摘要
对北京ρ(PM10)日均值和华北地区气象资料的综合分析发现,北京夏季ρ(PM10)的变化过程与环境背景场组合系统明显相关,其典型的背景场演变过程为:①在ρ(PM10)上升阶段,副热带高压西伸较强,持续数天控制华北地区,具有均压和弱气压场的特征.在其控制下,受地形和周边边界层背景的影响,偏南气流将北京南部的污染物向北京输送和汇聚,ρ(PM10)呈逐日汇聚增长趋势.②冷锋逼近时的均压场和弱气压场是ρ(PM10)峰值出现的背景.③在冷锋后部的大陆高压前锋造成较强的区域性输送过程,而冷锋附近形成的湿沉降使ρ(PM10)下降,因此在强区域性输送过程与明显降水终止后常出现ρ(PM10)谷值.统计分析表明,北京夏季环境污染过程与大尺度环境背景场组合系统及其配置的污染物输送通道演变有明显的同步特征.该类组合系统所配置的背景场及其同步环境污染演变过程的特征具有普遍规律性,可为奥运期间环境污染过程的预测和控制提供参考.
Based on the analysis of Beijing daily average data of PM10 and meteorological data of North China, obvious correlation between the variation of summer PM10 mass concentration in Beijing and the environment background compound system was found. The typical background pressure field evolved as follows： ① The horse latitude high continued controlling North China for several days during rise stage, and the pressure field was homogeneous and weak. Under the control of horse latitude high, influenced by terrain, boundary layer, pollutant transport and convergence by south current, mass concentration of PM10 increased day by day. ② Homogeneous and weak pressure field in front of the cold front resulted in the peak value. ③ Behind the cold front, regionally obvious transport process was created by Mongolia high pressure, and the wet sedimentation near the cold front resulted in the decrease of PM10 mass concentration. In this way, regional strong transport process and obvious precipitation often gave the birth of the valley value of PM10 According to statistic analysis, the evolvement of pollutant transport pathway and summer environment process in Beijing as well as large-scale environment background had obvious synchronous characteristics. The synchronic characteristic of background field under this kind of compound system and the pollution process was general, which would help to forecast and control the environment process during the Olympic Games period in Beijing.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2007年第5期12-19,共8页
Research of Environmental Sciences
基金
国家重点基础研究发展计划(973)项目(2005CB724201)
关键词
PM10
环境背景过程
副热带高压
湿沉降
PM10
environment background process
horse latitude high
wet sedimentation
