Simulations of low-mode internal tides in realistic mean flows

Abstract:

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.