Research on Meteorological Features of PBL during Heavy Haze Episodes in the City of Chengdu, Sichuan Basin, China

Abstract:

Sichuan basin is one of the areas that have the most serious haze in China. To understand how wind, temperature ,relative humidity and PHLH influence air pollution, WRF was used to simulate the meteorological condition of PBL during two heavy haze episodes in 2013. Combined with the local meteorological data and air pollution data, the analysis shows that cyclone is caused by the terrain of basin often. Air pollutants are limited in the basin and accumulate periodically. The concentration of O₃ is significantly correlated with temperature while negatively correlated with relative humidity. There are significant negative correlations between the pollutants concentrations and the height of PBL. During the episode from 2^nd to 23^th March，the highest daily concentration of PM_2.5 was 270ug/m³. The relativity between PM_2.5 and O₃ is lower than normal because of the dust storm. The correlation coefficients between O₃ and temperature and relative humidity are 0.756 and -0.735, respectively. The dominant wind direction is south-west through the PBL. During the episode from 10^th to 22^nd April, the highest daily concentration of PM_2.5 was 158ug/m³. The correlation coefficients between O₃ and PM_2.5, temperature, and relative humidity are 0.516, 0.825, -797, respectively. The dominant wind direction was south-west through PBL.