Journal of Tropical Oceanography ›› 2023, Vol. 42 ›› Issue (4): 25-35.doi: 10.11978/2022157CSTR: 32234.14.2022157

• Marine Hydrology • Previous Articles     Next Articles

Observation characteristics of coastal waves in Sanya and their responses to typhoon processes

LI Junmin1,2,3(), LI Bo1,3, CHEN Wuyang1, LIU Junliang1,3()   

  1. 1. State Key Laboratory of Tropical Oceanography, Key Laboratory of Science and Technology on Operational Oceanography, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Guangzhou 510301, China
    2. Sanya Institute of Ocean Eco-Environmental Engineering, Sanya 572000, China
    3. Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou 511458, China
  • Received:2022-07-13 Revised:2022-08-31 Online:2023-07-10 Published:2022-09-01
  • Supported by:
    Hainan Provincial Natural Science Foundation of China(422MS160); Science and Technology Planning Project of Guangdong Province of China(2021B1212050023); National Natural Science Foundation of China(42130404); Key Research Program of Frontier Sciences, Chinese Academy of Sciences(QYZDJ-SSW-DQC034)

Abstract:

Long-term monitoring site was deployed in the southern Sanya Bay of the South China Sea, and continuous wave observations covering four seasons were carried out in April ~ October 2020 and December 2021 ~ February 2022. Based on the observational data, the basic statistical features of the wave in the sea area and their response characteristics to typhoon processes are systematically analyzed. The results show that the waves at the site are affected by local factors, such as wind field, bottom topography, shoreline, and current dynamics, thus showing characteristics of nearshore waves. Due to the weakening effect of shallow water topography and the control of shoreline boundary, the waves maintain long-term shoreward (i.e., northward) propagation with relatively small wave heights and periods, in which the significant wave heights and mean periods are less than 1 m and 4 s, respectively, for most of the time. Due to the influence of dynamic factors such as tidal current and sea-land breeze, the wave heights show a strong diurnal variation, and both wave heights and steepness increase (decrease) significantly when the flow direction is opposite to (the same with) the wave direction; driven by the strong wind speed in the same direction, the wave height and steepness also increased significantly. Waves respond significantly to the typhoon process, and the wave height increases significantly under the synergy of current. When the typhoon process is close to the site, the wave energy extends to both low and high frequencies, with the direction distribution changing significantly. If the path is far from the site, the wave energy mainly propagates to the site by the swell, and the energy distribution expands to low frequency while the direction distribution remains unchanged.

Key words: waves, tidal current, typhoon, in-situ observation