The fundamental characteristics of current in the Bering Strait and the Chukchi Sea from July to September 2003

The characteristics of current in the Bering Strait and the Chukchi Sea are analyzed based on the two current data on the mooring stations during the Second National Arctic Research Expedition of China in 2003.The tidal currents of the principal diurnal and semidiurnal ellipses rotate clockwise in the upper layer,except for N₂,S₂,and Q₁ at Sta.ST.In the Bering Strait(Sta.ST),the major semiaxis of tidal current constituent M₂ is 2.9 cm/s in the upper layer,which is much smaller than that of semi-monthly oscillation(11.8 cm/s); and the mean current flows northwestward at the amplitude of about 20 cm/s and varies a little with depth.During the cruise,the current has significant semi-monthly oscillation at the two mooring stations.The spectra analyses of the air pressure gradient and the wind stress show that there are the semi-monthly oscillations in these two data series.The near-inertial current,approximately 4 cm/s,presents almost the same magnitude of the principal tidal currents in the Bering Strait.