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本研究从卫星遥感信息入手,对出现在西部边界流与陆坡水之间边界上的切变波动态过程进行了观测与动力学分析,由NOAA卫星红外图像测得的哈特勒斯(Hatteras)角以东,湾流北侧的切变波平均波长为75 km,平均波幅(波峰至波谷)为17 km,平均相速度为100 cm/s,黑潮北侧的切变波平均波长为57 km,平均波幅为17 km,由Seasat-1合成孔径雷达(SAR)图像测得的哈特勒斯角以南,湾流西侧的切变波平均波长为131 km,平均波幅为33 km,一次切变波事件的持续时间约为一周。 为探讨切变波的动力机制,我们求解了层化流体的涡度方程,得出了切变波频散关系的解析表达式,结果表明,切变波相速度与波长成抛物线关系;平均流场是频散关系中的重要因子,后一点表明流速水平切向变化是切变波发生的基本条件,理论分析为卫星遥感数据所证实。
Based on the satellite remote sensing information, this study observes and dynamics analyzes the shear wave dynamics occurring at the boundary between the western border flow and the slope water. The Hatteras measured by the NOAA satellite infrared image, To the east of the angle, the average wavelength of the shear wave on the north side of the Gulfstream is 75 km, the average amplitude (crest to trough) is 17 km, the average phase velocity is 100 cm / s, and the average wavelength of the shear wave on the north side of Kuroshio is 57 km , With an average amplitude of 17 km. To the south of Hathawos angle measured by the Seasat-1 Synthetic Aperture Radar (SAR) image, the average wavelength of the shear wave on the west side of the Gulfstream is 131 km and the average amplitude is 33 km. Wave events last about one week. In order to investigate the dynamic mechanism of shear wave, we solved the vorticity equation of stratified fluid, and obtained the analytical expression of the dispersion relation of shear wave. The results show that the shear wave phase velocity has a parabolic relationship with the wavelength; mean flow The field is an important factor in the dispersion relation. The latter shows that the horizontal tangential variation of the flow velocity is the basic condition for the shear wave to occur. The theoretical analysis is confirmed by the satellite remote sensing data.