Numerical modeling on landfast ice in the Arctic

• Main Authors: Liu, Yuqing, Losch, Martin
• Format: Conference Object
• Language: unknown
• Published: 2021
• Subjects: Arctic; Arctic Ocean; Climate change; Sea ice
• Online Access: https://epic.awi.de/id/eprint/56437/; https://epic.awi.de/id/eprint/56437/1/poster.pdf; https://hdl.handle.net/10013/epic.ae0d0c3c-c827-4ddc-a692-dfa038a28551

Sea ice is regarded as a clear indicator of climate change in the Arctic Ocean. Landfast ice is immobile or nearly immobile sea ice in coastal regions that affects the transfer of heat, moisture, and momentum between the atmosphere and the ocean. As an extension of the land for travel and hunting, landfast ice also determines the construction of ice roads and Arctic shipping routes in the summertime. Despite the important role of landfast ice in the climate system, landfast ice is not simulated very well by current sea ice models and needs to be parameterized, for example, by a grounding scheme. Comparing landfast ice in two sea-ice simulations with different grid resolutions indicates that a higher resolution model better presents landfast ice in deep water regions, where a grounding scheme fails. The better representation of coastline details, which serve as pinning points for sea ice arches in the high-resolution model, is thought to improve the representation of landfast ice. Based on this hypothesis, a new parameterization of lateral drag as a function of sea ice thickness, drift velocity, and coastline length is presented. The results suggest that a combination of lateral drag parameterization and grounding (parameterized by basal stress) is required to simulate fast ice in most regions successfully. This work may lead to a versatile landfast ice parameterization for sea ice models in both shallow and deep coastal areas in the Arctic.