Argo float trajectory data has been used to estimate the velocities of mid-depth (1000 db) currents in the North Indian Ocean (NIO). The structure of the upper ocean absolute geostrophic currents can be derived more accurately from the Argo temperature and salinity profiles by referring to the estimated velocities rather than by assuming a level of “no motion”. The derived flow field reveals that the eastward zonal velocities generate striation-like structures in the Arabian Sea, which is most prominent above the layer of 500 db layer, with a meridional scale of ~300 km; however, such structures are barely observed in the Bay of Bengal. This meridional scale as well as the distribution of the mid-depth striations are unique to the NIO, as compared with the other ocean basins. The nonlinear $1\frac{1}{2}$-layer reduced-gravity model combined with the triad baroclinic Rossby wave interaction theory have been used to determine the essential factors controlling the characteristics of the quasi-zonal striation structure. Compared with the North Pacific Ocean, the meridional scale in the NIO is narrower, and is caused by the smaller basin size in the equatorial zone, rather than by the semiannual wind stress forcing period or the eastern boundary angle. Furthermore, the coastal trapped Kelvin waves significantly contribute to the generation of the zonal striations in the Arabian Sea.

Argo漂浮轨迹数据已用于估算北印度洋（NIO）中深水流（1000 db）的速度。可以通过参考估算的速度而不是假设“不运动”的水平，更准确地从Argo温度和盐度剖面推导出上层海洋绝对地转流的结构。导出的流场揭示出，东纬带速度在阿拉伯海中产生了类似条纹的结构，该结构在500 db层以上最为突出，子午线规模约为300 km。但是，在孟加拉湾几乎没有观察到这种结构。与其他海盆相比，NIO特有的子午线规模以及中深度条纹的分布。非线性$\mathrm{1个}\frac{\mathrm{1个}}{2}$层降重力模型与三重斜压Rossby波相互作用理论相结合，已被用来确定控制准带状横纹构造特征的基本因素。与北太平洋相比，NIO的子午线尺度更窄，它是由赤道带较小的盆地尺寸引起的，而不是由半年的风应力强迫期或东部边界角引起的。此外，沿海被困的开尔文波极大地促进了阿拉伯海地带的产生。