Feedbacks and timescales in the modelled transient response of debris-covered glaciers Hardmeier, Florian Ferguson, James Vieli, Andreas ddc:550 ddc:000 Glaciers worldwide are becoming increasingly debris-covered, yet many aspects within the coupled glacier-debris system are not well-understood. While the insulating effect of continuous debris layers is well-known, the transient feedbacks with glacier dynamics are poorly understood. The main aim of this study is to better understand the complex transient glacier response and debris-induced feedbacks through numerical flow modelling. We present an improved flowline model that couples ice flow, depth-resolved debris transport, and debris cover impact on mass balance. This approach allows for a detailed examination of the dynamics of debris-covered glaciers under transient forcing conditions of climate and debris input over extended timescales. Our results indicate that low-amplitude, decade-scale variability in debris or climate forcing does not substantially impact glacier evolution. However, large debris supply events can have a sustained impact. We find that debris-covered glacier response to warming climate forcing is non-monotonic, with distinct phases of thinning, retreat, and long-term re-advance. We attribute this to a separate, longer timescale process of englacial debris transport. Additionally, feedbacks in the englacial debris trajectory and complex bed topography further amplify the non-linear pattern of retreat in the transient glacier response to warming. Copernicus Publications 2026 info:eu-repo/semantics/article doc-type:Article Article http://purl.org/coar/resource_type/c_2df8fbb1 https://research-explorer.ista.ac.at/record/23091 https://research-explorer.ista.ac.at/download/23091/23105 Hardmeier F, Ferguson J, Vieli A. Feedbacks and timescales in the modelled transient response of debris-covered glaciers. <i>The Cryosphere</i>. 2026;20(9):5365-5392. doi:<a href="https://doi.org/10.5194/tc-20-5365-2026">10.5194/tc-20-5365-2026</a> eng info:eu-repo/semantics/altIdentifier/doi/10.5194/tc-20-5365-2026 info:eu-repo/semantics/altIdentifier/issn/1994-0416 info:eu-repo/semantics/altIdentifier/e-issn/1994-0424 https://creativecommons.org/licenses/by/4.0/ info:eu-repo/semantics/openAccess