고주파 레이더 자료를 활용한 제주해협 표층 조류 추정 = An Evaluation of Surface Tidal Current Estimation Based on HF Radar Data

다국어 초록 (Multilingual Abstract)

This study conducted harmonic analysis of the surface current data observed in 2024 over the Jeju Strait using High-Frequency (HF) radar, and quantitatively classified the spatial propagation characteristics of tidal currents into standing and progressive waves. Tidal ellipses derived for each grid point-characterized by major and minor axis, phase, and amplitude-were used to reconstruct predicted currents. These were then compared with observed tidal elevations from the Korea Hydrographic and Oceanographic Agency (KHOA)’s tidal stations, and phase difference (Δϕ) was applied as the classification criterion. The classification criteria were defined as follows: progressive waves for Δϕ within 0° to ±22.5°, mixed wave zones for ±22.5° to ±45°, and standing waves for ±45° to ±90°. Spatial analysis showed that the central Jeju Strait and the southwestern waters near Chuja Island exhibited dominant progressive wave characteristics, whereas strong standing wave characteristics were found in the northeastern and southeastern coastal areas of Jeju and around smaller islands, where Δϕ exceeded ±45°. The mixed wave zone appeared along the northern and eastern coasts of Jeju Island and in the inner strait, showing complex propagation dynamics. To validate observational accuracy, HF radar data were compared with measurements from Trawl-Resistant Bottom Mount (TRBM) moored ADCPs. The results showed high agreement at shallower stations T1 to T3 (Fig. 1), but lower consistency at deeper locations T4 and T5 (Fig. 1), likely due to inherent ADCP beam geometry and differences in sampling depth. This research provides a quantitative assessment of tidal waveforms across the Jeju Strait using phase difference–based spatial classification. The results offer foundational insights for improving prediction accuracy in straits with mixed coastal and open-ocean characteristics. In particular, implementing region-specific models that distinguish between progressive and standing waves may significantly contribute to enhanced maritime safety, search and rescue operations, and marine energy applications.