Studying wave-current interaction by HF radar

Improved understanding of the wave-current interaction can lead to better descriptions of ocean wave or wind and more precise designs of ocean engineering. High-frequency (HF) radar, as an important ocean remote sensing tool, can measure large-area currents and wave parameters simultaneously. Here, the first-order spectrum power (FSP) of HF radar is used to study the wave-current interaction. The frequency shift of the first-order spectrum is combined with its power to indicate the relationship between current and wave. The effects of current on the Bragg wave in different sea areas are presented by analyzing the FSP change with current vector (FSP-current distribution). The FSP-current distribution in deep water is very similar to the theoretical distribution of two-dimensional wave-current; while, the wave-current interaction over a relatively shallow shelf is stronger and more complicated. Experimental results illustrate the potential of HF radar in studying the wave-current interaction and show that the wave-current interactions in deep water mainly belong the two-dimensional oblique model (refraction case).