Brief communication: Sensitivity analysis of peak water to ice thickness and temperature: A case study in the Western Kunlun Mountains of the Tibetan Plateau

Gimenes, Lucille; Millan, Romain; Champollion, Nicolas; Bolibar, Jordi

doi:10.5194/tc-20-171-2026

Articles | Volume 20, issue 1

https://doi.org/10.5194/tc-20-171-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/tc-20-171-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 20, issue 1

Brief communication

|

13 Jan 2026

Brief communication |

| 13 Jan 2026

Brief communication: Sensitivity analysis of peak water to ice thickness and temperature: A case study in the Western Kunlun Mountains of the Tibetan Plateau

Lucille Gimenes, Romain Millan, Nicolas Champollion, and Jordi Bolibar

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Final revised paper (published on 13 Jan 2026)
Supplement to the final revised paper
Preprint (discussion started on 26 Aug 2025)
Supplement to the preprint

Interactive discussion

Status: closed

RC1:
'Comment on egusphere-2025-3460', Anonymous Referee #1, 08 Sep 2025

See attachment.

Citation: https://doi.org/10.5194/egusphere-2025-3460-RC1
- RC3:
  'Reply on RC1', Anonymous Referee #3, 06 Oct 2025
  
  See attachment.
  
  Citation: https://doi.org/10.5194/egusphere-2025-3460-RC3
  - AC4: 'Reply on RC3', Romain Millan, 10 Nov 2025
    
    See responses to general comment from RC3.
    
    Citation: https://doi.org/10.5194/egusphere-2025-3460-AC4
- AC1: 'Reply on RC1', Romain Millan, 03 Nov 2025
  
  See attachment.
  
  Citation: https://doi.org/10.5194/egusphere-2025-3460-AC1
RC2:
'Comment on egusphere-2025-3460', Anonymous Referee #2, 12 Sep 2025

please see attachment

Citation: https://doi.org/10.5194/egusphere-2025-3460-RC2
- AC2: 'Reply on RC2', Romain Millan, 03 Nov 2025
  
  See attachment.
  
  Citation: https://doi.org/10.5194/egusphere-2025-3460-AC2
RC4:
'Comment on egusphere-2025-3460', Anonymous Referee #3, 06 Oct 2025

See attachment

Citation: https://doi.org/10.5194/egusphere-2025-3460-RC4
- AC3: 'Reply on RC4', Romain Millan, 03 Nov 2025
  
  See attachment.
  
  Citation: https://doi.org/10.5194/egusphere-2025-3460-AC3

Peer review completion

AR – Author's response | RR – Referee report | ED – Editor decision | EF – Editorial file upload

ED: Reconsider after major revisions (further review by editor and referees) (10 Nov 2025) by Ben Marzeion

AR by Romain Millan on behalf of the Authors (13 Nov 2025) Author's response Author's tracked changes Manuscript

ED: Referee Nomination & Report Request started (15 Nov 2025) by Ben Marzeion

RR by Anonymous Referee #2 (26 Nov 2025)

