Long-term observation of the soya warm current combining hf ocean radars with coastal tide gauges and satellite altimetry

Three High Frequency (HF) ocean radars were installed at the Soya Strait in the Sea of Okhotsk to monitor the Soya Warm Current (SWC), which flow through the Soya/La Perouse Strait. The frequency of the HF radar is 13.9 MHz, and the range and azimuth resolutions are 3 km and 5 deg., respectively. The radar covers a range of approximately 70 km from the coast. These stations had been operated for 19 years since August 2003. In this paper, interannual variations in the SWC are investigated by using the surface current fields obtained by the HF ocean radars combined with coastal tide gauge records and sea level anomaly from satellite altimetry.