Seasonal evolution and salt/freshwater fluxes of first-year sea ice: Comparison between pack ice and landfast sea ice
- 1International Arctic Research Center, University of Alaska Fairbanks, Fairbanks, United States of America
- 2Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
- 3Norwegian Polar Institute, Tromsø, Norway
- 4NASA Goddard Space Flight Center, Greenbelt, USA
- 5University of Maryland, College Park, USA
- 6Geophysical institute, University of Alaska Fairbanks, Fairbanks, United States of America
- 7Norwegian University of Science and Technology, Trondheim, Norway
- *A full list of authors appears at the end of the abstract
Sea ice affects the exchange of energy and matter between the atmosphere and the ocean from local to hemispheric scales. Salt fluxes across the ice-ocean interface that drive thermohaline mixing beneath growing sea ice are important elements of upper ocean nutrient and carbon exchange. Sea-ice melt releases freshwater into the upper ocean and results in formation of melt ponds that affect gas and energy transfer across the atmosphere-ice interface. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) provided an opportunity to follow sea-ice evolution and exchange processes over a full seasonal cycle in a rapidly changing ice cover. To this end, approximately 25 sea-ice cores were collected at 2 distinct sites, representing first-year and multi-year ice, to monitor physical, biological and geochemical processes relevant to atmosphere-ice-ocean exchange processes. Here we compare the growth and decay of first-year ice in the Central Arctic during the winter 2019-2020 to that of landfast first-year ice at Utqiaġvik, Alaska, from 1998 to 2016. Ice stratigraphy was similar at both sites with about 15 cm of granular ice on top of columnar ice, with a comparable growth history with a similar maximum ice thickness of 1.6-1.7 m. We aggregated the sea-ice bulk salinity and temperature profiles using a degree-day approach, and examined brine and freshwater fluxes at lower and upper interfaces of the ice, respectively. Preliminary results show lower sea-ice bulk salinity during the growth season and greater desalination at the ice surface during the melt season at the MOSAiC floe in comparison to Utqiaġvik.
Michael Angelopoulos, AWI; Dorothea Bauch, GEOMAR; Jeff Bowman, SCRIPPS; Deborah Bozzato, U Groningen; Giulia Castellani, AWI; Emelia Chamberlain, SCRIPPS; Jessie Creamean, CSU; Ellen Damm, AWI; Adela Dumitrascu, UniTBv; Ulrike Dietrich, AWI; Jessie Gardner, UiT; Rolf Gradinger, UiT; Jari Haapala, FMI; Knut V. Høyland, NTNU, UNIS; Antonnia Immerz, AWI; Nikolai Kolabutin, AARI; Benjamin A. Lange, NPI; Ruibo Lei, PRIC; Brice Loose, URI; Sonke Maus, NTNU; Chris Marsay, UGA; Marcel Nicolaus, AWI; Oliver Müller, UiB; Daiki Nomura, Hokkaido Uni.; Alexey Nuibom, AARI; Lasse Olsen, UiB; Annette Rinke, AWI; Susanne Spahic, AWI; Igor Sheykin, AARI; Egor Shimanchuk, AARI; Patric Simões Pereira, U Gothenburg; Jian Ren, SIO; Jacqueline Stefels, U Groningen; Linda Thielke, Uni Bremen; Anders Torstensson, U Uppsala; Sinhué Torres-Valdés, AWI; Adam Ulfsbo, U Gothenburg; Maria Josefa Verdugo, AWI; Lei Wang, BMU; Alison Webb, U. Warwick; Melinda Webster, UAF; Laura Wischnewski, AWI
How to cite: Oggier, M., Eicken, H., Rember, R., Fong, A., Divine, D. V., Fons, S., Granskog, M. A., Mahoney, A. R., and Salganik, E. and the MOSAiC Sea-Ice Coring Team: Seasonal evolution and salt/freshwater fluxes of first-year sea ice: Comparison between pack ice and landfast sea ice , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10798, https://doi.org/10.5194/egusphere-egu21-10798, 2021.
