| Based on the seasonal average data of WOA13 and the BELLHOP model, this paper analyzes the acoustic waveguide in the eastern and western parts of North Atlantic Ocean respectively in winter by dividing the surface sound source of 10 m and underwater sound source of 250 m, in the case of fixed seasonal, sound source frequency and other factors. This paper aims to derive the laws based on the given information of sound speed field and acoustic waveguide of different sea areas: The minimum sound speed and axial sound channel in the Gibraltar Strait diminish outward and spread and diffuse, with the surface sound speed and speed velocity gradient descending from the south to north. The sound speed thermocline exists in low latitude areas, the mixed layer is usually within 100 m in low latitudes, and increases to more than 100 m in high latitudes. The inversion depth of convergence zone for 10 m surface sound source gradually decreases with the increase of latitude, and the western sea areas is deeper than the eastern area. The convergence zone span of western sea areas is greater than eastern, with the maximum span of eastern at 25 °N, and western at 15 °N, and transmission losses being basically identical. The inversion depth of convergence zone for 250 m underwater sound source is shallower than the depth for 10 m surface sound source. Besides, the value in western sea areas is greater than that in the eastern. The span of convergence zone shows a law of low-high-low tendency with changing latitudes, with the maximum span of eastern at 35 °N, and western at 25 °N. The transmission losses in different receiving depths have been greater in the southern areas of 25 °N of eastern areas and 15 °N of western areas, and the losses in northern areas are negligible. In addition, this paper also briefly expounds the influence of acoustic shadow zone on target detection. |
