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A New-Generation Internal Tide Model Based on 30 Years of Satellite Sea Surface Height Measurements: Multiwave Decomposition and Isolated Beams
  • Zhongxiang Zhao
Zhongxiang Zhao
University of Washington

Corresponding Author:[email protected]

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Abstract

A new-generation internal tide model ZHAO30yr is constructed using 30 years of sea surface height measurements from 1993 to 2022 made by 15 satellite altimetry missions. The model contains 8 mode-1 constituents (M2, S2, N2, K2, K1, O1, P1 and Q1) and 4 mode-2 constituents (M2, S2, K1 and O1). These constituents are respectively extracted by the same mapping technique that consists of two rounds of plane wave analysis with a spatial bandpass filter in between. Their prerequisite wavelengths are calculated from climatological annual-mean hydrographic profiles in the World Ocean Atlas 2018. Model errors are estimated to be 0.5-1 mm for all semidiurnal and diurnal constituents. The model is evaluated using 1 year of independent altimetry data in 2023. The global internal tide field is decomposed into multiconstituent multimodal multidirectional internal waves. Multiwave decomposition reveals unprecedented new features previously masked by multiwave interference. Numerous long-range internal tidal beams are observed to be associated with notable topographic features. Semidiurnal beams off the Amazon shelf and diurnal beams in the Arabian Sea are studied in detail. The M2 and K1 internal tide constituents are examined for their multiwave decomposition and isolated beams on a global scale.
25 Jul 2024Submitted to ESS Open Archive
25 Jul 2024Published in ESS Open Archive