Abstract:Based on conventional meteorological observation data and NCEP reanalysis data as well as hourly pollutant concentration data, seasonal characteristics of consecutive haze events in Xuzhou in 2013 are analyzed, including circulation background, surface meteorological characteristics, pollution forming and maintaining mechanism. The findings are as follows. Consecutive haze events are prone to occur when the cold advection at high level, warm high ridge at low level, and back of surface high or saddle pattern occur in autumn and winter, and southwest wind at high and low level, south airflow in the back of high pressure and the surface wind are not very weak in spring and summer. Wind speed in autumn and winter is very slow at night, slightly increasing during the day, but in spring and summer wind speed is stable relatively, being 2-3 m·s-1. Wind direction is northerly and easterly mainly in autumn and winter, but easterly to southeasterly in spring and summer. Temperature stratifications are stable with obvious surface layer thermal inversion during the consecutive haze events in autumn and winter. In contrast, inversion layers are higher in spring than in autumn and the summer stratification is unstable without obvious inversion. Shallow upward motion exists at low level， and downdraft at the upper level in winter and summer while it is downdraft in most cases during the spring and autumn nights.