青岛大气气溶胶的浓度分布和干沉降的观测研究

Observation on Mass Concentration and Dry Deposition of Atmospheric Aerosols in Qingdao

根据青岛沙尘天气历史资料和近年来的青岛地面气溶胶观测资料 ,分析了青岛沙尘日数的长期变化趋势、季节变化特征以及气溶胶质量浓度、谱分布和干沉降的季节变化。分析结果表明 ,1 961～ 1 988年青岛沙尘日数呈波动变化 ,且幅度较大。 1 999年以来沙尘日数明显增加 ,且以浮尘天气为主。青岛在 1 961～ 2 0 0 1年扬沙日数年平均值为 1 83天 ,是北京同期的 1 3% ;年浮尘日数为 2 93天 ,是北京同期的 75 %。青岛沙尘发生日数主要集中在冬春季 ,春季最高 ,冬季次高 ;夏季没有沙尘天气 ,秋季很低。青岛气溶胶质量浓度有明显的季节变化 ,春季最高 ,冬季次之 ,秋季又次之 ,夏季最低。大流量观测的总悬浮颗粒物(TSP)年平均浓度为 1 77μgm- 3,安德森分级采样器观测的气溶胶质量浓度为 1 2 3μgm- 3,两者的差别与不同的观测时间和观测仪器有关。在 3月和 4月 ,粗细粒子的浓度相差很大 ,粗粒子分别占总浓度的 80 %和 62 %。青岛气溶胶沉降通量在 0 0 6～ 0 2gm- 2 d- 1 之间 ,平均值为 0 1 3gm- 2 d- 1 ,是北京沉降通量的 30 %。

Using history data of dust weather recorded from 1961～2001 and ground aerosol observation data, the trend of blowing-sand weather and its seasonal variation in the last 50 years in Qingdao is studied. The seasonal variation of total suspended particles (TSP), size distribution and dry deposition in Qingdao are also studied. It shows that the annual dust day varied much during 1961～1988. During 1989～1998, there were only 6 dust weather days. From 1999, dust days increased obviously. The average of annual dust days in the last 40 years is 1.83 day, which is 11% of Beijing. The order of dust days and mass concentration in Qingdao are listed from high to low: spring, winter, autumn, and summer. The averaged mass concentration by High-Volume instrument and Anderson cascade are 177 μg m -3 and 123 μg m -3 respectively, and the difference has relation to different sampling time and instrument. In March and April, mass concentration of coarse particles account for 80% and 62% respectively. The dry deposition flux in Qingdao is between 0.06～0.2 g m -2 d -1 with averaged value of 0.13 g m -2 d -1, which is 30% of Beijing.