Nontraditional baroclinic wave effects in the Strait of Gibraltar

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General wave theory suggests that baroclinic bores produced by a barotropic tide over bottom topography and propagated from the source of generation, disintegrate into a system of well rank-ordered internal waves packet. However, the majority of observational data collected in the Strait of Gibraltar by the University of Malaga during the three-month measurements at moorings located in the middle of the strait and beyond it (50 km off the strait in the Alboran Sea) doesn't support this idea. Less than 40% of all registered wave packets demonstrated the rank-ordered structure, whereas the rest of wave packets were clearly non-rank ordered. An evident contradiction between the up-to-date understanding of the wave process and observational evidence is a big challenge and strong motivation of the present study. It is important to make clear bearing in mind the great role which mixing processes initiated by tidally generated internal waves play both for regional ecological situation in the strait and adjacent areas and for the formation of the Deep Mediterranean Waters on a global scale. It is hypothesized in the project that the irregular structure of the observed packets is a manifestation of a more general mechanism of interaction of propagating along the channel large-amplitude internal waves with its lateral boundaries where extensive wave breaking, water mixing, wave refraction and reflection take place. Being repeated many times in every wave packet, these processes produce a complex spatial wave structure in which wave energy can transform both from wave to wave and sink to turbulence. Thus, the present proposal is intended to fill the gap in understanding of the not studied yet mechanism of the three-dimensional evolution of large-amplitude internal waves in the strait. As distinct from many previous theoretical studies which exploited the two-dimensional idea or the hydrostatic approximation for pressure and excluded the effects related to non-hydrostatic internal mixing, this project is aimed to apply a three-dimensiona fully-nonlinear nonhydrostatic numerical model and in combination with observational data to describe and quantify dynamical processes in the strait related to propagation of large amplitude internal waves. The achievement of the project goals is based on the the use of detailed observational data set collected in the Strait of Gibraltar and application of the state-of-the art the Massachusetts Institute of Technology general circulation model.