• Different mechanisms of Arctic first-year sea-ice ridge consolidation observed during the MOSAiC expedition 

      Salganik, Evgenii; Lange, Benjamin; Itkin, Polona; Divine, Dmitry; Katlein, Christian; Nicolaus, Marcel; Hoppmann, Mario; Neckel, Niklas; Ricker, Robert; Høyland, Knut Vilhelm; Granskog, Mats (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-22)
      Sea-ice ridges constitute a large fraction of the ice volume in the Arctic Ocean, yet we know little about the evolution of these ice masses. Here we examine the thermal and morphological evolution of an Arctic firstyear sea-ice ridge, from its formation to advanced melt. Initially the mean keel depth was 5.6 m and mean sail height was 0.7 m. The initial rubble macroporosity (fraction of seawater ...
    • Overview of the MOSAiC expedition: Physical oceanography 

      Rabe, Benjamin; Baumann, Till Martin; Divine, Dmitry; Fer, Ilker; Gradinger, Rolf Rudolf; Granskog, Mats; Koenig, Zoe Charlotte; Muilwijk, Morven; Sundfjord, Arild; Heuze´, Céline; Regnery, Julia; Aksenov, Yevgeny; Allerholt, Jacob; Athanase, Marylou; Bai, Youcheng; Basque, Chris; Bauch, Dorothea; Chen, Dake; Cole, Sylvia T.; Craw, Lisa; Davies, Andrew; Damm, Ellen; Dethloff, Klaus; Doglioni, Francesca; Ebert, Falk; Fang, Ying-Chih; Fong, Allison A.; Graupner, Rainer; Haas, Christian; He, Hailun; He, Yan; Hoppmann, Mario; Janout, Markus; Kadko, David; Kanzow, Torsten; Karam, Salar; Kawaguchi, Yusuke; Kong, Bin; Krishfield, Richard A.; Krumpen, Thomas; Kuhlmey, David; Kuznetsov, Ivan; Lan, Musheng; Laukert, Georgi; Lei, Ruibo; Li, Lao; Torres-Valdés, Sinhué; Lin, Lina; Lin, Long; Liu, Hailong; Liu, Na; Loose, Brice; Ma, Xiaobing; McKay, Rosalie; Mallet, Maria; Mallet, Robbie D .C.; Maslowski, Wieslaw; Mertens, Christian; Mohrholz, Volker; Nicolaus, Marcel; O'Brien, Jeffrey K.; Perovich, Donald; Ren, Jian; Rex, Markus; Ribeiro, Natalia; Rinke, Annette; Sokolov, Vladimir; Sommerfeld, Anja; Spreen, Gunnar; Stanton, Timothy; Stephens, Mark; Su, Jie; Sukhikh, Natalia; Thomisch, Karolin; Tippenhauer, Sandra; Toole, John M.; Vredenborg, Myriel; Walter, Maren; Wang, Hangzhou; Wang, Lei; Wang, Yuntao; Wendisch, Manfred; Zhao, Jinping; Zhou, Meng; Zhu, Jialiang (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-07)
      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. ...
    • Overview of the MOSAiC expedition: Snow and sea ice 

