Kilometer-scale digital elevation models of the sea ice surface during MOSAiC with Airborne Laserscanning (ALS)

• Main Authors: Hutter, Nils, Hendricks, Stefan, Jutila, Arttu, Ricker, Robert, Albedyll, Luisa von, Birnbaum, Gerit, Haas, Christian
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Sea ice
• Online Access: https://epic.awi.de/id/eprint/55405/; https://hdl.handle.net/10013/epic.6653caac-62d8-40cb-8f87-430814842eac

An integrated sensor platform including an inertial navigation system (INS) and a commercial airborne laser scanner (ALS) among other sensor was mounted in the cargo compartment in one of the Polarstern helicopters during MOSAiC. ALS data was acquired from more than 60 flights between October 2019 and September 2020 with a range of survey types intended to map changes of the sea ice surface during the full annual cycle at high spatial resolution and coverage. Here we provide an overview of the collected data and the challenge of achieving centimeter elevation accuracy with a helicopter platform at high polar latitudes. The high spatial resolution and repeated coverage of the larger area around Polarstern allow to study various surface features (e.g. pressure ridges, floes, melt ponds, snow drifts, etc.), their seasonal evolution, and their impact on atmosphere and ocean. We outline methods to identify individual floes and surface types using both measured freeboard and surface reflectance. The identified surface features can be followed in time using automated feature tracking for consecutive flights to study the dynamic and thermodynamic processes that shape the sea-ice surface. Finally, we introduce a framework to train novel data methods with the transect snow and ice measurements to predict the snow and sea-ice thickness based on the surface structure in the ALS freeboard data.