EGU21-3757, updated on 04 Mar 2021
https://doi.org/10.5194/egusphere-egu21-3757
EGU General Assembly 2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Manual point-measurements of sea ice mass balance during the MOSAiC Expedition

Ian Raphael1, Donald Perovich1, Chris Polashenski1,2, David Clemens-Sewall1, Polona Itkin3,4, Matthias Jaggi5, Julia Regnery6, Madison Smith7, Jennifer Hutchings8, Marcel Nicolaus6, Ilkka Matero6, David Wagner5, Marc Oggier9, Oguz Demir10, Amy Macfarlane5, and Steven Fons11
Ian Raphael et al.
  • 1Dartmouth College, Thayer School of Engineering, Hanover, NH, United States (ian.a.raphael.th@dartmouth.edu)
  • 2USACE-CRREL, Alaska Projects Office, Ft. Wainwright, AK, United States
  • 3UiT The Arctic University of Norway, Tromsø, Norway
  • 4Colorado State University, Cooperative Institute for Research in the Atmosphere (CIRA), Fort Collins, CO, United States
  • 5WSL Institute for Snow and Avalanche Research SLF, Davos Dorf, Switzerland
  • 6Alfred Wegener Institute Helmholtz-Center for Polar and Marine Research, Bremerhaven, Germany
  • 7Applied Physics Laboratory, University of Washington, Seattle, WA, United States
  • 8Oregon State University, Corvallis, OR, United States
  • 9University of Alaska Fairbanks, International Arctic Research Center, Fairbanks, AK, United States
  • 10Ohio State University Main Campus, Department of Electrical and Computer Engineering, Columbus, OH, United States
  • 11NASA Goddard Space Flight Center, Greenbelt, MD, United States

Sea ice plays a critical role in the Arctic climate system, regulating much of the energy transfer between the ocean and the atmosphere. Repeat measurements of ice mass balance at discrete points allow us to determine the direct response of sea ice mass to environmental conditions. We installed a network of mass balance measurement sites across the MOSAiC Central Observatories, distributed over a diverse range of ice types and features. The sites were composed of gridded arrays of 9-17 hotwire thickness gauges, each paired with a surface ablation stake. Seven sites were installed on first year ice, and seven on second or multi year ice, with a total of 120+ individual measurement stations. The sites were operational over different periods throughout the year; several were destroyed or became inaccessible during ridging events. Initial ice thicknesses ranged from 0.13-3.50 m. We made measurements of ice and snow interfaces and thicknesses with 1 cm precision at each station, at intervals of 2-3 weeks during the growth season and as few as 1-2 days during the melt season. From these measurements, we infer ice growth, ice bottom melt, ice surface melt, snow deposition, snow erosion, and snow melt. The time series spans October 2019–September 2020, with a five-week measurement gap beginning mid-May 2020. We present an overview of the measurements and preliminary analysis, partitioning results by ice type and comparing mass balance to concurrent atmosphere and ocean measurements. We identify trends in the seasonal evolution of different ice types, and give particular attention to notable events in the time series. As true point-measurements, the data are especially relevant in improving one-dimensional thermodynamic sea ice models. The results also provide validation for satellite and electromagnetic induction ice-thickness measurements made during MOSAiC, which offer higher areal coverage but lower measurement- and spatial-precision.

How to cite: Raphael, I., Perovich, D., Polashenski, C., Clemens-Sewall, D., Itkin, P., Jaggi, M., Regnery, J., Smith, M., Hutchings, J., Nicolaus, M., Matero, I., Wagner, D., Oggier, M., Demir, O., Macfarlane, A., and Fons, S.: Manual point-measurements of sea ice mass balance during the MOSAiC Expedition, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3757, https://doi.org/10.5194/egusphere-egu21-3757, 2021.

Corresponding presentation materials formerly uploaded have been withdrawn.