京津冀雾霾消散因子及其阈值研究

A study on haze dissipation factors and their thresholds over Beijing-Tianjin-Hebei area

  • 摘要: 利用2006—2015年京津冀气象站的常规观测资料和同期NCEP/NCAR再分析资料,以秋冬季影响雾霾形成与消散的静稳大气和通透大气为研究对象,统计分析了气象因子的分布状况。结果表明:京津冀秋冬季降水对雾霾起不到冲刷作用,反而促进雾霾的形成与维持;京津冀秋冬季雾霾消散主要是风场因子的贡献。雾霾消散的大气状态可分为3种类型,在不同大气状态下,各风场因子对雾霾消散的贡献不同。采用迭代自组织数据类差最大值阈值分割法找出了各风场因子的最佳阈值。根据各风场因子对雾霾消散的敏感性和因子间的相关,筛选出3类大气状态下雾霾消散因子指标。采用指标叠套法对2016、2017年秋冬季大气进行检验,表明雾霾消散指标及其阈值能较好区分静稳大气和通透大气,对雾霾过程具有较好的指示意义;通过对derf2.0模式产品释用,可为延伸期雾霾过程客观化预测提供技术支撑。

     

    Abstract: Based on conventional observation data collected at weather stations over Beijing-Tianjin-Hebei area during 2006—2015 and daily reanalysis data of the NCEP/NCAR, several meteorological elements in stable atmosphere condition corresponding to haze formation and in transparent atmosphere condition corresponding to haze dissipation in the autumn and winter are statistically analyzed. The results show that precipitation in Beijing-Tianjin-Hebei area in the autumn and winter actually promotes the formation and maintenance of haze instead of washing it out. Haze dissipation over Beijing-Tianjin-Hebei area in the autumn and winter is mainly controlled by wind field factors. The atmospheric state for haze dissipation can be divided into three types. Under different atmospheric states, the contribution of each wind field factor to haze dissipation is different. The optimum threshold of wind field factor can be found by the "class difference maximum threshold segmentation method of iteration self-organizing data". According to the sensitivity of each wind field factors to haze dissipation and the correlation between the factors, the index factors of haze dissipation for the three types are found out. Using index iterative method, the atmospheric states in the autumn and winter of 2016 and 2017 are inspected. The results show that according to the haze dissipation index and its threshold value, the statically stable atmosphere and the transparent atmosphere can be well distinguished, which provides a good indication for the haze process. The interpretation and application of derf2.0 model products can provide technical support for objective prediction of haze process.

     

/

返回文章
返回