We found a match
Your institution may have rights to this item. Sign in to continue.
- Title
Enhanced diapycnal mixing with polarity-reversing internal solitary waves revealed by seismic reflection data.
- Authors
Gong, Yi; Song, Haibin; Zhao, Zhongxiang; Guan, Yongxian; Zhang, Kun; Kuang, Yunyan; Fan, Wenhao
- Abstract
Shoaling internal solitary waves near the Dongsha Atoll in the South China Sea dissipate their energy and enhance diapycnal mixing, which have an important impact on the oceanic environment and primary productivity. The enhanced diapycnal mixing is patchy and instantaneous. Evaluating its spatiotemporal distribution requires comprehensive observation data. Fortunately, seismic oceanography meets the requirements, thanks to its high spatial resolution and large spatial coverage. In this paper, we studied three internal solitary waves in reversing polarity near the Dongsha Atoll and calculated their spatial distribution of diapycnal diffusivity. Our results show that the average diffusivities along three survey lines are 2 orders of magnitude larger than the open-ocean value. The average diffusivity in internal solitary waves with reversing polarity is 3 times that of the non-polarity reversal region. The diapycnal diffusivity is higher at the front of one internal solitary wave and gradually decreases from shallow to deep water in the vertical direction. Our results also indicate that (1) the enhanced diapycnal diffusivity is related to reflection seismic events, (2) convective instability and shear instability may both contribute to the enhanced diapycnal mixing in the polarity-reversing process, and (3) the difference between our results and Richardson-number-dependent turbulence parameterizations is about 2–3 orders of magnitude, but its vertical distribution is almost the same.
- Subjects
INTERNAL waves; SEISMIC waves; SPATIAL resolution; THERMAL instability; MAGNITUDE (Mathematics)
- Publication
Nonlinear Processes in Geophysics, 2021, Vol 28, Issue 3, p445
- ISSN
1023-5809
- Publication type
Article
- DOI
10.5194/npg-28-445-2021