Publisher’s note: a supplement was added to this comment on 13 June 2024.

The review will be sent in a separate file.

This paper describes 11 years of lidar data at 30N in eastern China and compares the measurements to several satellite and other lidar records. The period includes several volcano and wild fire events.

The primary difficulty with the paper is in the variable altitude intervals used in the sAOD comparisons. First it is not clear why the Wuhan data above 25 km are not used for the sAOD calculation, while all other sites extend their sAOD calculations to 30 km or above. Second there is often a lot of stratosphere and aerosol below 17 km where the Wuhan calculations begin, particularly in the winter months, yet this region also seems to be ignored. Why is that when other record extend to the tropopause or 1 km above the tropopause? The impact of ignoring these differences on the sAOD comparisons is not even mentioned, yet it may contribute significantly to the differences which are observed.

Here are additional detailed comments to address.

Figure 1. The labels on some lidar sites may be misleading. Are both the Hampton and Sao Jose dos Campos sites still making measurements? If not then indicate the time frame of measurement availability.

166-167. The explanation for the source of the sulfur for the stratospheric aerosol layer isn’t correct. While tropospheric SO2 plays a, still unquantifiable role, H2S does not get to the stratosphere. The primary source of stratospheric sulfur is OCS. See any of the review papers on stratospheric aerosol e.g. Kremser et al., 2016 or the SPARC Assessment of  Stratospheric Aerosol Properties  (Thomason and Peter).

Fig. 3 and discussion on sAOD. The authors need to discuss and perhaps quantify the fraction of sAOD ignored during the winter by limiting their integration to 17-25 km. In the winter there is up to 4 to 5 km of the atmosphere ignored in this formulation as the tropopause descends in winter.

Table 2 suffers from similar problems. All the mid latitude lidars save Haute Provence calculate AOD by integrating from near the tropopause to > 30 km. The Mauna Loa lidar is integrated from 17 km, but this is a tropical site and the tropopause varies little from 17 km throughout the year. Without having similar altitude integrals it is unclear what the value is in comparing sAODs. Also the sAODs are not just one number. What is reported, the mean, median, is there a standard deviation, …?

Fig. 9 Is there a mistake in the abscissa label? Should it be Mm-1 sr-1 as in all the other plots? What does the shading represent? If the standard deviation then wouldn’t it be much larger? Notice in the previous plots the backscatter coefficient exceeds values of 1 Mm-1 sr-1 in  a number of cases.

Fig. 10 The altitude interval over which these calculations were made should be mentioned. The quantities in the box and whisker plots should be defined in the caption. What is the box, the center line, …?

359 …60 W/m2 for BC …

363 How are sAOD_OC and sAOD_BC determined from the lidar data?