黄山顶夏季气溶胶数浓度特征及其输送潜在源区

利用轨迹聚类方法对2011年6~8月黄山光明顶的气团轨迹进行聚类分组,得到2011年夏季到达黄山顶的主要气团输送轨迹,结合黄山顶的气溶胶数浓度观测资料,分析不同类型输送轨迹与黄山顶积聚模态颗粒物数浓度的关系.利用潜在源贡献因子分析法PSCF(potential source contribution function analysis)定性分析了不同气团背景下黄山顶积聚模态颗粒物数浓度的潜在源区,最后结合浓度权重轨迹分析法CWT(concentration weighted field)定量分析不同潜在源区对黄山顶积聚模态颗粒物数浓度的贡献.结果表明,积聚模态颗粒物(0.5~1μm)数浓度约占0.5~20μm颗粒物数浓度的94.9%;黄山顶6~8月大陆气团的发生频率最高,约43.4%;影响黄山光明顶积聚模态颗粒物数浓度的潜在源区主要来自一些工业发达人口密集的城市群:湖北东部、安徽中部、河南、江西境内、两广交界处、湖南南部以及浙江北部地区.而垂直方向上,来自西北和西南方向高度约2~5km的自由对流层气团对黄山顶积聚模态粒子数浓度贡献较大.

Aerosol number concentration properties and potential sources areas transporting to the top of mountain Huangshan in summer

The trajectories of air masses reaching the summit of Mt. Huang, during June to August 2011, and their relationship with the number concentration of accumulation mode particles were analyzed based on a clustering technique combined with in situ measurements of the number concentration of aerosol particles. The possible sources of the accumulation mode aerosol particles over the summit of Mt. Huang under different air mass conditions were analyzed qualitatively with the method of potential source contribution function (PSCF). Finally, the contributions of different sources to the accumulation model particles over the summit of Mt. Huang were analyzed quantitatively with the method of concentration weighted field (CWT). The number concentration of accumulation mode particles (0.5~1μm) accounted for 94.9% of the particles in 0.5~20μm, and that the Summit of Mt. Huang was mainly influenced by continental air masses during the summer (43.4%). The potential sources of the accumulation mode particles over the summit of Mt. Huang were mainly from the most industrialized and heavily populated cluster of cities such as the eastern Hubei, central Anhui, Henan and Jiangxi province, the junction of Guangdong and Guangxi, southern Hunan and northern Zhejiang. The vertical cross sections showed that the accumulation mode particles over Mt. Huang were mainly transported from the free troposphere with the heights between approximately 2000m and 5000m and originated from the northwest and southwest pathways.