A numerical simulation of the generation and evolution of nonlinear internal waves across the Kara Strait

• Published in: Acta oceanologica Sinica Vol. 38; no. 5; pp. 1 - 9
• Main Authors: Li, Qun, Wu, Huiding, Yang, Hongwei, Zhang, Zhanhai
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society of Oceanography 01.05.2019; Springer Nature B.V; Polar Research Institute of China, Ministry of Natural Resources, Shanghai 200136, China%College of Mathematics and Systems Science, Shandong University of Science and Technology, Qingdao 266590, China
• Subjects: Climatology; Computer simulation; Distance; Earth and Environmental Science; Earth Sciences; Ecology; Engineering Fluid Dynamics; Environmental Chemistry; Evolution; Freezing; Ice; Internal waves; Marine & Freshwater Sciences; Mathematical models; Numerical models; Numerical simulations; Oceanography; Packets (communication); Phase velocity; Pycnocline; Pycnoclines; R&D; Research & development; Salinity; Salvage; Satellite data; Sea ice; Simulation; Solitary waves; Straits; Stratification; Summer; Tidal bores; Tides; Topography; Topography (geology); Water depth; Wave packets; Wave trains; Waves; Barents Sea; Kara Sea; nonlinear internal wave; synthetic aperture radar; nonhydrostatic numerical model; Kara Sea
• ISSN: 0253-505X; 1869-1099
• DOI: 10.1007/s13131-019-1437-z

Nonlinear internal waves (NIWs) are ubiquitous around the Kara Sea, a part of the Arctic Ocean that is north of Siberia. Three hot spot sources for internal waves, one of which is the Kara Strait, have been identified based on Envisat ASAR. The generation and evolution of the NIWs through the interactions of the tide and topography across the strait is studied based on a nonhydrostatic numerical model. The model captures most wave characteristics shown by satellite data. A typical inter-packets distance on the Barents Sea side is about 25 km in summer, with a phase speed about 0.65 m/s. A northward background current may intensify the accumulation of energy during generation, but it has little influence on the other properties of the generated waves. The single internal solitary wave (ISW) structure is a special phenomenon that follows major wave trains, with a distance about 5–8 km. This wave is generated with the leading wave packets during the same tidal period. When a steady current toward the Kara Sea is included, the basic generation process is similar, but the waves toward the Kara Sea weaken and display an internal bore-like structure with smaller amplitude than in the control experiment. In winter, due to the growth of sea ice, stratification across the Kara Strait is mainly determined by the salinity, with an almost uniform temperature close to freezing. A pycnocline deepens near the middle of the water depth (Barents Sea side), and the NIWs process is not as important as the NIWs process in summer. There is no fission process during the simulation.