The Xiamen Symposium on Marine Environmental Sciences

2027 Xiamen Symposium on Marine Environmental Sciences

January 12-15, 2027

Energetic wind-generated near-inertial waves observed in a cyclonic eddy
ID:1038 Poster Presentation

2027-01-15 16:45 (China Standard Time)

Session:Session 3 - Tropical Cyclone-Ocean Interactions: From Weather to Climate Scales

Abstract
The propagation of wind-generated near-inertial waves (NIWs) is well-documented in anticyclonic eddies (ACEs), but remains rarely reported in cyclonic eddies (CEs). Here, subsurface mooring observations in the northwestern Pacific captured two distinct NIW packets (WP1 and WP2) generated by Typhoon Sanvu within a CE. In the typhoon’s wake, WP1 was confined to the upper 80 m, with little energy penetrating deeper despite strong wind forcing. A linear internal wave model and ray-tracing experiments suggest that the shallow mixed layer and the repelling effect of the CE favor lateral propagation of near-inertial energy rather than downward penetration. About two weeks later, WP2 emerged at 450–900 m depth with a velocity amplitude of 0.3 m/s and persisted for nearly one month. Wind work and WKB-scaled near-inertial kinetic energy indicate that WP2 was decoupled from local surface energy and unrelated to WP1. Spectral and modal analyses show that WP2 had the characteristics of low-mode and long-range-propagating NIWs. Ray-tracing and dynamical analyses suggest a plausible remote-source interpretation for WP2, in which it may have originated from a remote cyclonic region 250–350 km away and reached the mooring along a pathway modulated by mesoscale eddies. However, because the present analysis does not resolve the wave packet’s horizontal extent, spatial inhomogeneity of NIW energy may also affect the mooring observations and thus the interpretation of the decay of WP1, the later arrival of WP2, and the apparent lack of downward-moving energy between them. These results highlight the complexity of NIW propagation in eddy-rich environments.
 
Speaker
Zifei Chen Institute of Oceanology, Chinese Academy of Sciences

Author
Zifei Chen 中国科学院海洋研究所

    Important Dates

    • Jan 30

      2026

      Session / Event proposals open

    • Mar 31

      2026

      Session / Event proposals close
      (Extended to April 7)

    • Apr 30

      2026

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    • Apr 30

      2026

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    • Jun 30

      2026

      Abstract submissions close
      (Extended to July 21)

    • Aug 31

      2026

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    • Sep 15

      2026

      Scientific program released

    • Oct 15

      2026

      Early bird registration closes

    • Jan 12–15

      2027

      XMAS 2027