wersja polska
Dr Agnieszka Herman
Institute of Oceanography
University of Gdañsk
Al. Pi³sudskiego 46, 81-378 Gdynia
Email: oceagah@ug.edu.pl
Phone: +48 (0)58 5236887
Fax: +48 (0)58 5236678
Curriculum Vitae
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Discrete-element sea ice modeling – development of theoretical and numerical methods

Polish National Science Centre project No. 2015/19/B/ST10/01568 ("OPUS 10" Programme)

Basic information

Project objectives

The subject of the project is sea ice dynamics, especially dynamics of strongly fragmented sea ice and processes leading to ice fragmentation, as well as sub-mesoscale interactions of the sea ice cover with the ocean and the atmosphere. The main project objectives are:
  1. To improve existing and to develop new mathematical models of sea ice–waves interactions suitable for further implementation in discrete-element models, i.e., consistent with underlying concepts of these models.
  2. To formulate, based on the theoretical results, numerical ice–waves interaction algorithms, and to implement these algorithms in the code of the Discrete-Element bonded-particle Sea Ice model (DESIgn; see model homepage).
  3. To verify a hypothesis that: (i) wave-induced breaking tends to produce narrow floe-size distributions (FSD) and polygonal floe shapes and (ii) that further “grinding” of ice floes by shearing deformation in the inner parts of the marginal ice zone is responsible for the observed heavy-tailed FSDs and rounded floe shapes.
  4. To extend the range of applicability of the DESIgn model by developing and implementing parametrization schemes for selected physical processes (e.g., pressure ridging; freezing and melting). Also, to add new functionalities that will facilitate further development and novel applications of the model.
  5. To improve our understanding of factors that may lead to rapid fragmentation of the sea ice cover over large domains, similar to the dramatic break-up event that took place in the Beaufort Sea in winter 2013.
  6. To use high-resolution numerical modeling to improve our understanding of the atmosphere–sea ice–ocean interactions in situations with fragmented sea ice and/or close to the ice edge. To analyze the influence of FSD on heat and momentum fluxes at the sea surface, turbulence, mixing and vertical stability in the tropospheric and oceanic boundary layers. Also, to verify existing hypotheses of ice-band formation close to the ice edge.
  7. To develop parameterizations of the above-mentioned effects, taking into account the floe-size distribution, suitable for future implementation in continuum sea ice models.
A full description of the project can be found here.
A short popular-science summary is here.

Project outcomes

Wenta, M., Herman, A., 2017. Submesoscale atmospheric boundary layer processes over fragmented sea ice, 97th AMS Annual Meeting, 14th Conference on Polar Meteorology and Oceanography, Seattle, USA, 22-26 I 2017 (poster).

Herman, A., 2017. Wave-induced stress and breaking of sea ice in a coupled hydrodynamic–discrete-element wave–ice model. The Cryosphere Discuss., doi: 10.5194/tc-2017-95 (paper).