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: Arctic Ocean; AWI_SeaIce; BEAST; DATE/TIME; Event label; FRAM; FRontiers in Arctic marine Monitoring; Image; LATITUDE; LONGITUDE; MOSAiC; MOSAiC20192020; Multibeam Echosounder; Imagenex DT101; Multidisciplinary drifting Observatory for the Study of Arctic Climate; Polarstern; PS122/2; PS122/2_18-19; PS122/2_19-27; PS122/2_20-23; PS122/2_21-36; PS122/2_22-45; PS122/2_23-29; PS122/2_24-70; PS122/2_25-44; PS122/3; PS122/3_29-14; PS122/3_31-17; PS122/3_31-75; PS122/3_32-11; PS122/3_32-33; PS122/3_33-27; PS122/3_34-20; PS122/3_36-125; PS122/3_36-24; PS122/3_37-20; PS122/3_38-50; PS122/3_39-20; PS122/3_39-77; PS122/4; PS122/4_44-162; PS122/4_44-206; PS122/4_45-61; PS122/4_46-37; PS122/4_47-31; PS122/4_48-4; PS122/4_49-105; PS122/5; PS122/5_59-269; Arctic; Sea ice
• Online Access: https://doi.pangaea.de/10.1594/PANGAEA.945846; https://doi.org/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 resulting from the chosen number of beams and the sector size was 0.25°. The ping rate was automatically set and was based on the range setting, numbers of beams selected and specification of the computer system used for operation. The profile setup options were enabled profile point detection, maximum return, no along track averaging, no bottom following, and no pipe detect. A constant sound velocity of 1437 m/s was applied. Returns from three points were averaged to derive the distance from the MBES to the ice underside. Subtracting the distance to the ice from the vehicle depth yielded the sea-ice draft. More technical details are available here: https://imagenex.com/products/dt101xi. The software to record operate the MBES and record data is available from the Imagenex website (https://imagenex.com/interior-page/software-dowload). Data were processed using the CARIS HIPS and SIPS software (Teledyne CARIS, Fredericton, NB, Canada) applying swath and subset editors for data cleaning. The appreciation '_HR' in ...