the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
| 15 Sep 2026
ThawCoupler-1D (v1.0): A physically-based one-dimensional coupled thermo-mechanical model for simulating thaw subsidence in heterogeneous permafrost
Abstract. Permafrost thaw subsidence threatens infrastructure across Arctic and high-altitude regions and alters local hydrology. However, predicting the magnitude and rate of this deformation remains difficult due to the complex mechanical behavior of heterogeneous ground ice. Existing land surface models (LSMs) typically represent subsidence as a simplified geometric volume loss, omitting the transient dissipation of pore water pressure. Conversely, highly detailed geotechnical models are computationally expensive, making them impractical for multi-decadal, climate-scale simulations. To resolve these limitations, we developed ThawCoupler-1D (v1.0), a physically-based, computationally efficient finite-difference model designed to simulate thaw subsidence across highly variable ground-ice conditions. The model implements a threshold-based algorithm that switches between two settlement modes based on the initial void ratio: (1) large-strain thaw consolidation for porous soil matrices, governed by coupled heat transfer and pore water pressure dissipation; and (2) volumetric collapse for massive ice bodies (e.g., ice wedges), governed by phase-change kinetics and structural failure. The model utilizes a vectorized numerical scheme with an adaptive time-stepping algorithm constrained by the Courant-Friedrichs-Lewy (CFL) condition, allowing stable multi-decadal simulations at sub-daily and millimeter-level resolutions. We verified the model against analytical benchmarks and evaluated its performance using in situ borehole observations from the Beiluhe basin on the Qinghai-Tibet Plateau. The results show that ThawCoupler-1D reproduces the seasonal zero-curtain effect in thermal profiles and captures the non-linear settlement dynamics of both segregated and massive ground ice. Projections under CMIP6 scenarios indicate a critical thermal threshold, beyond which massive ice undergoes rapid volumetric collapse. This open-source code provides a tool for investigating thermo-mechanical feedbacks in degrading permafrost landscapes and improving sub-grid parameterizations in Earth System Models (ESMs).
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Status: open (until 10 Nov 2026)
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CEC1: 'Comment on egusphere-2026-3345 - No compliance with the policy of the journal', Juan Antonio Añel, 23 Sep 2026
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AC1: 'Reply on CEC1', Guoan Yin, 24 Sep 2026
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Dear Prof. Juan A. Añel,
Thank you very much for reviewing our manuscript and for bringing the "Code and Data Policy" compliance issues to our attention. We fully acknowledge and support the journal’s strict policy on open science, reproducibility, and long-term data provenance.
We have addressed all the raised issues by properly archiving both the model forcing and the evaluation datasets in an approved, long-term repository with persistent identifiers.
Specifically, we have completed the following actions:
Resolution of Meteorological Forcing Data Availability: Instead of referring to the general portal homepage, the exact, bias-corrected daily meteorological forcing dataset (1980-2100) used to drive all historical simulations and CMIP6 future projections in our study has now been directly included in the public repository, fully tagged with its own persistent identifier.
Public Release of In-situ Borehole and Soil Datasets:The previously restricted in-situ datasets from the Beiluhe Basin—including the continuous daily borehole temperature time series (at depths of 0.1 m, 2.5 m, and 5.0 m) records (2016–2025), and the stratigraphic physical parameters-have now been made fully accessible and publicly available without any restriction.
Repository Information and Persistent Identifier:All the code, input forcing datasets, field evaluation observations, and plotting routines required to replicate findings in the manuscript have been comprehensively consolidated and archived on Zenodo(https://doi.org/10.5281/zenodo.22939262).
When the Topical Editor requests a revised version of the manuscript, we will promptly update the "Code and data availability" section to formally cite the new repository and include the full bibliographic references in the References list as follows:
Code and data availability:
The source code of ThawCoupler-1D (v1.0) and all datasets required to replicate the simulations in this study (including the bias-corrected daily climate forcing from 1980 to 2100, borehole temperature time series, and soil stratigraphic parameters from the Beiluhe Basin) are publicly available on Zenodo at https://doi.org/10.5281/zenodo.22939262 (Yin, 2026).
