沈阳2次重污染天气过程的风廓线雷达观测结果对比分析

Comparative analysis of wind profile radar observation results of two heavy pollution weather processes in Shenyang

为进一步研究重污染天气的形成机理,利用风廓线雷达资料、常规气象观测资料和大气污染物监测资料,对2015年11月6—10日和2019年3月2—6日(分别简称“过程Ⅰ”和“过程Ⅱ”)沈阳2次重污染天气过程进行对比分析,重点总结风廓线雷达直接探测产品和反演产品的演变特征。结果表明:过程Ⅰ,污染重,污染物浓度增速快,能见度持续偏低,下沉速度大,动力条件更稳定,且雷达接收的气象回波信号强。低层始终维持高强度的暖平流,为污染物浓度达到异常峰值提供强力的暖湿条件。过程Ⅱ,污染相对较轻,冷、暖平流交替出现,使污染物浓度呈波动式上升,增速慢,能见度存在日变化,下沉速度小,且雷达接收的气象回波信号弱。2次重污染过程都受外来污染物输送影响,但输送路径不同。

To study the mechanisms of heavy pollution weather,the evolutive characteristics of direct detection products and inversion products of wind profile radar were summarized from November 6 to 10,2015 and March 2 to 6,2019(ProcessⅠand ProcessⅡ,respectively)in Shenyang by using wind profile radar data,conventional meteorological observation data and atmospheric pollutant monitoring data.The results show that“ProcessⅠ”had stronger intensity,faster-increasing pollutant concentration,longer low visibility,greater subsidence rate,more stable dynamic conditions and stronger echo signal than that of“ProcessⅡ”.The stronger intensity and longer duration of warm advection in the lower layers provided warmer and wetter conditions for pollutant concentration to reach abnormal peaks in the“ProcessⅠ”.The two heavy pollution events showed that the external transport effect was obvious and the transport path was different.