Mode 2 Internal Wave Generation and Propagation Near the New Jersey (USA) Shelf Break -Early Fall Season

Abstract : Mode 2 internal waves have been repeatedly observed in two separate bathymetry zones on the New Jersey (USA) continental shelf. In the first zone, the upslope propagating mode 2 internal waves were detected in a 15 km range interval shoreward of the shelf break in water depths ranging between 90 and 150 m. They were formed in conjunction with shoreward propagating internal tides and exhibited both nonlinear and linear characteristics. In the second zone, they were detected in 60 to 80 m water depths and appeared to be formed by flow over the local bathymetry. Simulations using the Shen Non-hydrostatic Model for Coastal Oceans (SNMCO) replicated the observed coupled internal tide and mode 2 internal wave generation process and separately the formation of mode 2 internal waves by flow over local bathymetry variability. The observations expand the knowledge base regarding the time window (fall, 7 days before and including neap tidal conditions), spatial distributions, packet evolution and conditions under which mode 2 internal waves are generated on the continental shelf.