Thank you once again for your constructive guidance and for maintaining the rigorous standards of GMD. We hope that these revisions fully resolve the compliance concerns, and we look forward to continuing with the peer-review process.
Sincerely,
Guoan Yin
On behalf of all co-authors
Citation: https://doi.org/10.5194/egusphere-2026-3345-AC1 -
CEC2: 'Reply on AC1', Juan Antonio Añel, 24 Sep 2026
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Dear authors,
Thanks for addressing this issue so quickly. I have checked the repositories and we can consider now the current version of your manuscript in compliance with the code policy of the journal.
Juan A. Añel
Geosci. Model Dev. Executive Editor
Citation: https://doi.org/10.5194/egusphere-2026-3345-CEC2 -
AC2: 'Reply on CEC2', Guoan Yin, 24 Sep 2026
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Dear Prof. Juan A. Añel,
Thank you very much for your time in checking the repositories and for confirming our manuscript's compliance with the GMD Code and Data Policy.
We truly appreciate your swift feedback and guidance in helping us uphold the open-science and reproducibility standards of the journal. We remain at your and the Topical Editor's disposal should any further information be required as the review process proceeds.
Sincerely,
Guoan Yin
On behalf of all co-authors
State Key Laboratory of Cryospheric Science and Frozen Soil Engineering,
Northwest Institute of Eco-Environment and Resources, Chinese Academy of SciencesCitation: https://doi.org/10.5194/egusphere-2026-3345-AC2
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AC2: 'Reply on CEC2', Guoan Yin, 24 Sep 2026
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CEC2: 'Reply on AC1', Juan Antonio Añel, 24 Sep 2026
reply
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AC1: 'Reply on CEC1', Guoan Yin, 24 Sep 2026
reply
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RC1: 'Comment on egusphere-2026-3345', Anonymous Referee #1, 28 Sep 2026
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Comments on “ThawCoupler-1D (v1.0): A physically-based one-dimensional coupled thermo-mechanical model for simulating thaw subsidence in heterogeneous permafrost”
This manuscript presents ThawCoupler-1D v1.0, a new one‑dimensional Lagrangian finite‑difference model coupling heat transfer and large strain thaw consolidation to simulate thaw subsidence in heterogeneous permafrost. The model introduces a threshold driven dual-mechanism scheme: it solves pore‑water‑pressure‑governed consolidation for segregated-ice soil layers and applies volumetric collapse logic for massive‑ice bodies such as ice wedges. The authors perform hierarchical analytical verification, validate against multi-year borehole observations from the Beiluhe basin on the Qinghai Tibet Plateau, and run CMIP6 SSP based future projections across three representative cryostratigraphic scenarios (ice poor alpine desert, ice rich alpine meadow, massive‑ice swamp meadow).
The manuscript is well-structured, the mathematical formulation is clearly documented. The study delivers important insights on densification-acceleration positive feedback and latent-heat buffered thermal tipping points in ice‑rich permafrost. This work fills a clear methodological gap between simplified land surface model geometric subsidence schemes and computationally expensive geotechnical finite-element models. Overall, the science is sound and fits well within the scope of Geoscientific Model Development. Nevertheless, several moderate clarifications, contextual comparisons, textual refinements and figure improvements are required before acceptance. I recommend Minor Revision.
- The void‑ratio threshold ethreshold=500defines the transition between thaw consolidation mode and volumetric collapse mode. The authors correctly note this is partly a numerical safeguard to avoid infinite consolidation coefficients for near pure ice. However, the physical meaning of this hard cutoff needs deeper discussion. Real world ground ice exists along a continuous spectrum between segregated ice and massive ice. Please clarify:
- How sensitive are modelled subsidence timings and magnitudes to small perturbations of this threshold value? Add one short sensitivity test summary either in main text or supplementary material.
- Explain whether partial massive ice fractions within one model layer can be represented under the current framework, or whether each grid cell must be assigned fully to one deformation mode. This is critical for users applying ThawCoupler-1D to real borehole stratigraphy with mixed ice types.
