黄山夏季气溶胶光学特性观测分析

利用2011年6~8月黄山光明顶气溶胶光学参数的观测资料,分析了气溶胶各光学参数的逐日变化和非降水条件下日变化特征,并结合Hysplit后向轨迹模式,探讨了不同气团影响下气溶胶光学参数的变化特征.结果表明:黄山光明顶气溶胶消光作用以散射为主,观测期间气溶胶散射系数(σsc)、吸收系数(σab)、单次散射反照率(SSA)和后向散射比(BSR)的平均值(标准差)分别为62.59(49.17) Mm-1、5.49(3.67) Mm-1、0.89(0.04)和0.13(0.02);各光学特征量具有明显日变化特征.σsc、σab和SSA白天高,夜间低, BSR则相反,边界层活动是影响光明顶气溶胶光学性质日变化的主要因素.聚类分析结果显示光明顶主要受西北方大陆性气团、西南方大陆性气团以及东南方海洋性气团的影响.不同气团影响下,气溶胶光学参数有很大差异,其中北方大陆性气团影响下的σab、σsc和SSA最大,东南方海洋性气团影响下最小,表明大陆性气团传输过程中二次气溶胶生成的影响较为明显.

Observational study of aerosol optical properties in summer in Mt. Huang

Characteristics of the time series of daily average and diurnal variation of aerosol optical properties under the condition of non-rain were analyzed with the scattering and dabsorption coefficients of atmospheric aerosols obtained during July to August in 2011at the Guangmingding meteorological observatory on Mt. Huang. And the analysis of aerosol optical properties in different air masses was conducted by using Hysplit model. The results showed that the aerosol scattering played a dominant role in the total extinction. The average value (standard deviation) of the scattering coefficients (σsc), absorption coefficients (σab), single scattering albedo (SSA) and backscattering ratio (BSR) were 62.59 (49.17) Mm-1, 5.49 (3.67) Mm-1, 0.89 (0.04) and 0.13 (0.02), respectively. σsc , σab and SSA were higher during the day and lower at night while backscattering ratio was the opposite. The mainly influencing factor of the diurnal variation of aerosol optical properties were the activity of the boundary layer and the mountain and valley winds. There were a marked difference in the aerosol properties at different air masses. The highest value of the cluster-mean of σsc, σab and SSA appeared in the air masses from northwest (continental air mass) and the lowest value appeared in the air masses from southwest (marine air mass). The results indicated that the substantial secondary aerosol production was the main influencing factor during the long-range transport.