The relationship between black carbon and atmospheric boundary layerheight

Özet

Black carbon (BC) has a significant influence on regional climate and human health. Variations of BC aerosol andatmospheric boundary layer height (BLH) were investigated in an urban site over Wuhan from November 2014to November 2016. The annual average BC concentration and BLH were approximately 3.01 ± 1.97μg/m3and892 ± 389 m, respectively. The variation of BC is opposite to that of BLH. The maximum monthly mean BC was4.32 ± 2.3μg/m3in December, and the minimum monthly mean BC was 1.94 ± 1.9μg/m3in July. Themaximum monthly mean BLH was approximately 1211 ± 308 m in July, and the minimum monthly mean BLHwas approximately 668 ± 342 m in January. Moreover, the high BC mass concentration days have relativelyhigher relative humidity (RH) values than the clean days, and the high RH values were usually accompanied bylow BLH. The relationship between the BC concentrations and BLH exhibits a negative correlation. The corre-lation coefficient was R2= 0.424 on the polluted days, whereas the R2coefficient was approximately 0.0037during the clean periods. The PM2.5and BLH have no evident relationship in low (R2= 0.0097) or high(R2= 0.058) BC concentrations. Results indicate that the BC mass concentration would suppress the BLH on thepolluted days. The increased BC aerosol concentration resulted in lower BLH and led to poor air quality