Simulations of low-mode internal tides in realistic mean flows

Thursday, 18 December 2014: 2:00 PM
Samuel Maurice Kelly1,2, Pierre F J Lermusiaux2, Timothy F Duda3 and Patrick J Haley Jr4, (1)University of Minnesota Duluth, Duluth, MN, United States, (2)MIT, Cambridge, MA, United States, (3)Woods Hole Oceanographic Inst, Woods Hole, MA, United States, (4)Massachusetts Institute of Technology, Cambridge, MA, United States
Large-scale internal tides can be modeled as vertical modes that propagate as linear shallow-water waves and are coupled by sloping topography, horizontal density gradients, and background currents. Here, this framework is used to analyze and simulate internal-tide generation, propagation, and scattering in idealized and realistic settings. First, idealized simulations with the Coupled Shallow Water model (CSW) are used to assess the sensitivity of internal-tide generation to horizontal resolution and vertical resolution (i.e., the number of vertical modes). Next, the dynamical effects of background conditions on internal-tide propagation and scattering are analyzed in realistic data-assimilating simulations of the Middle Atlantic Bight, which were conducted with the MSEAS primitive equation model. Lastly, we include linearized advection terms in CSW and simulate large-scale internal-tide interactions with the Gulf Stream in the western North Atlantic. The results provide context for previous observations of incoherent internal tides on the New Jersey continental slope.