倒置式回声仪对日本以南海域海面高度变化的反演及其与卫星高度计的比较

Estimation of the sea surface height anomaly south of Japan from Pressure-recording inverted echo sounders and its comparison with the satellite altimeter

倒置式回声仪(PIES)能够观测从海底到海面的声往返传播时间(τ)和海底压力(Pbot),通过τ和Pbot可以反演得到海面高度异常的斜压部分和正压部分。本文首先对日本以南海域的10台PIES进行了海面高度异常的斜压部分和正压部分的反演;其次,我们将卫星高度计的沿轨和网格化的海面高度异常(SLA)与日本以南黑潮海域的6台PIES反演的海面高度异常相比较,比较的结果都呈现较高的相关系数(0.81)。PIES反演的正压部分相对斜压部分较小,加入正压部分对卫星高度计与PIES的比较结果都有一定的改善。海面高度异常波动(<20 d)最高的站位和相关系数最低的站位相一致。

The pressure-recording inversion echo(PIES) could measure round-trip acoustic travel time from the sea floor to the sea surface(τ) and bottom pressure(Pbot), the τ and Pbot measurements are used to estimate the baroclinic and barotropic components of sea level height anomaly, respectively. In this paper, the estimate of baroclinic and barotropic components of sea level height anomalies is performed for 10 PIES in the sea area south of Japan. Secondly, we compared the along-track and gridded sea level anomaly(SLA) of the satellite altimeter with the sea surface height anomaly estimated by six PIES in the Kuroshio area south of Japan, and the results of the comparison reveal a high correlation coefficient(0.81). The barotropic component of the PIES estimation is smaller than the baroclinic component. The addition of the barotropic component has a certain improvement on the comparison results of the satellite altimeter and PIES. The station with highest fluctuations of sea level height anomalies(<20 d) are consistent with station with lowest correlation coefficients.