Rock-wall temperatures in the Alps: Modelling their topographic distribution and regional differences

• Published in: Permafrost and Periglacial Processes
• Main Authors: Gruber, S. (Stephan), Hoelzle, M. (Martin), Haeberli, W. (Wilfried)
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2004
• Subjects: Alps; Energy balance; Mountain permafrost; Rock faces; Rock fall; Rock temperatures; Slope instability; permafrost; Permafrost and Periglacial Processes
• Online Access: https://ir.library.carleton.ca/pub/19141; https://doi.org/10.1002/ppp.501

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 reanalysis 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.