Analysis on the Characters and Influencing Factors of a12 d Heavy Haze Pollution Weather Process
From 14 to 25 December 2013, a heavy haze pollution process occurred in the central and southern part of Hebei. By analyzing the meteorological conditions, flow field and characteristics of pollutants, the causes of this process are discussed. This pollution process which was closely related to haze presented such features as long duration, wide range and great intensity. With largescale stagnant meteorological condition and nearsurface atmospheric stratification, pollutants accumulated rapidly in the convergence zone of surface wind, leading to the formation of this heavy pollution process. There were two weak cold air activities during this period, but they were too weak to change the stagnant atmospheric stratification. Thus, the heavy pollution process, this time lasted a long time.