Sea-ice draft during the MOSAiC expedition 2019/20 ...

• Main Authors: Katlein, Christian, Anhaus, Philipp, Arndt, Stefanie, Krampe, Daniela, Lange, Benjamin Allen, Matero, Ilkka, Regnery, Julia, Rohde, Jan, Schiller, Martin, Nicolaus, Marcel
• Format: Dataset
• Language: English
• Published: PANGAEA 2022
• Subjects: MOSAiC20192020; Multibeam Echosounder; Remotely operated vehicle ROV; Sea ice; Sea-ice draft; Sea-ice thickness; Event label; DATE/TIME; LATITUDE; LONGITUDE; Image; Raster graphic, GeoTIFF format; Text file; Remotely operated sensor platform BEAST; Quicklook; Multibeam echosounder, Imagenex DT101; PS122/2; PS122/3; PS122/4; PS122/5; Polarstern; FRontiers in Arctic marine Monitoring FRAM; Multidisciplinary drifting Observatory for the Study of Arctic Climate MOSAiC; Sea Ice Physics @ AWI AWI_SeaIce; Arctic; Canada; Stripe; Zenit
• Online Access: https://dx.doi.org/10.1594/pangaea.945846; https://doi.pangaea.de/10.1594/PANGAEA.945846

The three-dimensional under-ice topography has been mapped regularly during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition in 2019/20 (Nicolaus et al., 2022). We used a high-speed, high-resolution multibeam echosounder system (MBES, Imagenex DT101, Port Coquitlam, BC, Canada) attached to a remotely operated vehicle (ROV, M500, Ocean Modules, Åtvidaberg, Sweden, Katlein et al., 2017). The system was operated directly from the sea ice during most dive days on all legs of the MOSAiC expedition. The area covered had a radius of approximately 280 m. Standard multibeam surveys were performed at a dive depth of 20 m while high-resolution surveys at 10 m depth.The MBES consists of a multibeam sonar, an integrated Sound Velocity Probe (SVP), and a Motion Reference Unit (MRU). The operating frequency was 240 kHz. The sonar was used with 480 beams with a swath width of 120° (across track) x 3° (along track) and an effective beam width of 0.75°. The angular resolution ... : Version 1.0, preliminary release August 2021: This dataset is an early release with QC data, but the data set is not corrected or polished to every aspect. It can be used, but issues and pitfalls remain. Known issues are the following:• Roll calibration of the multibeam mounting is imperfect leading to stripe patterns and surface tilts in some datasets.• Draft values have not been checked for absolute height. Cross-check with drillings or open water patches before using, significant offsets can be possible.• Positioning accuracy of the ROV varied, hence some features can be displaced by meters, while lateral accuracy within individual swaths is good.• Some datasets exhibit bulges over the zenit beams .• Due to sound velocity differences, the acoustic position can be scaled and distorted relative to precise surface measurements (e.g. laser scanner).• Not all edge beams have been cleaned up perfectly.• No sound velocity correction.• Reflections might originate from false bottoms in some cases.• Some data on ...