Snow accumulates even on steep rock walls, influencing rock temperature

“Fieldwork is very important to understand nature,” believes Anna Haberkorn. Indeed, it forms a central part of her dissertation. The meteor­ologist is investigating snow cover on rock walls, where it was previously assumed very little snow would ac­cumulate, due to its tendency to slide off. This is wrong, according to Haberkorn: “My investigations show that snow cover between one and two meters thick can form on rock walls, piling up on ledges.” It is an unusual kind of snow cover, with a conspicuous number of melt crusts and weakly bonded layers, and there is very often a basal ice layer. “The ice prevents meltwater from pen­etrating into the rock and bringing warmth into it,” explains Haberkorn. This fact and the snow cover itself, which has an insulating effect and alters heat exchange, have an im­portant influence on the thermal regime of rock – which, in turn, influences its stability. Using meteor­ological data and terrain-based in­formation, Haberkorn can simulate the snow cover and rock temperature at individual points using the SNOWPACK computer model. She would now like to carry out such simulations for entire rock walls, and perhaps even for a whole mountain. A little office work is now on the agenda for this passionate moun­taineer. (Birgit Ottmer, Diagonal 1/16)