本文对1998年南海季风实验中定点观测的声学多普勒流速剖面仪（Acoustic Doppler Current Profiler，ADCP ）海流数据进行频谱分析，结果表明南海北部地区内波之间的非线性作用的强弱影响着该海域的内波谱特征。在季节性温跃层（水深22m和58 m）中，由于存在着强的非线性作用，内波带的谱斜率趋于σ–1和σ–2之间，而且较高能量的潮谐波频率的峰值随着频率呈现少见的σ–3递减。在季节性温跃层（水深130m）以下，内波非线性相互作用较弱，观测的内波带谱特征与标准Garrett-Munk内波谱相似，均显示了σ–2的谱斜率。

The authors analyze the internal wave spectra of the ADCP（Acoustic Doppler Current Profiler） data from the South China Sea Monsoon EXperiment (SCSMEX) in 1998. The results suggest that the level of nonlinear interactions amongst internal waves affects the characteristics of internal wave spectra in the north South China Sea. In the seasonal thermocline (depths of 22 m and 58 m), the falloff rate of the spectra with frequency σ trends to fall between σ–1 and σ–2 for internal-wave band due to strong nonlinear interactions; furthermore, tidal harmonic frequency peaks with high energy show an amplitude decrease of σ–3 with frequency. Below the seasonal thermocline (depth 130 m), the nonlinear interactions are weakened with increasing depth so that the internal wave spectrum is similar to canonical Garrett-Munk spectrum, both showing a falloff rate of σ–2.