Permafrost distribution from BTS measurements (Sierra de Telera, Central Pyrenees, Spain): assessing the importance of solar radiation in a mid‐elevation shaded mountainous area

Permafrost distribution was predicted from measurements of basal temperatures of the winter snow cover using a GIS‐based empirical–statistical modelling approach in a mid‐elevation mountainous area, the northern slope of the Sierra de Telera (central Pyrenees, Spain). A total of 223 basal temperature of snow (BTS) measurements were made over 3 years and a multiple linear regression analysis was performed to model the relationship between BTS measurements and three predictor variables: May solar radiation, elevation and snow‐cover persistence. The snow‐cover persistence factor proved non‐significant and was excluded from the final regression analysis. The model used was statistically significant, and predicted permafrost distribution moderately well (K = 0.52) and with an overall accuracy of 0.79. The results show the importance of solar radiation as an explanatory variable for permafrost conditions in a mid‐elevation mountain area with steep topography.