ALBERT

Description: The Author(s), 2022. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Rabe, B., Heuze, C., Regnery, J., Aksenov, Y., Allerholt, J., Athanase, M., Bai, Y., Basque, C., Bauch, D., Baumann, T. M., Chen, D., Cole, S. T., Craw, L., Davies, A., Damm, E., Dethloff, K., Divine, D., Doglioni, F., Ebert, F., Fang, Y-C., Fer, I., Fong, A. A., Gradinger, R., Granskog, M. A., Graupner, R., Haas, C., He, H., He, Y., Hoppmann, M., Janout, M., Kadko, D., Kanzow, T., Karam, S., Kawaguchi, Y., Koenig, Z., Kong, B., Krishfield, R. A., Krumpen, T., Kuhlmey, D., Kuznetsov, I., Lan, M., Laukert, G., Lei, R., Li, T., Torres-Valdés, S., Lin, L,. Lin, L., Liu, H., Liu, N., Loose, B., Ma, X., MacKay, R., Mallet, M., Mallett, R. D. C., Maslowski, W., Mertens, C., Mohrholz, V., Muilwijk, M., Nicolaus, M., O’Brien, J. K., Perovich, D., Ren, J., Rex, M., Ribeiro, N., Rinke, A., Schaffer, J., Schuffenhauer, I., Schulz, K., Shupe, M. D., Shaw, W., Sokolov, V., Sommerfeld, A., Spreen, G., Stanton, T., Stephens, M., Su, J., Sukhikh, N., Sundfjord, A., Thomisch, K., Tippenhauer, S., Toole, J. M., Vredenborg, M., Walter, M., Wang, H., Wang, L., Wang, Y., Wendisch, M., Zhao, J., Zhou, M., & Zhu, J. Overview of the MOSAiC expedition: physical oceanography. Elementa: Science of the Anthropocene, 10(1), (2022): 1, https://doi.org/10.1525/elementa.2021.00062.

Description: Arctic Ocean properties and processes are highly relevant to the regional and global coupled climate system, yet still scarcely observed, especially in winter. Team OCEAN conducted a full year of physical oceanography observations as part of the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC), a drift with the Arctic sea ice from October 2019 to September 2020. An international team designed and implemented the program to characterize the Arctic Ocean system in unprecedented detail, from the seafloor to the air-sea ice-ocean interface, from sub-mesoscales to pan-Arctic. The oceanographic measurements were coordinated with the other teams to explore the ocean physics and linkages to the climate and ecosystem. This paper introduces the major components of the physical oceanography program and complements the other team overviews of the MOSAiC observational program. Team OCEAN’s sampling strategy was designed around hydrographic ship-, ice- and autonomous platform-based measurements to improve the understanding of regional circulation and mixing processes. Measurements were carried out both routinely, with a regular schedule, and in response to storms or opening leads. Here we present along-drift time series of hydrographic properties, allowing insights into the seasonal and regional evolution of the water column from winter in the Laptev Sea to early summer in Fram Strait: freshening of the surface, deepening of the mixed layer, increase in temperature and salinity of the Atlantic Water. We also highlight the presence of Canada Basin deep water intrusions and a surface meltwater layer in leads. MOSAiC most likely was the most comprehensive program ever conducted over the ice-covered Arctic Ocean. While data analysis and interpretation are ongoing, the acquired datasets will support a wide range of physical oceanography and multi-disciplinary research. They will provide a significant foundation for assessing and advancing modeling capabilities in the Arctic Ocean.

