EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Differential summer melt rates of ridges, first- and second-year ice in the central Arctic Ocean during the MOSAiC expedition

Evgenii Salganik1, Benjamin Lange2, Christian Katlein3, Ilkka Matero3,4, Julia Regnery3, Igor Sheikin5, Philipp Anhaus3, Knut Høyland1, and Mats Granskog2
Evgenii Salganik et al.
  • 1Norwegian University of Science and Technology, Trondheim, Norway
  • 2Norwegian Polar Institute, Fram Centre, Tromsø, Norway
  • 3Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung, Bremerhaven, Germany
  • 4Svalbard Integrated Arctic Earth Observing System Knowledge Centre, Longyearbyen, Svalbard
  • 5Arctic and Antarctic Research Institute, St Petersburg, Russia

During the melt season, sea ice melts from the surface and bottom. The melt rates substantially vary for sea ice ridges and undeformed first- and second-year ice. Ridges generally melt faster than undeformed ice, while the melt of ridge keels is often accompanied by further summer growth of their consolidated layer. This summer consolidation is related to refreezing of less saline meltwater, originating from snowmelt and ridge keel melt. We examine the spatial variability of ice melt for different types of ice from in situ drilling, coring, and from multibeam sonar scans of remotely operated underwater vehicle (ROV). Seven ROV scans, performed from 24 June 2020 to 28 July 2020 during the Multidisciplinary drifting Observatory for the Study of the Arctic Climate (MOSAiC) expedition were analyzed. The area investigated by the ROV (400 by 200 m) consisted of several ice ridges, surrounded by first- and second-year ice. Seven ice drilling transects were additionally performed to validate ROV measurements. The maximum keel depth of the ridge investigated by ice drilling was 6.5 m. We show a substantial difference in melt rates of first-year ice, second-year ice, and sea ice ridge keels. We also show how ridge keels decay depending on keel depth, width, steepness, and orientation relative to the ice drift direction. These results are important for quantifying ocean heat fluxes for different types of ice during advanced melt, and for estimation of the ridge contribution to the total ice mass and summer meltwater balances of the Arctic Ocean.

How to cite: Salganik, E., Lange, B., Katlein, C., Matero, I., Regnery, J., Sheikin, I., Anhaus, P., Høyland, K., and Granskog, M.: Differential summer melt rates of ridges, first- and second-year ice in the central Arctic Ocean during the MOSAiC expedition, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11518,, 2022.


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