阿克达拉大气本底站气流轨迹模拟研究

Simulation on Air Flow 3-Dimension Trajectories of the Boundary Layer at Akerdala Background Atmosphere Station

利用1994—2002年NCEP再分析资料和HYSPLIT v4.7轨迹模式模拟了阿克达拉大气本底站的气团三维后向轨迹;采用簇分析方法对计算出的数千条后向轨迹进行了聚类归并,得到反映气流轨迹主要特征的数条轨迹;按垂直层次和季节分别作图,并进行分析。主要研究了该站近9a来不同季节距地面100m和1 000m的近地面边界层气流轨迹的特征、各方向轨迹出现的频数及当地天气形势和地面天气系统与气流轨迹的关系;并且把该地的轨迹与地面观测和附近气象站的探空观测历史风向玫瑰图作了对比。揭示了该站气流轨迹的季节分布特征,天气系统的位置和移动路径以及大地形对轨迹的影响。结合该站周边城镇的分布和发展规模以及气团移动的轨迹,分析对阿克达拉大气本底站的可能影响,为建立区域大气本底站提供科学的选址依据;为今后在该站开展进一步的研究提供近地层大气气团移动方向和速度背景参考资料;同时,通过实例把轨迹模式模拟方法予以简介,希望其在气体污染物和沙尘的溯源与追踪研究以及对空气污染敏感设施站址的选择、具有污染排放源设施建设的环境评价中得到应用。

According to the re-analyzed data from NCEP during the period of 1994-2002 and the simulation of the HYSPLIT v4.7 Model on 3-dimension back trajectories of air mass at Akerdala station, several trajectories reflecting the main characteristics of air flow were obtained based on the classification of cluster analysis on the thousands of back trajectories. Plotted and analyzed by vertical layers and seasons, the features of air flow trajectories in boundary layer inside 100 m and 1 000 m above ground in different seasons were mainly studied during the nine years, as well as the frequencies of different directions and the relations between local weather situation, ground weather system and air flow trajectories. Contrasted with the wind rose curves of meteorological stations nearby, the seasonal features of air flow trajectories, the positions of weather system and their moving routes were revealed. Combined with the distribution and development of the surrounding cities and the trajectories of air mass, it has been analyzed the potential influences on the Akerdala background atmosphere station. So the scientific evidences for founding regional background atmosphere stations, meanwhile, the background data on local direction and velocity of air mass movement near surface for further research were provided. At the same time, it has been introduced the simulation method on HYSPLIT v4.7 Model through examples. And it is hoped to be used in research on gas pollutants and sand-dust tracing to the source, sites choice of facility station that are sensitive to air pollution, as well as environmental appraisal on the facility construction of source pollutants discharge.