This manuscript investigated long-term variations of carbonaceous aerosols during 2010-2017 in Shanghai, based on field measurement of OC and EC by a semi-continuous carbon analyzer. Although it derived some patterns/findings from a large dataset, the scientific significance of this manuscript was rather fair (as a measurement report). I also have substantial concerns on the methodologies. 

• First, the estimation of SOC. (1) Biogenic OC, as a type of primary OC, should not be ignored for Shanghai. (2) The robustness of the (OC/EC)pri, i.e., the OC to EC ratio representative of primary combustion sources, must be carefully evaluated. As shown in Fig. S2-S9, (OC/EC)pri showed significant monthly variations, and the variation patterns appeared pretty different among various years. In addition, (OC/EC)pri frequently exhibited abrupt and significant variations between successive months (i.e., within a relative short period). This did not make sense.
• Second, annual variations of carbon concentrations, as a main focus of this manuscript, are indeed important. However, I think they are not enough for an ACP paper. For example, inter-annual variation of meteorological conditions could also influence the patterns observed for carbonaceous aerosols, but relevant discussions are limited (e.g., Figure 1a). 
• Third, this manuscript was quite similar to Wang et al. (Atmos. Chem. Phys., 22, 12789–12802, 2022), with respect to methodologies, data analysis approaches, etc., thus this paper was in lack of innovative viewpoints. Even if the authors think this problem is not critical, and the authors may consider this as the foundation of combining data from the two studies, but the sampling in Wang et al. (2022) is at a different site, so the equivalence of measurement results (e.g., OC and EC concentrations, and (OC/EC)pri) should be demonstrated first for the overlapping period. 
• In addition, I suggest clearly distinguishing OC (in ugC/m3) and OA (in ug/m3). Particularly, OA should be used when comparing to PM2.5 mass concentration (e.g., Figure 1b).