Keywords:internal tide, Sanriku, shelf-break, nonhydrostatic model
Hydrographic observations made in several bays (e.g. Otsuchi bay, Toni bay) on the Sanriku Coast, Japan, detected that baroclinic circulations extending over the bays intermittently occur (e.g. Okazaki, 1990, 1994; Tanaka et al. 2016). Previous studies suggest that the main source of this baroclinic circulation is the internal tides (Okazaki, 1990, 1994; Otobe et al., 1996, 2009; Ito et al., 1998), however, detailed mechanisms are not clear. In the present study, we perform numerical experiments with a two-dimensional (x-z) nonhydrostatic model (Akitomo et al. 1995) in order to investigate the internal tides along the Sanriku Coast focused on the amplification process of the baroclinic circulation over the bays.
Experimental results (Figure 1) indicate that the internal waves enhance the baroclinic circulations over the bays. This internal waves are generated at the shelf break and propagate to the bay mouth.