I wholeheartedly agree with the two referees that this study is a very valuable contribution to the scientific community’s efforts to piece together the puzzle of how to combine multi-source remote sensing data to determine the depths and volumes of supraglacial lakes on the ice sheets with greater accuracy. This would allow researchers to better understand and model surface hydrological processes on the ice sheets and therefore has the potential to improve future projections of ice sheet mass balance and sea level rise. In particular, the in-situ sonar data presented in this study finally provides the community with much-needed calibration or validation data that overlaps with recent satellite observations. After a few relatively minor modifications, as suggested by the two referees, I would love to see this manuscript getting published in The Cryosphere.

I have one particular suggestion, which I believe would make the science presented in this study more open and accessible while also increasing its impact. I strongly encourage the authors to publish the underlying data (and ideally the code) to a publicly accessible repository that creates a permanent and citable DOI (such as Zenodo). To the best of my knowledge*, the sonar data is the only in-situ depth data of supraglacial lakes that overlaps with the Landsat 8 and Sentinel-2 missions. As such, it would be incredibly useful for the research community to have easy and free access to this data, and I would imagine that the authors of a number of future studies would use the data to motivate their own research or to validate their results.

I also believe that including a reference to Melling et al. (2024) would be very appropriate and useful to readers. 

* Based on the following list of (non-single point) in-situ observations of supraglacial lake depth on the ice sheets. (Let me and the community know if you are aware of any that I am missing!)

• Box and Ski (2007): two lakes in Central West Greenland in Aug 2005
• Tedesco and Steiner (2011): one lake in West Greenland in July 2010
• Sneed and Hamilton (2011): one lake on Helheim Glacier in July 2008
• Legleiter et al. (2014): three supraglacial water bodies in West Greenland in July 2012

References:

Box, J. E., & Ski, K. (2007). Remote sounding of Greenland supraglacial melt lakes: implications for subglacial hydraulics. Journal of glaciology, 53(181), 257-265.

Legleiter, C. J., Tedesco, M., Smith, L. C., Behar, A. E., & Overstreet, B. T. (2014). Mapping the bathymetry of supraglacial lakes and streams on the Greenland ice sheet using field measurements and high-resolution satellite images. The Cryosphere, 8(1), 215-228.

Melling, L., Leeson, A., McMillan, M., Maddalena, J., Bowling, J., Glen, E., Sandberg Sørensen, L., Winstrup, M., and Lørup Arildsen, R.: Evaluation of satellite methods for estimating supraglacial lake depth in southwest Greenland, The Cryosphere, 18, 543–558, https://doi.org/10.5194/tc-18-543-2024, 2024.

Sneed, W. A., & Hamilton, G. S. (2011). Validation of a method for determining the depth of glacial melt ponds using satellite imagery. Annals of Glaciology, 52(59), 15-22.

Tedesco, M., & Steiner, N. (2011). In-situ multispectral and bathymetric measurements over a supraglacial lake in western Greenland using a remotely controlled watercraft. The Cryosphere, 5(2), 445-452.