WHOI PO

Using four summers/falls of temperature and velocity measurements from a
surface mooring in 100 m of water off the Washington coast, more than 1000
nonlinear internal wave (NLIW) events are detected and analyzed. The largest
wave in the record has an amplitude of 51 m and energy of O(10^7 J/m).
Propagating onshore towards the north-northeast, NLIWs show a variety of
morphologies, but are mostly mode-1 depression waves that arrive semi-diurnally
along with the internal tide (IT). NLIW energy flux is correlated with IT energy
flux but not the barotropic forcing, implying that NLIW arise from shoaling IT
rather than local generation by the barotropic tide. NLIWs with potential of trapped cores
and considerable lateral transport are detected, indicating their possibilities of being an
important mechanism in local cross-shelf transport. Static instabilities several meters high
often accompany NLIWs, suggesting potentials to enhance local mixing and dissipation.