Author(s): Dingyi Ma; Yuxiang Zhang; Zhinan Xie; Jiahui Gao; Xueli Sheng
Linked Author(s):
Keywords: Sea Ice; Advances in Ice Numerical Modelling
Abstract: The rapidly changing Arctic region has now drawn more attention than ever. The uniqueness of the Arctic comes from its ice-cover which constitutes one-of-a-kind propagation media for elastic waves, while the acoustic/seismic methods have been widely applied for the study or observation of sea ice. The propagation of elastic waves within sea-ice is governed by waveguide, a new waveguide model is thus proposed here in this manuscript for a more realistic description of the propagation feature in sea ice. In previously reported models, the sea ice is usually regarded as a homogeneous elastic plate. However, the elastic feature of sea-ice exhibits a complex vertical profile mainly due to the presence of salinity variation and the temperature contrast at its surfaces. Having the propagation velocity profile modeled based on the vertical variation of temperature and salinity, a theoretical model is proposed based on the Spectral Element Method (SEM). The corresponding characteristic equations are then solved numerically within complex space to take into account the energy leakage. The dispersive and the multi-modal characteristics of the leaky waveguide of sea ice are then obtained and compared to numerical simulation results for verification and further discussion regarding the transmission of acoustic energy through a water-ice coupled system. Finally, the proposed modal is also compared with that of a homogeneous elastic plate to discuss the necessity of taking the internal temperature and salinity gradients into account in the modeling of sea ice.
Year: 2022