Mode 2 waves on the continental shelf : ephemeral components of the nonlinear internal wavefield
MetadataShow full item record
Shoreward propagating, mode 2 nonlinear waves appear sporadically in mooring records obtained off the coast of New Jersey in the summer of 2006. Individual mode 2 packets were tracked between two moorings separated by 1 km; however, packets could not be tracked between moorings separated by greater distances from one another (∼10 km). The inability to track individual packets large distances through the mooring array combined with detailed observations from a ship suggest that these waves are short lived. The evolution of the ship-tracked wave group was recorded using acoustic backscatter, acoustic Doppler current profilers, and turbulence profiling. The leading mode 2 wave quickly changed form and developed a tail of short, small-amplitude mode 1 waves. The wavelength of the mode 1 oscillations agreed with that expected for a copropagating tail on the basis of linear theory. Turbulent dissipation in the mixed layer and radiation of the short mode 1 waves contributed to rapid energy loss in the leading mode 2 wave, consistent with the observed decay rate and short life span of only a few hours. The energy in the leading mode 2 wave was 10–100 times smaller than the energy of mode 1 nonlinear internal waves observed during the experiment; however, the magnitudes of wave-localized turbulent dissipation were similar.
Author Posting. © American Geophysical Union, 2010. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 115 (2010): C07001, doi:10.1029/2009JC005605.
Suggested CitationJournal of Geophysical Research 115 (2010): C07001
Showing items related by title, author, creator and subject.
Sharp thermal transition in the forearc mantle wedge as a consequence of nonlinear mantle wedge flow Wada, Ikuko; Rychert, Catherine A.; Wang, Kelin (American Geophysical Union, 2011-07-08)In the forearc mantle wedge, the thermal field depends strongly on slab-driven mantle wedge flow. The flow is in turn affected by the thermal field via the temperature dependence of mantle rheology. Using thermal modeling, ...
Benthuysen, Jessica A. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2010-06)In a stratified rotating fluid, frictionally driven circulations couple with the buoyancy field over sloping topography. Analytical and numerical methods are used to quantify the impact of this coupling on the vertical ...
Thomson, James M.; Elgar, Steve; Raubenheimer, Britt; Herbers, T. H. C.; Guza, R. T. (American Geophysical Union, 2006-03-01)The strong tidal modulation of infragravity (200 to 20 s period) waves observed on the southern California shelf is shown to be the result of nonlinear transfers of energy from these low-frequency long waves to ...