Suggestions for revision or reasons for rejection

"Sensitivity analysis of peak water to ice thickness and temperature: A case study in the Western Kunlun Mountains of the Tibetan plateau" (revised version)
Review
Thanks to the authors for addressing my previous comments. The revised manuscript presents a much-improved introduction and now follows the standard OGGM framework (W5E5, dynamical spin-up, and calibration using glacier-specific observations). The future analysis is also strengthened with an ensemble of GCMs. I am happy with the new version and have only a few final comments that should be addressed before publication.
• In Figure S1, there appears to be a substantial shift (around 100%) in the snow+ice melt component around the year 2020, likely corresponding to the first year of the future simulations. This could indicate a potential issue in how the projections are applied or in the calculation of this component (which I assume should be computed over the same reference area as in the historical run). I encourage the authors to double-check this, as the issue is not visible in Figure 3, perhaps due to some smoothing applied to the glacier runoff.
• Based on the description in Section 2.5, the study does not appear to “propose a methodology to assimilate ice thickness inversions into the OGGM model,” as stated in the Introduction. Instead, the approach simply recalibrates the creep parameter A to match a different ice volume (MIL22 in this case). I recommend moderating this sentence.
Introduction
• “consquently” → “consequently”
• It seems Hock et al. 2019a and 2019b refer to the same reference.
• Consider the use of en dashes for number ranges.
Data and methods
• Define RCP at its first mention.
• “excepted for Fürst et al.” → “except for Fürst et al.”
• “a new global ice velocity product, that provides…” → “…product which provides…”
• “is approximately dated to 2000” → “corresponds approximately to the year 2000.”
• “differences after correction for glacier mass change average 6 km³” → “After correction, differences in glacier mass change average about 6 km³.”
• “ice thickness is in general, systematically higher…” → “In general, ice thickness is systematically higher…”
• Please indicate the exact OGGM version used in Section 2.3.
• “Dynamic spin-up that can provide glacier initial state for the year 2020” → This should likely refer to the year 2000 (or the RGI inventory year).
• “…can provide glacier initial state…” → “…can provide the glacier’s initial state…”
• “W5E5 is used by OGGM as standard baseline climate for dynamical spin-up or historical runs on the 1979–2019 time period” → “W5E5 is used by OGGM as the standard baseline climate for the period 1979–2019…”
• “hence we do not explore spatial and 2D differences” → “hence we do not explore spatial differences” (2D is redundant).
• Regarding 0.3% ± 4.5%, how was the 4.5% calculated?
• “which remains constant for several years or decades” → “which can remain constant for several years or even decades.”
Results
• “The forcing pathways start to notably differ around 2040 for mean temperature and precipitation.” → “The forcing pathways begin to diverge notably around 2040…”
• “23st century” → “23rd century”
• Please double-check the precipitation units, as 0.12 mm/day corresponds to roughly 40 mm per year, which seems unrealistically low for this region.
• Please use relative changes for precipitation (in some cases, changes exceed 50%).
• “Precipitation declines and then keeps roughly constant from 2165 a bit below 0.1 mm/d in SSP1-2.6” → This behavior is not shown in the figure.
• There is an unusual increase in year-to-year glacier area variability for SSP5-3.4 around the year 2160. This could indicate an issue with one of the GCMs.

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RR by Anonymous Referee #3 (28 Nov 2025)

Suggestions for revision or reasons for rejection

The authors have addressed most of my previous comments, and overall I believe this study is a valuable contribution to glacier model sensitivity to input datasets and temperature bias. For this reason, I can recommend publication after the following minor revisions/clarifications:

Lines 1, 25, 41, etc.: The manuscript switches between “western Kunlun”, “Western Kunlun”, and “West Kunlun”. I recommend choosing one form and using it consistently throughout.
Line 2: It is not entirely clear at this stage whether the temperature bias refers to the calibrated parameter. Is this value applied over the entire period (including the historical period)? If so, one would expect this to strongly influence the precipitation correction factor and, consequently, the runoff, but this is not described in the paper.
Lines 10–11: More recent numbers from the Glambie Team (2025) are available and could be cited here. I thought the contribution is closer to 1 mm per year now.

Line 19: The phrase “the latter depending” does not fully capture the message. I suggest: “and especially the ice thickness estimates”.

Line 34: The phrase “a region with strong variability between existing datasets” is repeated information and could be removed. Then, the Western Kunlun Mountains should be integrated into this sentence.

Line 65: Should this be “10% of the glaciers”?

Line 71: Remove “will”.

Line 73: Consider: “using a combination of up to five …”.

Lines 86–88: This sentence is unclear. Was velocity data available for fewer than 10 glaciers in the entire RGI region according to Millan et al. (2022)?
Line 116: “Fixed glacier area” may be misleading. Perhaps “fixed initial glacier area”? As written, it could be interpreted as if the glacier area does not evolve, whereas it is the domain over which runoff is computed that is fixed.
Lines 117–118: Remove “now”.
Line 142: Note that the ice thickness is not directly observed but derived through inversion or modelling. This should be described more accurately.
Line 156: Typically, an 11-year window is used, with the central year defined as the average of five years before and after. How is this implemented with a 10-year window?

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ED: Publish subject to minor revisions (review by editor) (28 Nov 2025) by Ben Marzeion

AR by Romain Millan on behalf of the Authors (06 Dec 2025) Author's response Author's tracked changes Manuscript

ED: Publish as is (08 Dec 2025) by Ben Marzeion

AR by Romain Millan on behalf of the Authors (16 Dec 2025) Author's response Manuscript

Short summary

This study looks how changes in glacier thickness estimates and temperature will affect the timing when meltwater from glaciers in the western Kunlun Mountains will reach its peak. Using a global glacier model and two different datasets, we found that thinner glaciers and warmer temperatures cause peak meltwater to happen sooner. This is of interests since it affects future water supplies for people relying on glacier runoff, highlighting the need for accurate ice volume estimates.