      Marcel, Nicolaus; Perovich, Donald; Spreen, Gunnar; Granskog, Mats; Divine, Dmitry; Gerland, Sebastian; Gradinger, Rolf Rudolf; Høyland, Knut Vilhelm; Salganik, Evgenii; Albedyll, Luisa von; Angelopoulos, Michael; Anhaus, Philipp; Arndt, Stefanie; Belter, H. Jakob; Bessonov, Vladimir; Birnbaum, Gerit; Brauchle, Jörg; Calmer, Radiance; Cardellach, Estel; Cheng, Bin; Clemens-Sewall, David; Dadic, Ruzica; Damm, Ellen; de Boer, Gijs; Demir, Oguz; Dethloff, Klaus; Fong, Allison A.; Fons, Steven; Frey, Markus M.; Fuchs, Niels; Gabarro, Carolina; Goessling, Helge F.; Haapala, Jari; Haas, Christian; Hamilton, Jonathan; Hannula, Henna-Reetta; Hendricks, Stefan; Herber, Andreas; Heuze´, Céline; Hoppmann, Mario; Huntemann, Marcus; Hutchings, Jennifer K.; Kaleschke, Lars; Katlein, Christian; Kolabutin, Nikolai; Krampe, Daniela; Savstrup Kristensen, Steen; Krumpen, Thomas; Kurtz, Nathan; Lampert, Astrid; Lange, Benjamin Allen; Lei, Ruibo; Light, Bonnie; Linhardt, Felix; Liston, Glen E.; Loose, Brice; Macfarlane, Amy R.; Mahmud, Mallik; Matero, Ilkka O.; Maus, Sönke; Morgenstern, Anne; Naderpour, Reza; Nandan, Vishnu; Niubom, Alexey; Oggier, Marc; Oppelt, Natascha; Pätzold, Falk; Perron, Christophe; Petrovsky, Tomasz; Pirazzini, Roberta; Polashenski, Chris; Rabe, Benjamin; Raphael, Ian A.; Regnery, Julia; Rex, Markus; Ricker, Robert; Riemann-Campe, Kathrin; Rinke, Annette; Rohde, Jan; Scharien, Randall K.; Schiller, Martin; Schneebeli, Martin; Semmling, Maximilian; Shimanchuk, Egor; Stroeve, Julienne; Thielke, Linda; Timofeeva, Anna; Tonboe, Rasmus Tage; Tavri, Aikterini; Tsamados, Michel; Wagner, David N.; Watkins, Daniel; Webster, Melinda; Wendisch, Manfred (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-02-07)
      Year-round observations of the physical snow and ice properties and processes that govern the ice pack evolution and its interaction with the atmosphere and the ocean were conducted during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition of the research vessel Polarstern in the Arctic Ocean from October 2019 to September 2020. This work was embedded ...
    • Platelet ice under Arctic pack ice in winter 

      Katlein, Christian; Mohrholz, Volker; Sheikin, Igor; Itkin, Polona; Divine, Dmitry; Stroeve, Julienne C.; Jutila, Arttu; Krampe, Daniela; Shimanchuk, Egor; Raphael, Ian; Rabe, Benjamin; Kuznetsov, Ivan; Mallet, Maria; Liu, Hailong; Hoppmann, Mario; Fang, Ying‐Chih; Dumitrascu, Adela; Arndt, Stefanie; Anhaus, Philipp; Nicolaus, Marcel; Matero, Ilkka; Oggier, Marc; Eicken, Hajo; Haas, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-08-17)
      The formation of platelet ice is well known to occur under Antarctic sea ice, where subice platelet layers form from supercooled ice shelf water. In the Arctic, however, platelet ice formation has not been extensively observed, and its formation and morphology currently remain enigmatic. Here, we present the first comprehensive, long‐term in situ observations of a decimeter thick subice platelet ...
    • Sea-ice decline could keep zooplankton deeper for longer 

      Flores, Hauke; Veyssière, Gaëlle; Castellani, Giulia; Wilkinson, Jeremy; Hoppmann, Mario; Karcher, Michael; Valcic, Lovro; Cornils, Astrid; Geoffroy, Maxime; Nicolaus, Marcel; Niehoff, Barbara; Priou, Pierre; Schmidt, Katrin; Stroeve, Julienne (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-08-28)
      As Arctic sea ice deteriorates, more light enters the ocean, causing largely unknown effects on the ecosystem. Using an autonomous biophysical observatory, we recorded zooplankton vertical distribution under Arctic sea ice from dusk to dawn of the polar night. Here we show that zooplankton ascend into the under-ice habitat during autumn twilight, following an isolume of 2.4 × 10<sup>−4</sup>  ...
    • Surface-based Ku-and Ka-band polarimetric radar for sea ice studies 

