Pacific decadal oscillation and sea level in the Japan/East sea

Satellite altimetric data from September 1992 to January 2002 and hydrographic data from 1927 to 1999 reveal the presence of low-frequency variability of sea surface height (SSH) within the Japan/East Sea (JES). SSH interannual variability amounting to approximately 15 cm is in phase with the Pacific Decadal Oscillation (PDO), with higher SSH, warmer, fresher surface (upper 200 dbar) layer during negative phases of the PDO; and lower SSH, cooler, saltier surface layer during a positive PDO. The JES SSH correlation with PDO appears to be related to changes in the geostrophic transport of the Kuroshio, which is weaker during a negative PDO (stronger during positive PDO). The transport of the Tsushima Current, which feeds the JES, is reported to be out of phase with the Kuroshio transport, thus delivering more buoyant subtropical water to the JES when the Kuroshio is weak. Part of the JES baroclinic PDO-related variability may also be due to changes in the freshwater inflow from the East China Sea, which is closely associated with the discharge of the Yangtze River.