2004a), Rock-wall temperatures in the Alps: Modelling their topographic distribution and regional differences

• Main Authors: Stephan Gruber, Martin Hoelzle, Wilfried Haeberli
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: KEY WORDS; rock temperatures; rock faces; Alps; mountain permafrost; energy balance; slope instability; rock fall; permafrost
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.491.677; http://www.geo.uzh.ch/~stgruber/pubs/gruber_2004-PPP3.pdf

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.