Dear Prof. Jane Liu and all authors,

I had sent the revised manuscript to two referees for further review, but one of them did not give his/her review report until now. I think your manuscript can be accepted after the following issues have been addressed.

Figure 2b shows the 7-day backward trajectories (in meters above the ground) arriving at the TP surface. Since no trajectories are shown for the domain within the TP, it is difficult to see the transport pathways of air masses arriving at a specific region, e.g., the central TP. Air masses from the west (blue dots) are still at high altitudes (above 1000 m) at the western edge of the TP. Are 1-day backward trajectories for these air masses included in the plot? Will these air masses enter into the TP domain from the west or other side(s) of the TP? The authors may consider revising Fig. 2b and/or providing additional discussion for better understanding this subpanel.

While Fig. 2a presents low surface BC concentrations on the north of the TP, Fig. 2c shows high BC transported fluxes there. How about the regional distribution of BC column density? Or, does an elevated BC layer existing on the north of the TP?

Best regards, Jianzhong