中国3个AERONET站点气溶胶微物理特性分析及比较

选取中国地区区域代表性较强且观测时间序列较长的3个AERONET站点(SACOL、香河和太湖),分析了其气溶胶微物理参数特征. 香河和太湖多年平均气溶胶光学厚度(AOD)分别为0.67±0.66和0.72±0.44,是SACOL AOD平均值(0.38±0.27)的近2倍,且AOD变化范围较大. SACOL春冬季AOD较大,夏秋季AOD较小;而香河和太湖夏春季较大,秋冬季较小.结合尺度分布、体积浓度等参数特征说明沙尘是SACOL春季最主要的气溶胶类型,香河春季受沙尘的影响也较严重,而太湖受沙尘影响的频率较香河要小的多;香河和太湖AOD最大值出现月份与细模态粒子体积浓度最大值出现月份一致,是由于细模态粒子的消光效率是粗模态粒子的3~4倍.细模态体积比(Vf/Vt)的年变化趋势与?ngstr?m波长指数(?)的年变化趋势相似,Vf/Vt和?均可以用来分析粒子尺度大小的年变化特征.但?1.7时,Vf/Vt大于0.6,以细模态粒子为主;而0.75

Analysis and comparison of the aerosol microphysical properties at three AERONET sites in China

The microphysical parameter characteristics of aerosol were analyzed at the AERONET stations located in SACOL, Xianghe and Taihu. The results showed that the annual average AOD at Xianghe and Taihu stations were 0.67±0.66 and 0.72±0.44, respectively, which were nearly 2times of the value of AOD at SACOL (0.38±0.27). The standard deviation presented a significant temporal variability. At SACOL, the higher value of AOD was found in the spring and winter, and the lower value of AOD was found in the summer and fall. However, At Xianghe and Taihu, the higher values of AOD were found in the spring and summer, and the lower values of AOD were found in the fall and winter. Combined with the size distribution, volume concentration of aerosol particles, it can be concluded that dust was the main type of aerosols at SACOL in spring. At Xianghe and Taihu stations, the types of aerosol were mainly fine mode particles in summer due to the gas-to-particle conversion process. We could observe that for the measurements with ?ngstr?m exponent (?0.4) was almost unavailable. According to analysis we could establish the limit of the fine particle predominance with ?>1.7approximately. But for 0.75