基于中法海洋卫星波谱仪观测的一维海浪谱模型对比

Comparisons on One-dimensional Ocean Wave Spectrum Models Based on SWIM/CFOSAT Observations

海浪谱模型不仅能表征粗糙海表面,还能揭示海浪能量随波数和方向的分布,为海洋探测等研究和应用提供必要信息。中法海洋卫星搭载的波谱仪可实现全球海浪方向谱的空间观测。根据现有海浪谱模型和海浪谱观测的发展现状,对波谱仪观测的海浪参数进行统计特征分析,在波谱仪观测的波数范围内(0.01~0.25rad·m^(–1)),进行不同海态下实测海浪谱与以Apel谱、Elfouhaily谱和Goda谱为代表的波高谱和曲率谱模型的比较,得到现有海浪谱观测与上述三种谱模型的差异,并结合海浪参数统计特征,对产生差异的原因进行讨论分析。结果表明,现有谱与波谱仪观测的差异来自于其对海态的不完全表达,且所表示的海态在自然状态中仅占有限比例。研究结论可以为海浪谱模型和观测的后续研究提供支持。

The ocean wave spectrum models not only characterize the rough sea surface but also reveal the internal energy distribution of waves with wave numbers and directions,providing information for air-sea interaction research and ocean exploration applications.The Surface Waves Investigation and Monitoring instrument(SWIM)onboard the China France Oceanography Satellite(CFOSAT)can ob-tain spatial observations of global ocean wave directional spectra.In this research,the status of existing wave spectrum models and observations were summarized,then the statistical characteristics of wave pa-rameters observed by SWIM are analyzed.To investigate the specific performance of the Apel spectrum,Elfouhaily spectrum,and Goda spectrum model in different sea states,the sea states are labelled in dif-ferent categories according to the well-applied wave field characterization features.Then the measured ocean wave spectra within the range of wave numbers(0.01~0.25 rad·m–1)under different sea states were compared with the height and curvature spectra in the spectrum models under different sea states.The differences between the existing wave observations and the above three spectra are quantified and combined in their statistical characteristics in terms of the ocean wave parameters.The results indicate that when the inverse wave age is less than 0.8,the Goda wave height spectrum and Elfouhaily curva-ture spectrum are the closest in terms of the wave height spectrum and curvature spectrum to SWIM observations respectively.When the inverse wave age is between 0.8 and 0.9,the Apel wave height spec-trum and curvature spectrum are most closely aligned with the measured data from SWIM.When the inverse wave age is between 0.9 and 1.0,the Goda wave height spectrum and Apel curvature spectrum are most closely matched with the wave height spectrum and curvature spectrum from the SWIM prod-uct respectively.Conclusions are drawn that the reasons for the differences between SWIM observations and existing models mentioned above are due to their conditional assumptions and incomplete expres-sion of the sea states,while in the natural sea environment,these assumptions hold but for quite a limit-ed fraction.The result supports the follow-up research of wave spectrum model and observation applica-tions.