Description: The following projects and funding agencies contributed to this work: Why is the deep Arctic Ocean Warming is funded by the Swedish Research Council, project number 2018-03859, and berth fees for this project were covered by the Swedish Polar Research Secretariat; The Changing Arctic Ocean (CAO) program, jointly funded by the United Kingdom Research and Innovation (UKRI) Natural Environment Research Council (NERC) and the Bundesministerium für Bildung und Forschung (BMBF), in particular, the CAO projects Advective Pathways of nutrients and key Ecological substances in the ARctic (APEAR) grants NE/R012865/1, NE/R012865/2, and #03V01461, and the project Primary productivity driven by Escalating Arctic NUTrient fluxeS grant #03F0804A; The Research Council of Norway (AROMA, grant no 294396; HAVOC, grant no 280292; and CAATEX, grant no 280531); Collaborative Research: Thermodynamics and Dynamic Drivers of the Arctic Sea Ice Mass Budget at Multidisciplinary drifting Observatory for the Study of the Arctic Climate; National Science Foundation (NSF) projects 1723400, Stanton; OPP-1724551, Shupe; The Helmholtz society strategic investment Frontiers in Arctic Marine monitoring (FRAM); Deutsche Forschungsgemeinschaft (German Research Foundation) through the Transregional Collaborative Research Centre TRR 172 “ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)3” (grant 268020496); The Japan Society for the Promotion of Science (grant numbers JP18H03745, JP18KK0292, and JP17KK0083) and the COLE grant of U. Tokyo; National Key Research and Development Plan Sub-Project of Ministry of Science and Technology of China (2016YFA0601804), “Simulation, Prediction and Regional Climate Response of Global Warming Hiatus”, 2016/07-2021/06; National Science Foundation grant number OPP-1756100 which funded two of the Ice-Tethered Profilers and all the Ice-Tethered Profiler deployments; Chinese Polar Environmental Comprehensive Investigation and Assessment Programs, funded by the Chinese Arctic and Antarctic Administration; Marine Science and Technology Fund of Shandong Province for Qingdao National Laboratory for Marine Science and Technology (Grant: 2018SDKJ0104-1) and Chinese Natural Science Foundation (Grant: 41941012); UK NERC Long-term Science Multiple Centre National Capability Programme “North Atlantic Climate System Integrated Study (ACSIS)”, grant NE/N018044/1; The London NERC Doctoral Training Partnership grant (NE/L002485/1) which funded RDCM; NSF grant number OPP-1753423, which funded the 7Be tracer –measurements; and The Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung (AWI) through its projects: AWI_OCEAN, AWI_ROV, AWI_ICE, AWI_SNOW, AWI_ECO, AWI_ATMO, and AWI_BGC.

Description: The MacArtney Triaxus extended version is a remotely operated towed vehicle (ROTV). It is towed behind the ship between 2 and 10 knots and can undulate in a saw tooth pattern between a few meters below the surface and 350m depth. The umbilical provides power and a fiber optic link to sensors that are mounted on the Triaxus (see SensorWeb). The different data streams require separate processing. Here we report the data from the Seabird 911+ dual pumped CTD system mounted on the Triaxus. The provided data are 0.5 second or 0.5 meter averages. The operations included profiling mode and constant depth mode. Depth data comes from the CTD's pressure sensor. Position data (latitude, longitude) comes from the ship's GPS system and is corrected for the length of the umbilical behind the ship. Standard Seabird Data processing (SBE Data Processing) were applied. A front in the open ocean region in the vicinity of the ice edge in Fram Strait was searched for with a ~100km long constant depth Triaxus transect on July 8. When a front had been found, it was surveyed in 3D by parallel UCTD sections and drifters were deployed. The front was followed until July 16 with the repeat of parallel UCTD and Triaxus sections. In total 17 sections were occupied with the Triaxus.

Description: The MacArtney Triaxus extended version is a remotely operated towed vehicle (ROTV). It is towed behind the ship between 2 and 10 knots and can undulate in a saw tooth pattern between a few meters below the surface and 350m depth. The umbilical provides power and a fiber optic link to sensors that are mounted on the Triaxus (see SensorWeb). The data collected by the sensors were recorded on separate computers, one computer per sensor (including the flight information from the Triaxus itself). Thus, there are 7 separate data streams saved in separate folders plus a folder with metadata information about the different dives. During long Triaxus operations, new data files would be started approximately every 4 hours, because some of the employed software programs do not allow for backing up of the files while they are still being written to. A front in the open ocean region in the vicinity of the ice edge in Fram Strait was searched for with a ~100km long constant depth Triaxus transect on July 8. When a front had been found, it was surveyed in 3D by parallel UCTD sections and drifters were deployed. The front was followed until July 16 with the repeat of parallel UCTD and Triaxus sections. In total 17 sections were occupied with the Triaxus.

