EGU2020-8086, updated on 12 Jun 2020
https://doi.org/10.5194/egusphere-egu2020-8086
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Evaluation of landfast ice simulations with basal stress parameterization using the Regional Arctic System Model

Jan Niciejewski1, Robert Osinski1, Wieslaw Maslowski2, and Anthony Craig
Jan Niciejewski et al.
  • 1Institute of Oceanology of the Polish Academy of Sciences, Physical Oceanography, Poland (niciejewski@iopan.pl)
  • 2Naval Postgraduate School, Department of Oceanography, Monterey, CA, USA

The landfast ice (LFI) is an important component of the Arctic environment, especially in regions of shallow shelfs North of Alaska and Siberia. Its presence affects the transfer of energy between the atmosphere and the ocean. Its outer edge continuously interacts with the moving pack ice. One of the mechanisms of LFI formation – grounded ice keels, acting as anchor points – was parametrized in the version 6 of Los Alamos sea ice model (CICE) Consortium.  The parametrization is based on the bathymetry data, ice concentration and the mean ice thickness in a grid cell. It enables determination of the critical thickness, required for large ice keels to reach the bottom and calculation of the basal stress. A series of experiments using the Regional Arctic System Model (RASM) with CICEv6 has been conducted. In addition to sea ice model, RASM includes the atmosphere (WRF), ocean (POP), land hydrology (VIC), and river routing scheme (RVIC) components controlled by a flux coupler (CPL). LFI simulations using two different rheologies: elastic-visous-plast (EVP) and elastic-anisotropic-plastic (EAP) have been evaluated in the fully coupled and forced sea ice - ocean configurations.  Also, sensitivity studies with varying values of the LFI free parameters have been performed. Results are compared against landfast ice extent data from the National Snow & Ice Data Center. In the optimal configuration, including the basal stress parameterization, the model reproduces observed landfast ice in East Siberian, Laptev Sea, and along the coast of Alaska. However, some areas continue to be problematic – like the Kara Sea where LFI is underestimated and the area around the New Siberian Islands, where landfast ice growth is too high. In the former case, the ice arching might be the major landfast ice formation mechanism there, whereas in the latter case the model internal stress distribution might not be adequate to allow realistic sea ice drift between the islands.

How to cite: Niciejewski, J., Osinski, R., Maslowski, W., and Craig, A.: Evaluation of landfast ice simulations with basal stress parameterization using the Regional Arctic System Model, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-8086, https://doi.org/10.5194/egusphere-egu2020-8086, 2020