Hostname: page-component-848d4c4894-ttngx Total loading time: 0 Render date: 2024-06-07T20:52:42.395Z Has data issue: false hasContentIssue false

Interference and transmission of spatiotemporally locally forced internal waves in non-uniform stratifications

Published online by Cambridge University Press:  05 March 2019

Rohit Supekar*
Affiliation:
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Thomas Peacock
Affiliation:
Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
*
Email address for correspondence: srohit@mit.edu

Abstract

Studies of the effects of constructive or destructive interference on the transmission of internal waves through non-uniform stratifications have typically been performed for internal wave fields that are spatiotemporally harmonic. To understand the impacts of spatiotemporal localization, we present a theoretical and experimental study of the transmission of two-dimensional internal waves that are generated by a boundary forcing that is localized in both space and time. The model analysis reveals that sufficient localization leads to the disappearance of transmission peaks and troughs that would otherwise be present for a harmonic forcing. The corresponding laboratory experiments that we perform provide clear demonstration of this effect. Based on the group velocity and angle of propagation of the internal waves, a practical criterion that assesses when the transmission peaks or troughs are evident is obtained.

Type
JFM Papers
Copyright
© 2019 Cambridge University Press 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Alford, M. H., MacKinnon, J. A., Simmons, H. L. & Nash, J. D. 2016 Near-inertial internal gravity waves in the ocean. Annu. Rev. Mar. Sci. 8, 95123.Google Scholar
Baines, P. G. & Hoinka, K. P. 1985 Stratified flow over two-dimensional topography in fluid of infinite depth: a laboratory simulation. J. Atmos. Sci. 42 (15), 16141630.Google Scholar
Bell, T. H. 1975 Lee waves in stratified flows with simple harmonic time-dependence. J. Fluid Mech. 67, 705722.Google Scholar
Cuypers, Y., Le Vaillant, X., Bouruet-Aubertot, P., Vialard, J. & McPhaden, M. J. 2013 Tropical storm-induced near-inertial internal waves during the Cirene experiment: energy fluxes and impact on vertical mixing. J. Geophys. Res. Oceans 118 (1), 358380.Google Scholar
Echeverri, P. M.2009 Internal tide generation by tall ocean ridges. PhD thesis, Massachusetts Institute of Technology, Cambridge, MA.Google Scholar
Ghaemsaidi, S. J.2015 Interference and resonance of internal gravity waves. PhD thesis, Massachusetts Institute of Technology, Cambridge, MA.Google Scholar
Ghaemsaidi, S. J., Dosser, H. V., Rainville, L. & Peacock, T. 2016a The impact of multiple layering on internal wave transmission. J. Fluid Mech. 789, 617629.Google Scholar
Ghaemsaidi, S. J., Joubaud, S., Dauxois, T., Odier, P. & Peacock, T. 2016b Nonlinear internal wave penetration via parametric subharmonic instability. Phys. Fluids 28 (1), 011703.Google Scholar
Gill, A. E. 1984 On the behavior of internal waves in the wakes of storms. J. Phys. Oceanogr. 14 (7), 11291151.Google Scholar
Gostiaux, L., Didelle, H., Mercier, S. & Dauxois, T. 2007 A novel internal waves generator. Exp. Fluids 42 (1), 123130.Google Scholar
Gregory, K. D. & Sutherland, B. R. 2010 Transmission and reflection of internal wave beams. Phys. Fluids 22 (10), 106601.Google Scholar
Kundu, P. K. 1993 On internal waves generated by travelling wind. J. Fluid Mech. 254, 529559.Google Scholar
Mathur, M. & Peacock, T. 2009 Internal wave beam propagation in non-uniform stratifications. J. Fluid Mech. 639, 133152.Google Scholar
Mathur, M. & Peacock, T. 2010 Internal wave interferometry. Phys. Rev. Lett. 104, 118501.Google Scholar
Mercier, M. J., Martinand, D., Mathur, M., Gostiaux, L., Peacock, T. & Dauxois, T. 2010 New wave generation. J. Fluid Mech. 657, 308334.Google Scholar
Nault, J. T. & Sutherland, B. R. 2007 Internal wave transmission in nonuniform flows. Phys. Fluids 19 (1), 016601.Google Scholar
Oster, G. 1965 Density gradients. Sci. Am. 213 (2), 7076.Google Scholar
Price, J. F. 1981 Upper ocean response to a hurricane. J. Phys. Oceanogr. 11, 153175.Google Scholar
Price, J. F. 1983 Internal wave wake of a moving storm. Part I. Scales, energy budget and observations. J. Phys. Oceonogr. 13, 949965.Google Scholar
Rayson, M. D., Ivey, G. N., Jones, N. L., Lowe, R. J., Wake, G. W. & McConochie, J. D. 2015 Near-inertial ocean response to tropical cyclone forcing on the Australian North-West Shelf. J. Geophys. Res. Oceans 120 (12), 77227751.Google Scholar
Supekar, R. B.2017 Interference and transmission of locally forced internal waves in non-uniform stratifications. Master’s thesis, Massachusetts Institute of Technology, Cambridge, MA.Google Scholar
Sutherland, B. R. 2010 Internal Gravity Waves. Cambridge University Press.Google Scholar
Sutherland, B. R. 2016 Internal wave transmission through a thermohaline staircase. Phys. Rev. Fluids 1 (1), 013701.Google Scholar
Sutherland, B. R. & Yewchuk, K. 2004 Internal wave tunnelling. J. Fluid Mech. 511, 125134.Google Scholar
Timmermans, M.-L., Toole, J., Krishfield, R. & Winsor, P. 2008 Ice-tethered profiler observations of the double-diffusive staircase in the Canada Basin thermocline. J. Geophys. Res. 113, C00A02.Google Scholar
Vailard, J., Duvel, J. P., McPhaden, M. J., Bouruet-Aubertot, P., Ward, B., Key, E., Bourras, D., Weller, R., Minnett, P., Weill, A. et al. 2009 Cirene: air–sea interactions in the Seychelles-Chagos thermocline ridge region. Bull. Am. Meteorol. Soc. 90 (1), 4561.Google Scholar