Role of surface winds in SAR signatures of oceanic internal waves in the northern South China Sea

摘要

It is well known that synthetic aperture radars (SARs) can image oceanic internal waves (OIWs). The signatures of OIWs on SAR images result from the modulation of wind-generated surface waves by the surface currents associated with the OIWs. The role of surface winds in SAR signatures of OIWs in the northern South China Sea is examined using SAR images and BlendQscat wind data. A radar imaging model for simulating SAR signatures of OIWs is also used to estimate the dependence of the radar signatures associated with OIWs on wind conditions. The results show that the signatures of OIWs on SAR images in the northern South China Sea are highly dependent on the wind speed. The temporal variations of the OIWs observed by SAR are closely related with the temporal variations of the wind speed in the study area.