Abstract. In this study, we investigated the characteristics of and changes in the sources of carbonaceous aerosols in northern Chinese cities after the implementation of the Action Plan for Air Pollution Prevention and Control in 2013. We collected PM2.5 samples from three representative inland cities, viz. Beijing (BJ), Xi’an (XA), and Linfen (LF) from January 2018 to April 2019. Elemental carbon (EC), organic carbon (OC), levoglucosan, stable carbon, and radiocarbon were measured in PM2.5 to quantify the sources of carbonaceous aerosol employing Latin hypercube sampling. The best estimate of source apportionment showed that the emissions from liquid fossil fuels contributed 33.6 ± 12.9 %, 26.6 ± 16.4 %, and 24.6 ± 13.4 % of the total carbon (TC) in BJ, XA, and LF, whereas coal combustion contributed 11.2 ± 9.1 %, 19.2 ± 12.3 %, and 39.2 ± 20.5 %, respectively. Non-fossil sources accounted for 55 ± 11 %, 54 ± 10 %, and 36 ± 14 % of the TC in BJ, XA, and LF, respectively. In XA, 48.34 ± 32.01 % of non-fossil sources was attributed to biomass burning. The highest contributors to OC in LF and XA were fossil sources (65.4 ± 14.9 % and 44.9 ± 9.5 %, respectively), whereas that in BJ was non-fossil sources in BJ (56.1 ± 16.7 %). The main contributors to EC were fossil sources, accounting for 92.9 ± 6.13 %, 69.9 ± 20.9 %, and 90.8 ± 9.9 % of the total EC in BJ, XA, and LF, respectively. The decline (6–17 %) in fossil source contributions in BJ and XA since the implementation of the Action Plan indicates the effectiveness of air quality management. We suggest that measures targeted to each city should be strengthened in the future.
Supplementary material to "Measurement report: Source apportionment of carbonaceous aerosol using dual-carbon isotopes (<sup>13</sup>C and <sup>14</sup>C) and levoglucosan in three northern Chinese cities during 2018–2019"
