Yu Xingna, Lü Rui, Kumar K Raghavendra, Ma Jia, Zhang Qiuju, Jiang Yilun, Kang Na, Yang Suying, Wang Jing, Li Mei
Key Laboratory of Meteorological Disaster, Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD)/Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing, 210044, China.
Guangzhou Hexin Analytical Instrument Company Limited, Guangzhou, 510530, China.
Environ Sci Pollut Res Int. 2016 Aug;23(15):15432-42. doi: 10.1007/s11356-016-6727-9. Epub 2016 Apr 27.
The ground-based characteristics (optical and radiative properties) of dust aerosols measured during the springtime between 2001 and 2014 were investigated over urban Beijing, China. The seasonal averaged aerosol optical depth (AOD) during spring of 2001-2014 was about 0.78 at 440 nm. During dust days, higher AOD occurred associated with lower Ångström exponent (AE). The mean AE440-870 in the springtime was about 1.0, indicating dominance of fine particles over the region. The back-trajectory analysis revealed that the dust was transported from the deserts of Inner Mongolia and Mongolia arid regions to Beijing. The aerosol volume size distribution showed a bimodal distribution pattern, with its highest peak observed in coarse mode for all episodes (especially for dust days with increased volume concentration). The single scattering albedo (SSA) increased with wavelength on dust days, indicating the presence of more scattering particles. Furthermore, the complex parts (real and imaginary) of refractive index showed distinct characteristics with lower imaginary values (also scattering) on dust days. The shortwave (SW; 0.2-4.0 μm) and longwave (LW; 4-100 μm) aerosol radiative forcing (ARF) values were computed from the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model both at the top of atmosphere (TOA) and the bottom of atmosphere (BOA) during dust and non-dust (dust free) days, and the corresponding heating rates and forcing efficiencies were also estimated. The SW (LW) ARF, therefore, produced significant cooling (warming) effects at both the TOA and the BOA over Beijing.
对2001年至2014年春季在中国北京城区测量的沙尘气溶胶的地面特征（光学和辐射特性）进行了研究。2001 - 2014年春季的季节性平均气溶胶光学厚度（AOD）在440纳米处约为0.78。在沙尘日期间，较高的AOD与较低的Ångström指数（AE）相关。春季的平均AE440 - 870约为1.0，表明该地区细颗粒物占主导。后向轨迹分析表明，沙尘是从内蒙古沙漠和蒙古国干旱地区传输到北京的。气溶胶体积粒径分布呈现双峰分布模式，在所有时段（特别是沙尘日体积浓度增加时），其最高峰出现在粗模态。沙尘日的单次散射反照率（SSA）随波长增加，表明存在更多散射粒子。此外，沙尘日折射率的复数部分（实部和虚部）表现出明显特征，虚部值较低（也是散射）。利用圣巴巴拉离散纵标大气辐射传输（SBDART）模型计算了沙尘日和非沙尘（无沙尘）日在大气顶（TOA）和大气底（BOA）的短波（SW；0.2 - 4.0微米）和长波（LW；4 - 100微米）气溶胶辐射强迫（ARF）值，并估算了相应的加热率和强迫效率。因此，SW（LW）ARF在北京的TOA和BOA均产生了显著的冷却（加热）效应。
