Ocean Science (Mar 2016)

On the near-inertial variations of meridional overturning circulation in the South China Sea

  • J. Xiao,
  • Q. Xie,
  • D. Wang,
  • L. Yang,
  • Y. Shu,
  • C. Liu,
  • J. Chen,
  • J. Yao,
  • G. Chen

DOI
https://doi.org/10.5194/os-12-335-2016
Journal volume & issue
Vol. 12, no. 1
pp. 335 – 344

Abstract

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We examine near-inertial variability of the meridional overturning circulation in the South China Sea (SCSMOC) using a global 1 / 12° ocean reanalysis. Based on wavelet analysis and power spectrum, we suggest that deep SCSMOC has a significant near-inertial band. The maximum amplitude of the near-inertial signal in the SCSMOC is nearly 4 Sv. The spatial structure of the signal features regularly alternating counterclockwise and clockwise overturning cells. It is also found that the near-inertial signal of SCSMOC mainly originates from the region near the Luzon Strait and propagates equatorward at a speed of 1–3 m s−1. Further analyses suggest that the near-inertial signal in the SCSMOC is triggered by high-frequency wind variability near the Luzon Strait, where geostrophic shear always exists due to Kuroshio intrusion.