存在显著正相关，每个季节的相关系数（r）均超过0.86，夏季r最大。随着SSA的增加，气溶胶辐射强迫效率（绝对值）在大气底部呈下降趋势，在大气顶部呈上升趋势。
