JpGU-AGU Joint Meeting 2017

Presentation information

[EJ] Oral

A (Atmospheric and Hydrospheric Sciences) » A-OS Ocean Sciences & Ocean Environment

[A-OS29] [EJ] Dynamics of oceanic and atmospheric waves, vortices, and circulations

Tue. May 23, 2017 10:45 AM - 12:15 PM 302 (International Conference Hall 3F)

convener:Ryo Furue(APL/JAMSTEC), Yukiharu Hisaki(Faculty of Science, University of the Ryukyus), Humio Mitsudera(Institute of Low Temperature Science, Hokkaido University), Norihiko Sugimoto(Keio University, Department of Physics), Chairperson:Yukiharu Hisaki(Faculty of Science, University of the Ryukyus), Chairperson:Norihiko Sugimoto(Keio University, Department of Physics), Chairperson:Hideyuki Nakano(Meteorological Research Institute)

11:00 AM - 11:15 AM

[AOS29-08] Generation of internal solitary waves by frontally forced intrusions in geophysical flows

*Daniel Bourgault1, Peter Galbraith2, Chavanne Cédric1 (1.Université du Québec à Rimouski UQAR, 2.Fisheries and Oceans Canada, Maurice Lamontagne Institute)

Keywords:internal solitary waves, front, intrusion

Internal solitary waves are hump-shaped, large-amplitude waves that are physically analogous to surface waves except that they propagate within the fluid, along density steps that typically characterize the layered vertical structure of lakes, oceans and the atmosphere. As do surface waves, internal solitary waves may overturn and break, and the process is thought to provide a globally significant source of turbulent mixing and energy dissipation. Although commonly observed in geophysical fluids, the origins of internal solitary waves remain unclear. Here we report a rarely observed natural case of the birth of internal solitary waves from a frontally forced interfacial gravity current intruding into a two-layer and vertically sheared background environment. The results of the analysis carried out suggest that fronts may represent additional and unexpected sources of internal solitary waves in regions of lakes, oceans and atmospheres that are dynamically similar to the situation examined here in the Saguenay Fjord, Canada.