Abstract:

Based on NCEP/NCAR reanalysis data and MM5, characteristics of weather system during the most serious haze process in winter of 2010 were analyzed in the central cities of Liaoning province. Characteristics of haze weather and daily mean PM₁₀ concentrations in winter of 2010 in Shenyang, Liaoyang and Benxi were simulated by a CALPUFF model. The results indicate that it is weak warm ridge in Liaoning province at 500 hPa geopotential height field, while it is influenced by divergence and downdraft at 800 hPa geopotential height field. Surface wind directions are inconsistent, and they are affected by divergent flow. It has an obvious potential vorticity rising area above the ground and at low altitudes according to the vertical profile of wind field. It has significant inversion temperature at low altitude based on temperature profile from ground to upper level, and the top of inversion layer is lower. PM₁₀ concentrations on December 19 to 21, 2010 in Shenyang, Liaoyang, Benxi diffuse to east, northwest, southeast directions, which is influenced by surface wind direction. In the whole winter, it diffuses to south for mean PM₁₀ concentration.

Key words: Haze weather, Numerical simulation, Central city of Liaoning province