This study focusses on the application of unmanned aerial vehicles (UAVs) to study crevassed glaciers on Svalbard (RIS-ID: 11148). Drones have several advantages for this type of research. They offer a possibility to investigate crevasses from a safe distance, without the hazards of glacier travel. Drones can take high-quality aerial imagery and are mostly independent of cloud coverage, which is an advantage compared to conventional remote sensing satellite data.
Three tidewater glacier fronts on Svalbard have been mapped using a DJI Phantom 4 Pro drone: Tunabreen, Fridtjovbreen, and in Mohnbukta. For each location, we have generated high-resolution digital elevation models (DEMs) using a photogrammetry method. We use these DEMs to study the influence of surface roughness on atmospheric heat exchange. The aerodynamic surface roughness parameters, which are enhancing heat transfer rates, are strongly linked to the size, depth, orientation, and the number of crevasses. The aerodynamic surface roughness can be identified from the DEMs and is used in thermodynamic models to estimate the heat transfer rates. In the context of rising atmospheric temperatures due to climate change, crevasses may be an important factor for glacier mass balancing.
Furthermore, we have tested a novel approach to use a multirotor drone for wind measurements based on the UAV inertial measurement unit (IMU) data. Pitch angle, yaw angle, and thrust variables can be used to estimate wind speed and wind direction while the drone is holding its position. To calibrate the method and to find the estimation functions, the drone is flown next to a wind measurement mast near Longyearbyen. Once a function between the IMU data and the wind speed has been established, the drone was used to take vertical wind profiles up to altitudes of 120m above ground.