京津冀采暖期大气污染天气特征

选取2004—2006年京津冀地区采暖期155个区域大气污染日,对当日08:00(或前一日20:00)海平面气压场,结合高空环流特征进行了分析。对影响京津冀区域污染的天气形势划分为5种类型,即高压型、冷锋型、低压型、华北干槽型和均压场型,其中高压型最多,占40.0%。区域污染过程通常对应一次高空环流调整过程,连续性区域污染过程往往由多种天气型影响。地面辐合加上低层逆温和下沉运动阻碍污染物在水平和垂直方向的扩散,在污染源一定的条件下,稳定的大气层结和区域内特殊地形的影响是导致区域污染形成的重要原因。

Weather Characteristics of Regional Air Pollution during Heating Period in Beijing Tianjin Hebei Region

Based on the regional air pollution data during heating seasons from 2004 to 2006 in the Beijing-Tianjin -Hebei region,associated with the sea-level pressure fields and high circumfluence characteristics, the synoptic weather patterns for air pollution are divided into five types：high pressure,cold front,low pressure,North China dry-trough,and uniform pressure field.The high pressure type accounts for 40.0%.The regional air pollution process usually corresponds to an upper-level circulation adjustment process.Continuous regional air pollution processes are usually affected by various kinds of synoptic patterns.Under the conditions of the surface convergence,low-level inversion and vertical sinking motion, pollutants are impeded to diffuse.The stable atmospheric stratification and influence of special terrain are the important reasons for the regional air pollution.