Response of the wintertime PM_2.5 level to anthropogenic emission mitigations in the Guanzhong basin

Based on the analysis of four typical unfavorable synoptic situations during wintertime in the Guanzhong basin (GZB), the WRF-Chem model had been applied to simulate the selected four days representing the four unfavorable synoptic situations during the wintertime of 2013. The results generally showed good consistence between the modeled and observed PM_2.5 distributions and variations. Further studies had been performed to verify the PM_2.5 response to the anthropogenic emission mitigation under the four unfavorable synoptic situations in GZB. Sensitivity results demonstrated that the mass concentration of PM_2.5 decreases nonlinearly along with the anthropogenic emission mitigation. Additionally, the PM_2.5 mitigation was more significant at the more polluted areas. The anthropogenic emission in GZB needed to be reduced 30%~60% to meet the China National Air Quality Standard under the above-mentioned four unfavorable synoptic situations.