• 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 ...
    • Retrieval of Snow Depth on Arctic Sea Ice From Surface-Based, Polarimetric, Dual-Frequency Radar Altimetry 

      Willatt, Rosemary; Stroeve, Julienne; Nandan, Vishnu; Newman, Thomas; Mallett, Robbie; Hendricks, Stefan; Ricker, Robert; Mead, James; Itkin, Polona; Tonboe, Rasmus; Wagner, David N.; Spreen, Gunnar; Liston, Glen; Schneebeli, Martin; Krampe, Daniela; Tsamados, Michel; Demir, Oguz; Wilkinson, Jeremy; Jaggi, Matthias; Zhou, Lu; Huntemann, Marcus; Raphael, Ian A.; Jutila, Arttu; Oggier, Marc (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-10-18)
      Snow depth on sea ice is an Essential Climate Variable and a major source of uncertainty in satellite altimetry-derived sea ice thickness. During winter of the MOSAiC Expedition, the “KuKa” dual-frequency, fully polarized Ku- and Ka-band radar was deployed in “stare” nadir-looking mode to investigate the possibility of combining these two frequencies to retrieve snow depth. Three approaches ...
    • 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>  ...
    • Snow and Ice Thickness Retrievals Using GNSS-R: Preliminary Results of the MOSAiC Experiment 

      Munoz-Martin, Joan Francesc; Perez, Adrian; Camps, Adriano; Ribó, Serni; Cardellach, Estel; Stroeve, Julienne; Nandan, Vishnu; Itkin, Polona; Tonboe, Rasmus; Hendricks, Stefan; Huntemann, Marcus; Spreen, Gunnar; Pastena, Massimiliano (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-12-10)
      The FSSCat mission was the 2017 ESA Sentinel Small Satellite (S⌃3) Challenge winner and the Copernicus Masters competition overall winner. It was successfully launched on 3 September 2020 onboard the VEGA SSMS PoC (VV16). FSSCat aims to provide coarse and downscaled soil moisture data and over polar regions, sea ice cover, and coarse resolution ice thickness using a combined L-band microwave radiometer ...
    • Snowfall and snow accumulation during the MOSAiC winter and spring seasons 

      Wagner, David N.; Shupe, Matthew D.; Cox, Christopher; Persson, Ola G.; Uttal, Taneil; Frey, Markus M.; Kirchgaessner, Amélie; Schneebeli, Martin; Jaggi, Matthias; MacFarlane, Amy R.; Itkin, Polona; Arndt, Stefanie; Hendricks, Stefan; Krampe, Daniela; Nicolaus, Marcel; Ricker, Robert; Regnery, Julia; Kolabutin, Nikolai; Shimanshuck, Egor; Oggier, Marc; Raphael, Ian; Stroeve, Julienne; Lehning, Michael (Journal article; Tidsskriftartikkel; Peer reviewed, 2022-06-17)
      Data from the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition allowed us to investigate the temporal dynamics of snowfall, snow accumulation and erosion in great detail for almost the whole accumulation season (November 2019 to May 2020). We computed cumulative snow water equivalent (SWE) over the sea ice based on snow depth and density retrievals from a ...
    • Synoptic Variability in Satellite Altimeter-Derived Radar Freeboard of Arctic Sea Ice 

      Nab, Carmen; Mallett, Robbie; Gregory, William; Landy, Jack Christopher; Lawrence, Isobel; Willatt, Rosemary; Stroeve, Julienne; Tsamados, Michel (Journal article; Tidsskriftartikkel; Peer reviewed, 2023-01-09)
      Satellite observations of sea ice freeboard are integral to the estimation of sea ice thickness. It is commonly assumed that radar pulses from satellite-mounted Ku-band altimeters penetrate through the snow and reflect from the snow-ice interface. We would therefore expect a negative correlation between snow accumulation and radar freeboard measurements, as increased snow loading weighs the ice floe ...
    • 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∘. ...