北京大气热力和动力结构对污染物输送和扩散条件的影响

发布时间：2018-03-03 20:34

  本文选题：热力和动力结构　切入点：污染物输送和扩散　出处：《中国环境科学》2017年05期 　论文类型：期刊论文

【摘要】：利用北京、天津、河北地区常规气象数据、PM_(2.5)浓度、激光雷达数据,铁塔数据,结合风廓线数据对2015年10月13~17日发生在北京的空气重污染过程中大气热力和动力结构进行分析.结果表明,白天热力条件转好后,边界层低层垂直方向气流由上-下运动转变为倾斜运动,同时水平方向偏南风增大,高浓度气团向北京移动,污染物输送增强,造成这种空间结构的原因主要是热力条件加强后等温面由准东-西向转变为西北-东南向,由于山地加热激发的重力波振幅在白天增强,高空水平方向输送至北京的污染物在垂直方向出现向上和向下的传输.16日白天地面PM_(2.5)浓度的快速升高,这是在PM_(2.5)存在一定垂直交换的情况下,近地面偏南风输送的作用所致,以上出现的大气污染物输送和扩散机制可以在一定程度上解释区域重污染背景下,白天混合层高度升高而近地层PM_(2.5)浓度却随之升高的现象.
[Abstract]:Using the conventional meteorological data of Beijing, Tianjin and Hebei, the density of PMSP 2.5), the data of lidar, the data of iron tower, Combined with wind profile data, the thermal and dynamic structure of the atmosphere during the heavy air pollution from October 2015 to 17th in Beijing is analyzed. The results show that the thermal conditions are improved during the daytime. The vertical flow in the lower layer of the boundary layer changed from upper-bottom motion to tilting motion, while the horizontal direction of the southward wind increased, the high concentration of air mass moved to Beijing, and the transport of pollutants increased. The main reason for this spatial structure is that the isothermal surface changed from Zhundong to west-west to northwest to southeast after the thermal conditions were strengthened, and the amplitude of gravity wave excited by mountain heating increased during the day. The vertical and downward transport of pollutants from high altitude horizontal direction to Beijing. In 16th, the rapid increase of surface PMmatter 2.5) concentration is due to the effect of near-surface southward wind transport in the presence of a certain vertical exchange of PMT 2.5). The transport and diffusion mechanism of atmospheric pollutants mentioned above can explain to a certain extent the phenomenon that the height of the mixed layer increases during the day and the PMSP 2.5) concentration increases in the near strata under the background of heavy pollution in the region.
【作者单位】： 中国气象局北京城市气象研究所;京津冀环境气象预报预警中心;
【基金】：国家自然科学基金资助项目(41305130,41575010) 国家科技支撑计划资助项目(2014BAC23B03,2014BAC16B04) 北京市自然科学基金资助项目(8161004) 北京市科技计划课题(Z151100002115045)
【分类号】：X51
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本文编号：1562632