Description: Time-series data of physical oceanography and ocean current velocities were obtained from mooring F3-19 in the Fram Strait from July 2020 to July 2022 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV MARIA S. MERIAN expedition MSM93 and recovered during RV POLARSTERN expedition PS131. The attached archive contains raw data files of three Seabird SBE37 MicroCATs (nominal depths: 49m, 245m, 764m; sampling interval 30m/1h), one RDI Longranger ADCP (nominal depth: 406m; sampling interval 2h) and two Nortek Aquadopp current meter (nominal depths: 763m, 1070m; sampling interval 1h). Auxiliary information such as sensor calibration sheets, mooring diagrams, and schedule files are also provided, if applicable.

Description: Time-series data of physical & biological oceanography, nutrient biogeochemistry and molecular biology were obtained from mooring F4-W-1 in the Fram Strait in July 2018 - August 2019 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS114, and recovered during PS121. The attached archive contains raw data files of a profiling SBE19plus system on an NGK winch (nominal depth: 153m), two Seabird SBE37 microcats (nominal depths: 157m, 252m; sampling interval 1h), one Satlantics SUNA nitrate sensor (nominal depth: 252m; sampling interval 4h), one Sunburst SAMI-pCO2 sensor (nominal depth: 252m; sampling interval 1h) and one Sunburst SAMI-pH sensor (nominal depth: 252m; sampling interval 3h). The mooring also included a McLane RAS water sampler (nominal depth: 252m). Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.

Description: Time series data of physical oceanography (seawater conductivity, temperature, pressure, salinity), ocean current velocities and hydroacoustics were obtained from mooring F4-18 in the Fram Strait in July 2018 - August 2019 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during Polarstern expedition PS114, and recovered during PS121. The attached archive contains raw data files of 6 Seabird SBE37 microcats (nominal depths: 63m, 150m, 250m, 500m, 731m, 1202m; sampling interval 1h), one RDI Workhorse Longranger ADCP (depth: 380m; sampling interval: 1h) and two AADI RCM11 current meters (depths: 730m, 1208m; sampling interval: 2h). The mooring also included a Develogic Sonovault (nominal depth: 800m; data archived elsewhere). Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.

Description: Time-series data of physical oceanography, nutrient biogeochemistry, molecular biology, and carbon/particle export were obtained from mooring F4-S-3 in the Fram Strait in July 2018 - August 2019 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV POLARSTERN expedition PS114, and recovered during PS121. The attached archive contains raw data files of two Seabird SBE37 microcats (nominal depths: 23m, 50m; sampling interval 1h), one Wetlabs ECO PAR sensor (nominal depth: 23m; sampling interval 1h), one Wetlabs ECO Triplet fluorometer (nominal depth: 23m; sampling interval 2h), one Satlantic SUNA nitrate sensor (nominal depth: 23m; sampling interval 4h), one Sunburst SAMI-pCO2 sensor (nominal depth: 23m; sampling interval 1h) and one Sunburst SAMI-pH sensor (nominal depth: 23m; sampling interval 3h). The mooring also included a McLane RAS water sampler (nominal depth: 23m), a McLane PPS phytoplankton sampler (nominal depth: 25m) and two sediment traps (nominal depths: 204m, 613m). Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.

Description: Time series data of physical oceanography (seawater conductivity, temperature, pressure, salinity) and ocean current velocities were obtained from mooring F1-17 in the Fram Strait in September 2018 - July 2019 as part of the Helmholtz infrastructure program Frontiers in Arctic Marine Monitoring (FRAM) and the long-term monitoring program at AWI HAUSGARTEN. The mooring was deployed during RV MARIA S. MERIAN expedition MSM76 and recovered during MSM93. The attached archive contains raw data files of one Seabird SBE37 microcat (nominal depth: 345m; sampling interval 20 min) and one RDI Quartermaster ADCP (nominal depth: 345m; sampling interval 1h). Although the mooring was recovered in July 2020, data is only available until July 2019 due to instrument power failures. The records show also evidence that the mooring was moved at the end of November 2018, most likely by a bottom trawler. Auxiliary information such as sensor calibration sheets, mooring diagrams and schedule files are also provided, if applicable.