Aerodynamic Surface Roughness of Crevassed Glaciers from UAV Mapping, RiS ID 11148

Sensible and latent heat fluxes will play an increasingly important role in the melt rate of glaciers regarding global warming. Crevasses on glaciers make the surface rougher and thus leading to more turbulence what again is expected to intensify the atmospheric heat exchange. However, energy balance models often use one uniform aerodynamic surface roughness length z0 - a parameter used to describe the turbulent heat exchange - for the whole glacier. This does not represent the spatial variability of the glacier's roughness. Drone surveying data can now constitute a possibility to prevent this problem and evaluate proper z0 values for crevassed glaciers. Therefore, in my master thesis we will find an approach to calculate the roughness length out of digital elevation models (DEMs). The DEMs themselves will be extracted from drone-based pictures with a structure from motion (SFM) method. This approach is expected to lead to z0 values that account for the large roughness of crevasses. Thus, we assume that our heat exchange rates can better represent the actual melt rate of glaciers in models.