Estimate method for frontal position of Kuroshio extension using ocean acoustic tomography data

Abstract

In the present study, a simple and efficient method for estimating frontal positions of the Kuroshio extension (KE) is proposed using relationship between meridional shifts of the KE and acoustic travel time propagating through the SOFAR channel. Effectiveness of the proposed method is estimated by sound propagation simulation using the temperature and salinity fields from observations in the KE, and demonstrates propriety of this method. Applying this method to in situ ocean acoustic tomography data in the KE region in summer 1997 provides the proper estimates of the KE positions. This simple method may be utilized in determining “initial guess of the KE position” and “reference sound speed field” that are necessary for ocean acoustic tomographic inversion which is much more complicated and time-consuming data analysis.