利用多源遥感卫星数据研究南海内波的时空分布特征

利用1995～2005年300多幅ERS-1/2,Radarsat-1,ENVISAT、SPOT、Landsat、IRS和NOAA AVHRR图像统计了南海北部海洋内波的时间分布特征,并绘制了内波空间分布图,利用KdV方程和Levitus历史跃层资料反演了内波的振幅和波速等参数。研究结果表明,南海北部海洋内波出现的区域主要有3块:吕宋海峡,东沙岛和海南东北部。内波传播方向以西向为主。在吕宋海峡,相速度达3 m/s,内波振幅超过100 m。在东沙岛附近,相速度在1.5～2 m/s左右,振幅在20～80 m左右;东沙岛西面和北面,相速度在1～1.5 m/s左右,振幅在5～20 m左右。海南东北部,相速度在0.4～0.8 m/s左右,振幅在2～4 m左右。内波的时间分布特征为:内波以4～9月为高峰期,1～3月和11～12月为低峰期;在每个月里以16～19日为高峰期。

The Study of Spatial and Temporal Distribution Characteristics of Internal Waves in the South China Sea from Multi-satellite Data

More than 300 satellite images including SAR(ERS1/2,Radarsat and Envisat),SPOT,Landsat,IRS and NOAA AVHRR images from 1995 to 2005 were analyzed to obtain spatial and temporal distribution of internal waves in the South China Sea(SCS).The amplitude and speed are calculated based on the KdV equation and Levitus' historical mix-layer depth data.The statistical analysis showed that three areas including Luzon Strait,Dongsha Island and the Northeastern Hainan Island were found to have regular internal wave activity.Most of the internal waves travel westly.Near the Luzon Strait,the phase speed can reach 3 m/s,the amplitude can exceed 100 m;near the Dongsha Island,the phase speed is in 1.5~2 m/s around,the amplitude is in 20~80 m around;in the western and northern part of Dongsha Island,the phase speed is in 1~1.5 m/s around,the amplitude is in 5~20 m around;in the northeastern of Hainan,the phase speed is in 0.4~0.8 m/s around,the amplitude is in 2~4 m around.The temporal distribution characteristics of internal waves are: the internal waves occur mostly from Apr.to Sept.,little internal waves are observed from Jun.to Mar.and Nov.to Dec.;in every month the internal waves have highly activities from 16 to 19th day.