[A-OS16] Frontiers of Ocean Mixing Research

[AOS16-02] Numerical simulations of internal solitary wave evolution beneath an ice keel

*Peiwen Zhang¹, Zhenhua Xu¹, Qun Li², Jia You¹, Baoshu Yin¹, Robin Robertson³, Quanan Zheng⁴ (1.CAS Key Laboratory of Ocean Circulation and Waves, Institute of Oceanology, Chinese Academey of Science, 2.MNR Key Laboratory for Polar Science, Polar Research Institute of China, 3.China-Asean College of Marine Science, Xiamen University Malaysia, 4.Department of Atmospheric and Oceanic Science, University of Maryland)

Keywords:Ice keel, Internal solitary wave, MITGCM, mixing

The deformation and evolution of internal solitary waves (ISWs) beneath an ice keel can enable potential diapycnal mixing and facilitate upper ocean heat transport, despite a poor understanding of the underlying physics and energetics of ISWs in Polar environments. This study aims to understand the dynamic processes and mixing properties during the evolution of ISWs beneath ice keels in the Arctic Ocean using high-resolution, nonhydrostatic simulations. Ice keels can destabilize ISWs through overturning events. Consequently, the initial ISW disintegrates and transfers its energy into secondary smaller-scale waves. During the ISW-ice interaction, ISW-induced turbulent mixing can reach O(10^-3) W/kg with a magnitude of resultant heat flux of O(10)W/m. Sensitivity experiments demonstrated that the ISW-ice interaction weakened as the ice keel depth decreased, and consequently, the resultant turbulent mixing and upward heat transfer also decreased. The ice keel depth was critical to the evolution and disintegration of an ISW beneath the ice keel, while the approximate ice keel shape had little effect. Our results provide an important but previously overlooked energy source for upper ocean heat transport in the Arctic Ocean.