2000− 2020 年 MERRA-2 和 TAP 大气黑碳数据在我国的精度分析和适用性评估

Black carbon (BC) is an important component of fine particles, posing risks to both atmosphere and human health because of its special physical and chemical properties. A comprehensive atmospheric black carbon concentration ground observation network has not been established in China, and the precise verification and applicability evaluation of regional BC concentration products remain limited. This study extracted 1616 BC observation data from 126 ground observation stations in China between 2000 and 2020 based on published literature, and conducted a thorough accuracy verification and applicability evaluation of BC data from MERRA-2 and TAP datasets. The results showed that: (1) Both the MERRA-2 and TAP datasets underestimated the atmospheric BC concentration in China, with MERRA-2 underestimating by 8.13% and TAP underestimating by 19.51%. The correlation between TAP BC concentrations and the observation data (R=0.62, FAC2 (fraction of predictions within a factor of two of observations)=0.69) was higher than that of MERRA-2 (R=0.46, FAC2=0.58), while the 20 years average value of MERRA-2 (3.61 μg/m³) was closer to that of observed data (3.97 μg/m³). (2) There were significant differences in the accuracy of BC concentration between the two datasets across different regions in China. MERRA-2 performed better than TAP in the Southwest and North China. Both datasets showed high accuracy in the Southwest region (R ranging from 0.68 to 0.84, FAC2 from 0.71 to 0.79), whereas the accuracy in North China was relatively low (R ranging from 0.41 to 0.48, FAC2 between 0.64 to 0.77). (3) MERRA-2 and TAP were significantly positively correlated in most regions of China. Sichuan Province had the smallest difference in BC concentration (0.0045 μg/m³), and the largest difference was in Beijing (2.11 μg/m³). MERRA-2 has a longer time span, while TAP can more accurately represent the spatial distribution of BC concentration, and the two show large differences in different regions.