General Comments

This study aims to investigate the reliability of the Offset Center of Gravity (OCOG) and University College London Land-Ice elevation (ULI) retracking algorithms through the analysis of, and comparison with, Level 1B waveform-derived Leading-Edge Width. Definitely, the study looks quite interesting and fits the interests of The Cryosphere. The manuscript is well written and logically organized. However, it lacks detailed descriptions of many important aspects (e.g., introduction and methodology). Therefore, I would suggest a major revision (see details below).

• The introduction needs to be improved. It makes sense to supplement the rationale of performing this kind of research.
• Have you tried Baseline-E for the LeW and I wonder if there is any difference between the two datasets?
• Figure 2: could you please also mark the boundary of the dry snow zone and percolation zone to make it easier for the readers to cross-reference the area in the manuscript?
• The methodology is oversimplified without providing technical details. For example, how do you filter the invalid waveforms and how to derive the time series? I suggest the authors add a flowchart of the developed approach in methodology.
• Line 60: Because CryoSat-2 also has SIN mode over Greenland, it would be better to clarify that you are focusing on LRM mode in the beginning. As far as I know, OCOG and UCL retrackers are applied to the LRM mode only as per the handbook of Baseline-D.
• Line 67: Please correct the citation format for (Ferraro & Swift, 1995), (Tourian et al., 2012) because a comma here looks weird.
• Line 134: Please provide some introduction to the Bayesian Estimator for Abrupt Seasonality and Trend (BEAST) algorithm. Why do you choose 1/8 year interval? I wonder what is the sensitivity to the interval (e.g., 1/4 or 1/2 year).
• I wonder if plotting the LeW as a result of the slope (e.g., from an Arctic dem) or roughness would help explain your finding.
• Figures 4 and 5: In addition to the time series, could you please also make a climatology plot that shows how the LeW varies for each of the months using all the data during 2010-2022?
• Line 260: I am interested to see a plot that includes the waveforms with retracked points marked before/after melt (would be good to mark the corresponding locations as well) and you could just select some typical waveforms to better illustrate how the LeW has varies due to the melt.

This study has the aim of determining the impact of different ice sheet melt regimes on satellite radar waveforms and elevation retrievals using data from the CryoSat-2 mission.

General Comments:

The introduction of the paper needs to be extended to provide more background, justification, and aim of the study. Explain why these biases are important and what new insights this study will provide to the community.

There is no clear justification for why only LeW is used in this study; this should be expanded upon in both the background section and the introduction. Also consider merging the "background" and "introduction" sections to provide a consistent narrative for your study.

I’m unclear about the main research question? Is the study focused on biases or on the sensitivity of retrackers to surface melt? If it is the latter, this has already been extensively proven in other studies, raising questions about the novelty of this research.

There is no explanation of how the different geographical areas were chosen; this should be included in the introduction or background of the manuscript.

The methods section is too vague and lacks detail, even for a short paper. There is no real description of the different steps or the reasons behind them.

The discussion mentions ICESat-2 and laser altimetry data, but it has not been included in the methodology and is presented to the reader in an ad-hoc manner. Add more details about the data and include figures to show the differences, as it seems analyses have been done to obtain these results.

The conclusion provides more information about the scope of the study than the introduction. More effort is needed to clearly define the research question and scope of the paper in the introduction to make the research question clear.

Detailed Comments

L115: Are you applying a mathematical surface to all data within the 125.6 km² area? Also, I would actually add the dimensions here, such as 10 x 10 km.

L133: Why was the “Bayesian Estimator for Abrupt Seasonality and Trend (BEAST) algorithm” used? It’s an interesting algorithm, but one can clearly see the impacts in the time series of surface melt, so I'm not sure of the need for it. However, I do think further background needs to be added to better understand the algorithm and its use. Additionally, why is the trend analysis included at all? There are no details explaining its inclusion or necessity.

L140: I don’t really understand this paragraph. I think it needs to be expanded.

L214: Laser altimetry has not been mentioned before. Is this something that has been investigated in the paper or is it coming from a reference? Is it airborne or space-borne laser altimetry? More details are needed.

L242: The possibility of another melt event can be easily checked using melt data from NSIDC or other sources, so I suggest that this is done or the sentence be removed.

L258: "CryoSAT-2" is misspelled.

L265: From this study, it is clear that the OCOG-retracker should be used as it is closer to the surface and thus less affected by changes in scattering. I think this should be added in the conclusion as a recommendation to use OCOG/Threshold retrackers over model-based retracking algorithms.