Abstract

Rising temperatures or the complete thaw of permafrost in rock walls can affect their stability. Present as well as projected future atmospheric warming results in permafrost degradation and, as a consequence, makes knowledge of the spatial distribution and the temporal evolution of rock temperatures important. Rock-face near-surface temperatures have been measured over one year at 14 locations between 2500 and 4500 m a.s.l. in the Alps. Different slope aspects have been included in order to capture the maximum spatial differentiation of rock temperatures. These data were used to further develop and verify an energy-balance model that simulates daily surface temperatures over complex topography. Based on a 21-year (1982–2002) run of this model, spatial patterns of rock-face temperatures in the Swiss Alps are presented and discussed. This model provides a basis for the re-analysis of past rock-fall events with respect to permafrost degradation as well as for the simulation of future trends of rock temperatures. Furthermore, the spatial patterns of rock-wall temperatures provide a quantitative insight into the topography-related mechanisms affecting permafrost distribution in Alpine areas without local influence from snow cover or an active layer with a complex thermal offset.