- Validation of the thermal module uses highquality in-situ borehole temperature records, yet continuous located measured subsidence time series are absent. The authors compare simulated subsidence magnitudes against regional InSAR and geomorphological surveys. While this indirect validation is reasonable given observational scarcity in remote high elevation permafrost terrain, please explicitly discuss potential non-uniqueness of model parameters. I suggest adding one paragraph discussing equifinality risk, and advise future users to constrain mechanical parameters from local laboratory or field consolidation tests wherever possible.
- The manuscript contrasts ThawCoupler-1D with classical landsurface models and geotechnical finite‑element models. Please strengthen explicit comparison against existing 1D permafrost models that treat excess ground ice, for example CryoGrid 3 excess-ice implementations. Highlight precisely what ThawCoupler-1D adds: namely the fully coupled pore water pressure driven large strain consolidation instead of purely geometric volume removal. Clarify which components could potentially be adapted as sub-grid parameterizations for Earth System Models (ESMs), and what barriers remain for direct coupling into CLM or CryoGrid family codes.
- In the abstract line 28 and conclusion point (4), state explicitly that adaptive timestepping is constrained by both thermal diffusion and pore pressure dissipation (dual criterion CFL condition), not only thermal CFL. This is a key numerical novelty of the vectorized solver.
- Figure 1 illustrates two deformation modes. Please add short labels indicating excess porewater pressure build up in panel (c) “Thaw consolidation mode”, so readers can visually link the schematic to equation 6 9 for consolidation. Also improve resolution of sub panel captions for preprint readability.
- In Table 1, define symbol mvclearly: coefficient of volume compressibility; add its SI unit annotation directly inside table header. In Table 2, for scenario C massive ice layer, hydraulic conductivity k is assigned zero. Add one short footnote explaining that k = 0 is a numerical setting for pure‑ice layers handled by volumetric collapse branch, and this layer bypasses the consolidation PDE solver.
- When describing biascorrection for AWI-CM-1-1-MR outputs, briefly state the rationale for selecting this particular global model for the Tibetan Plateau instead of alternative CMIP6 models. One short sentence is sufficient.
Citation: https://doi.org/10.5194/egusphere-2026-3345-RC1
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Dear authors,
Unfortunately, after checking your manuscript, it has come to our attention that it does not comply with our "Code and Data Policy".
https://www.geoscientific-model-development.net/policies/code_and_data_policy.html
First, to access the climate forcing data used in your manuscript you cite a webpage (http://data.tpdc.ac.cn) which is not an acceptable repository according to the policy because:
It does not appear to have a published policy for data preservation over many years or decades (some flexibility exists over the precise length of preservation, but the policy must exist).
It does not appear to have a published mechanism for preventing authors from unilaterally removing material. Archives must have a policy which makes removal of materials only possible in exceptional circumstances and subject to an independent curatorial decision,
It does not appear to issue a persistent identifier such as a DOI or Handle for each precise dataset.
If we have missed a published policy which does in fact address this matter satisfactorily, please post a response linking to it. If you have any questions about this issue, please post them in a reply.
Also, to access the borehole temperature data and soil physical property datasets from the Beiluhe basin you state that they are available upon request. The policy of the journal clearly forbids this, and requires that all the code and data necessary to replicate a manuscript are available publicly and without limitations in acceptable repositories at the submission time. Due to this your manuscript should have never been accepted for Discussions and the fact that it is under peer review is irregular.
The GMD review and publication process depends on reviewers and community commentators being able to access, during the discussion phase, the code and data on which a manuscript depends, and on ensuring the provenance of replicability of the published papers for years after their publication. Please, therefore, publish the requrired data in one of the appropriate repositories and reply to this comment with the relevant information (link and a permanent identifier for it (e.g. DOI)) as soon as possible. We cannot have manuscripts under discussion that do not comply with our policy.
Later, if the Topical Editor decides to continue with the review or publication process of your manuscript and you are requested to upload a new version of it, then The 'Code and Data Availability’ section of your manuscript must also be modified to cite the new repository locations, and corresponding references added to the bibliography.
I must note that if you do not fix these problems, we cannot continue with the peer-review process or accept your manuscript for publication in GMD.
Juan A. Añel
Geosci. Model Dev. Executive Editor