Reply to comments from Reviewer 1

the capability of backscatter retrieval using snow microstructure measurements as inputs in a radiative transfer model, SRTM. The paper presents a viable case for a dedicated spaceborne snow mission and explains how the backscatter measurements can be used to characterize snowpack properties. The paper combines methodologies used in previous studies for classification and optimization with novel snowpack measurement techniques to estimate background 5 and snow volumetric backscatter. The paper is well thought out and constructed

General comments I understand the authors' point that given the scale of this database is rather difficult to map all the locations described in Figure 1 and the reader is referred to the original publications for additional site information. However, since the main component of the manuscript is the detailed description of each site, I think it would be very useful to include, close up maps for all these locations. For example, one suggestion would be to consider including the photos from figures 5 and 7 in one single figure which also includes a map indicating the location of this site and the ones nearby. Similar recommendation for Figures 7 and 8.
Response: We agree this is a good idea. In the revised manuscript, we add 6 regional maps to show locations where LIG sites are clustered. In these maps we also label local geographic features that are mentioned in the text to better situate the reader.

elevation…"
Response: We agree this is redundant, but we keep these as separate sections because they are separate entries in the database. We aim to make each site description a "stand-alone" piece of text in this manuscript.
Section 6.10, to avoid repeating "(marine sand, and clays (constrained to MIS 5e; LIG) are located between …), maybe use instead something like: "marine sand, and clays (constrained to MIS 5e; LIG) are located …" and then list the 4 sites.
Response: A noted above, we agree this is somewhat redundant, but we use this notation because these are separate sites in the database. Moreover, some of the details (eg. Elevation of marine sediments and age constraints) are different at these sites. Therefore, it would be difficult to merge this into a single site description. We aim to make each site description a "stand-alone" piece of text in this manuscript.
Section 6.15, I suggest deleting "site" from the first 2 subsections titles. It seems that at each site description there is the same sentence that: "A LIG-age is also suggested by correlation of pollen data from this site with the climate for western Europe (Zagwijn, 1996). To avoid repeating this, the authors could mention this once at the beginning of the section and to mention that this applies to all sites in 6.15.
Response: As suggested, we removed "site" from the two sub-section titles. Regarding the pollen data: we agree the same references are used in most subsections. However, the age inferred from pollen data is different throughout the 11 sections described here. For example, pollen data suggest a broad age assignment of 133-119.5 ka for the Zaton site, and pollen data offer a more constricted age assignment for the Bychye site (133-124 ka). We therefore find it appropriate to cite the pollen studies and provide additional site-specific context in each subsection.
Section 6.26, I do not see it necessary to create subsections, but instead I suggest list the 3 boreholes. This way, the word "borehole" is not repeated as often as it is now.
Response: As part of the standard formatting used in this manuscript, we created a separate subsection for each site where LIG marine sediments were located. We feel this format is best suited for the reader who is interested in knowing the location of individual occurrences of the LIG marine sediments. Therefore, in this section, we describe 3 separate boreholes.
To avoid confusion, I recommend to clarify the difference between "a date" and "an age" and use it correspondingly throughout the manuscript. I also suggest merging the subsections 4.1.5.-4.1.7. into Luminescence dating methods.
Response: We use the 'date' and 'age' notation interchangeably, depending on the context of the site. We broke down "Luminescence dating methods" into 3 separate subsections to reflect 3 very different dating methods and to permit discussion of the pros/cons and key characteristics associated with each.
For consistency throughout the manuscript, please consider the following: Use properly "sea-level" and "sea level" Response: Thank you to the Reviewer for pointing this out. We have made several corrections of this in the revised manuscript, including the title.
Choose one of U-Th, U/Th, 230Th, uranium/thorium, 230Th/234U when you refer in the text to the U-series age. Same for radiocarbon dating vs 14C .
Response: In the revised manuscript, we adopt the "U/Th" notation. We also refer to "radiocarbon" thorough the revised manuscript, except for section 4.1.2 where we use "14C" in cases where we specifically refer to the decay of the 14C isotope.
Once it has been clarified in the text that the Eemian is LIG in western, central and northern Europe, there is no need to repeat it later in the manuscript.
Response: We agree with this suggestion. In the revised manuscript, we define the LIG in the Introduction (equivalent to MIS 5e; Eemian…etc) and then we refer only to "LIG" afterward. We further remove "MIS5e" from the title and instead state "Last interglacial".
Perhaps you could mention once in the description of the relative sea level proxies that: "The geochronological results are reported for all the sites where data is available." and no need to mention at each site where there are no ages that "No geochronological data are available for x site." Response: We update the manuscript accordingly.
1298: suggest rephrasing this sentence: "Radiocarbon ages ….yielded ages" Response: We update the manuscript accordingly.      Response: We make this change to the citation style in the revised manuscript. Figure 8: replace "forests" with "foresets" Response: Thank you AR1 for your careful review of our manuscript. We made this change to the revised version. Table 5. Replace "nation" with "country".

Figures and tables
Response: We make this change in the revised manuscript.