Consequences of permafrost degradation for Arctic infrastructure – bridging the model gap between regional and engineering scales

Abstract. Infrastructure built on perennially frozen ice-rich ground relies heavily thermally stable subsurface conditions. Climate-warming-induced deepening of thaw puts such infrastructure at risk failure. For better assessing the large-scale future damage to Arctic infrastructure, improved strategies for model-based approaches are urgently needed. We used laterally coupled 1D heat conduction model CryoGrid3 simulate permafrost degradation affected by linear infrastructure. present a case study gravel road continuous (Dalton highway, Alaska) and forced our under historical strong warming conditions (following RCP8.5 scenario). As expected, presence in leads higher net flux entering compared reference run without thus rate thaw. Further, results suggest that failure is likely consequence lateral destabilisation due talik formation beside rather than direct top-down thawing active layer below centre. In line with previous studies, we identify enhanced snow accumulation ponding (both presence) as key factors increased soil temperatures degradation. Using differing horizontal resolutions show it possible capture these their impact dynamics low number units, underlining potential approach use pan-Arctic assessments. Our general two-phase behaviour degradation: an initial phase slow gradual thaw, followed increase rates after exceedance critical warming. The timing this transition magnitude acceleration differ strongly between undisturbed tundra infrastructure-affected ground. current which do not explicitly take into account designs underestimate By using infer outcomes from more complex 2D 3D models, but model's computational efficiency allows us long-term climate change impacts simulations underline crucial consider when planning constructing highly unstable state can well occur within service lifetime (about 30 years) construction. Such even be triggered coming decade high northern latitude displays cold relatively today.