Improving mesoscale observations from satellite altimetry using bottom pressure and tide gauge measurements in the Japan Sea

Abstract

ABSTRACTIn the Japan/East Sea (Sea of Japan), the basin-scale barotropic high-frequency signals cause aliasing error in the gridded sea level anomaly (SLA) product of the satellite altimeters. The aliasing errors can produce false mesoscale eddies and alter the dynamical explanation of ocean circulation. In this article, we corrected non-tidal aliasing errors in gridded SLA product using bottom pressure (BP) data and tide gauge (TG) data. The root mean square (RMS) of the aliasing induced SLA is about 3 cm in the Sea of Japan, which accounts for about 20% of the total energy. We found that, after BP correction, the percentage of error variance (PEV) is reduced from 43% to 34% for satellite-derived velocity, and from 22% to14% for 70-day low-pass filtered gridded SLA product. However, the improvement for TG correction is not notable. The basin-scale barotropic high-frequency signals are likely to be found in other nearly enclosed marginal seas. We suggested that more BP measurements should be conducted in the marginal seas for aliasing correction. The work in this article offers a useful reference for suppressing non-tidal alias errors in other marginal seas.