      Stroeve, Julienne C.; Nandan, Vishnu; Willatt, Rosemary; Tonboe, Rasmus; Hendricks, Stefan; Ricker, Robert; Mead, James; Mallett, Robbie; Huntemann, Marcus; Itkin, Polona; Schneebeli, Martin; Krampe, Daniela; Spreen, Gunnar; Wilkinson, Jeremy; Matero, Ilkka; Hoppmann, Mario; Tsamados, Michel (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-04)
      To improve our understanding of how snow properties influence sea ice thickness retrievals from presently operational and upcoming satellite radar altimeter missions, as well as to investigate the potential for combining dual frequencies to simultaneously map snow depth and sea ice thickness, a new, surface-based, fully polarimetric Ku- and Ka-band radar (KuKa radar) was built and deployed ...
    • Thermodynamic and dynamic contributions to seasonal Arctic sea ice thickness distributions from airborne observations 

      von Albeldyll, Luisa; Hendricks, Stefan; Grodofzig, Raphael; Krumpen, Thomas; Arndt, Stefanie; Belter, H. Jakob; Birnbaum, Gerit; Cheng, Bin; Hoppmann, Mario; Hutchings, Jennifer; Itkin, Polona; Lei, Ruibo; Nicolaus, Marcel; Ricker, Robert; Rohde, Jan; Suhrhoff, Mira; Timofeeva, Anna; Watkins, Daniel; Webster, Melinda; Haas, Christian (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-04-18)
      Sea ice thickness is a key parameter in the polar climate and ecosystem. Thermodynamic and dynamic processes alter the sea ice thickness.The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition provided a unique opportunity to study seasonal sea ice thickness changes of the same sea ice. We analyzed 11 large-scale (*50 km) airborne electromagnetic sea thickness ...
    • Thin and transient meltwater layers and false bottoms in the Arctic sea ice pack-Recent insights on these historically overlooked features 

      Smith, Madison M.; Muilwijk, Morven; Chierici, Melissa; Fer, Ilker; Fransson, Agneta; Gardner, Jessie; Granskog, Mats; Müller, Oliver; Salganik, Evgenii; Angot, He´le`ne; Chamberlain, Emelia J.; Droste, Elise S.; Karam, Salar; Webb, Alison L.; Archer, Stephen D.; Beck, Ivo; Blomquist, Byron W.; Bowman, Jeff; Boyer, Matthew; Bozzato, Deborah; Creamean, Jessie; D’Angelo, Alessandra; Delille, Bruno; Fong, Allison A.; Fuchs, Niels; Hoppe, Clara J. M.; Hoppema, Mario; Hoppmann, Mario; Mock, Thomas; Muller, Sofia; Nicolaus, Marcel; Nomura, Daiki; Petääja, Tuukka; Schmale, Julia; Schmidt, Katrin; Schulz, Kirstin M.; Shupe, Matthew D.; Stefels, Jacqueline; Thielke, Linda; Tippenhauer, Sandra; Ulfsbo, Adam; van Leeuwe, Maria; Webster, Melinda; Yoshimura, Masaki; Zhan, Liyang (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-09-07)
      The rapid melt of snow and sea ice during the Arctic summer provides a significant source of low-salinity meltwater to the surface ocean on the local scale. The accumulation of this meltwater on, under, and around sea ice floes can result in relatively thin meltwater layers in the upper ocean. Due to the small-scale nature of these upper-ocean features, typically on the order of 1 m thick or less, ...
    • Wind redistribution of snow impacts the Ka- and Ku-band radar signatures of Arctic sea ice 

      Nandan, Vishnu; Willatt, Rosemary; Mallett, Robbie; Stroeve, Julienne; Geldsetzer, Torsten; Scharien, Randall; Tonboe, Rasmus; Yackel, John; Landy, Jack Christopher; Clemens-Sewall, David; Jutila, Arttu; Wagner, David N.; Krampe, Daniela; Huntemann, Marcus; Mahmud, Mallik; Jensen, David; Newman, Thomas; Hendricks, Stefan; Spreen, Gunnar; Macfarlane, Amy; Schneebeli, Martin; Mead, James; Ricker, Robert; Gallagher, Michael; Duguay, Claude; Raphael, Ian; Polashenski, Chris; Tsamados, Michel; Matero, Ilkka; Hoppmann, Mario (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-06-02)
      Wind-driven redistribution of snow on sea ice alters its topography and microstructure, yet the impact of these processes on radar signatures is poorly understood. Here, we examine the effects of snow redistribution over Arctic sea ice on radar waveforms and backscatter signatures obtained from a surface-based, fully polarimetric Ka- and Ku-band radar at incidence angles between 0∘ (nadir) and 50∘. ...