京津冀和长三角地区一次重霾过程气象成因及传输特征

基于气象数据和空气质量数据，研究了2016年12月29日~2017年1月8日京津冀与长三角地区一次大范围重度污染过程的特征及成因.结果表明，均压场、低边界层高度、静小风是本次重污染过程的主要气象特征，重污染过程的结束得益于后期气压梯度变大，水平扩散条件转好.此外，基于WRF-CMAQ（气象研究与预报建模系统及区域多尺度空气质量模型）模式情景分析法评价了区域传输和局地累积对本次重污染过程的作用，分析显示重污染前期当中东部地区受南风控制时，京津冀地区受长三角地区传输影响较大（15%~20%），长三角地区以本地贡献为主；累积阶段，长三角地区本地贡献显著下降，受到京津冀地区的贡献明显上升（20%~30%），京津冀地区主要受本地排放影响.传输通量结果显示长三角向京津冀输送的净通量峰值发生在重污染前期（-21.52t/d），京津冀向长三角输送的净通量峰值发生在累积阶段（17.29t/d），区域传输作用在1001~1478m之间最为活跃.

Analysis of meteorological causes and transmission characteristics of a heavy haze process in Beijing Tianjin Hebei and Yangtze River Delta

Based on meteorological data and air quality data, the characteristics and causes of a large-scale severe pollution process in Beijing Tianjin Hebei region and Yangtze River Delta region from December 29, 2016 to January 8, 2017 were analyzed. The main meteorological characteristics of the heavy pollution process were pressure field, low boundary layer height and quiet breeze. The end of the heavy pollution process was due to the higher pressure gradient and better horizontal diffusion conditions, Based on the WRF-CMAQ (Weather Research and Forecasting Model and Community Multi-scale Air Quality) scenario analysis method, the effects of regional transmission and local accumulation on the heavy pollution process were evaluated. The analysis showed that in the early stage of heavy pollution controlled by south wind, the Yangtze River Delta region was mainly affected by transmission (15% ~ 20%) from the Yangtze River Delta, and the Yangtze River Delta region was mainly influenced by local contribution; in the accumulation stage, the local contribution of the Yangtze River Delta region decreased significantly, while the contribution from Beijing Tianjin Hebei region increased significantly (20% ~ 30%).The results showed that the peak value of the net transmission fluxes fromYangtze River Delta to Beijing Tianjin Hebei region occured in the early stage of heavy pollution (-21.52t/d), and the peak value of net transmission fluxes from Beijing Tianjin Hebei region to Yangtze River Delta occured in the accumulation stage (17.29t/d), the regional transport effect was the most active between 1001 and 1478m.