Subinertial Variations in the Soya Warm Current Revealed by HF Ocean Radars, Coastal Tide Gauges, and Bottom-Mounted ADCP

Subinertial variations in the Soya Warm Current (SWC) are investigated using data obtained by high frequency (HF) ocean radars, coastal tide gauges, and a bottom-mounted acoustic Doppler current profiler (ADCP). The SWC exhibited subinertial variations with a period of 5-20 days. The surface transport by the SWC was significantly correlated with the sea level difference between the Sea of Japan and Sea of Okhotsk for both the seasonal and subinertial variations, indicating that the SWC is driven by the sea level difference between the two seas. The subinertial variations in the SWC were significantly correlated with the meridional wind stress component over the region. Sea level difference through the strait caused by wind-generated coastally trapped waves along the east coast of Sakhalin and west coast of Hokkaido are considered to be a possible mechanism causing the subinertial variations in the SWC.