겨울철의 남중국해 내부조석파

Abstract

In Luzon Strait, strong tidal currents interact with submarine ridges to generate westward propagating internal waves of large amplitude and also the Kuroshio flows across with variable strength and direction. This study describes observations of these internal waves acquired in the deep basin of the northeastern South China Sea using pressure-recording inverted echo sounders during the winter of 2010&#8211 2011, with the goal of assessing the influence of meso-scale variability on their properties. The HYCOM predicts Kuroshio penetration across Luzon Strait during our observations. We find that horizontal stratification gradients and vertical shear provide weak predictions of internal wave amplitude modulation. Deviations in internal wave arrival time derived from integration of their first-mode phase speed along 2-dimensional ray-traced paths are quite well predicted, with wave arrivals occurring up to about 2 hours early during Kuroshio intrusion periods, consistent with the observations. Our results suggest that the internal wave field can be a sensitive indicator of meso-scale variability in Luzon Strait and the northeastern South China Sea.ons of these internal waves acquired in the deep basin of the northeastern South China Sea using pressure-recording inverted echo sounders during the winter of 2010&#8211 2011, with the goal of assessing the influence of meso-scale variability on their properties. The HYCOM predicts Kuroshio penetration across Luzon Strait during our observations. We find that horizontal stratification gradients and vertical shear provide weak predictions of internal wave amplitude modulation. Deviations in internal wave arrival time derived from integration of their first-mode phase speed along 2-dimensional ray-traced paths are quite well predicted, with wave arrivals occurring up to about 2 hours early during Kuroshio intrusion periods, consistent with the observations. Our results suggest that the internal wave field can be a sensitive indicator of meso-scale variability in Luzon Strait and the northeastern South China Sea.