Satellite Observed Multisource Internal Tide Radiation and Interference in the Banda Sea

Abstract

AbstractBoth the semidiurnal and diurnal internal tides in the Banda Sea were investigated using multi‐satellite altimeter data, through a combination of plane wave analysis technique and two‐dimensional band‐pass spatial filtering. The west and central Banda Sea are found to be dominated by semidiurnal internal tides, while the diurnal internal tides dominate the east. Multiple internal tidal sources were located at or nearby the Banda Arc, radiating significant internal tides inwards in complex interference patterns in the Banda Sea basin. The semidiurnal sources were situated on the northern and southern sides of the Banda Arc, emanating internal tides in opposite meridional directions. The semidiurnal tidal beams then experienced interference, shaping the heterogeneous energy fields in the west and central Banda Sea. The primary diurnal source was situated over the steep slope in the Aru Basin, with significant energy radiation westward and diffraction in the east Banda Sea. Based on the estimation of 27‐year coherent satellite results, the total energy flux of mode‐1 internal tides into the Banda Sea is about 4.82 GW, 58% contributed by semidiurnal tides and 42% by diurnal tides. This study represents the first observed mapping of the complex and inhomogeneous mode‐1 semidiurnal and diurnal internal tidal energy fields over the entire Banda Sea. Furthermore, this study enables further characterization of tidal mixing properties and improvement of model mixing parameterizations in the Indonesian seas.