The manuscript I reviewed is already a revised version. I like it very much. Not only is the research original, but the data products are unique and significant for various stakeholders. To my knowledge no one has published similar datasets in the literature. It's a pleasant read and I also learned from this reading. I have only a few editorial comments, which can be made during galley proof corrections. 

Fig. 1. Need to explain (a) in the caption. Also explain the meaning of “frequency of surface water occurrence” and the cross symbols in each panel.

Fig. 2 caption: Please add one sentence similar to this: “The details of individual steps and the meaning of the symbols are described below.”

Figs. 3 and 13. Change “Measure Salinity (ppt)” to “Measured Salinity (ppt)” in all x-axis labels.

Fig. 6. I like this figure as it makes visual inspection straightforward. The lower salinity around the land-lake boundaries may be due to runoff, but what caused the high salinity points (reddish colors) in c7?

Fig. 11. Put some space between column 3 and column 4, and between column 6 and column 7.

Eq. (8) – what’s the unit of g? Need to list.

The study fully leverages the physical mechanisms underlying passive remote sensing of water salinity and the high spatial resolution advantages of optical remote sensing, enabling salinity estimation for inland lakes across China. The lake salinity dataset provided by the research is highly valuable for monitoring biogeochemical processes within lake ecosystems. The manuscript is clearly structured, but a few minor issues still require revision. It could be considered for publication after these revisions are made. These small issues are as follows:

1. Line 90: The citation order of the figures jumps from Fig. 1 directly to Fig. 10. You may need to move Fig. 10 to the position of Fig. 2, or remove the citation of Figure 10 at this point.
2. Please move the word “Catchment” in Table 1 onto a single line to ensure the integrity of the term.
3. The section number 2.5 seems it should be changed to 2.6.
4. In the caption of Figure 3, please remove the comma ‘,’ after “RMSE = 0.82 ppt”.
5. Line 443: Should the square brackets be changed to parentheses?

This study provides new insights into efficient monitoring of lake salinity for smaller lakes, due to improved spatial resolution achieved through the use of microwave and optical imagery. The presented methodology and accompanying data are of great value in environmental monitoring. The methods are described very clearly. The interpretation of the results and the visual representation are of high quality. Overall, I consider this paper acceptable as it is, as I have read the already revised version and the comments of other referees.