Acoustic propagation analysis with a sound speed feature model in the front area of Kuroshio Extension. (October 2017)

• Record Type: Journal Article
• Authors: Chen, Cheng; Yang, Kunde; Duan, Rui; Ma, Yuanliang
• Is Part Of: Applied ocean research. Volume 68(2017)
• Page Start: 1
• Page End: 10
• Publication Date: 2017-10
• Subjects: Kuroshio Extension Front -- Sound speed feature model -- Acoustic propagation -- Sea surface height data; Ocean engineering -- Periodicals; 620.416205
• DOI: 10.1016/j.apor.2017.08.001
• Languages: English
• ISSNs: 0141-1187

Abstract

Graphical abstract: Highlights: A 2D sound speed feature model (SSPFM) characterizing the KEF is proposed. The presence of KEF mainly influences acoustic propagation by changing the depth of sound channel. With the SSH to locate the KEF, the 2D SSPFM can provide a near-real-time estimate of the 3D acoustic environment. Abstract: This paper aims to analyse acoustic-propagation character in the front area of Kuroshio Extension (KE). By analysing Argo data and the Sea surface height (SSH) data in this KEF area, a two-dimensional (2D) sound-speed feature model (SSPFM) characterising the KEF is proposed. The SSPFM has a transition zone with a width about 100 km and the sound channel changes from 1000 m south of KEF to 300 m north of KEF, resulting in a sharp gradient about 7 m/km. Along with the meandering character of the KEF axis, the sharp gradient results in a rather complicated acoustic environment in the KEF area. With reanalysis data from the hybrid coordinate ocean model, a three-dimensional (3D) sound-speed environment is established. The acoustic propagation character in the KEF area is then analysed with the 2D SSPFM and the 3D acoustic environment. Results show that the KEF affects acoustic propagation mainly by modifying the sound channel depth. Given that acoustic propagation in the KEF area is influenced mainly by the meandering KEF, with the near-real-time SSH data to locate the KEF, the 2D SSPFM is able to provide a near-real-time estimate of the underwater 3D acoustic environment.