Variability of eddy kinetic energy in the Sea of Japan from satellite altimetry data

Abstract

The variability of the geostrophic eddy kinetic energy (EKE) in the Sea of Japan derived from weekly altimetric sea level anomalies spanning from 1992 through 2009 is studied. Nonorthogonal modes of variability are revealed accounting for more than 60% of the total variance. They capture the seasonal variation of the mesoscale energetics in the entire Sea of Japan with the EKE growing in the warm season up to the maximum in October through November and diminishing in the cold season down to the minimum in March through April. In the northern Sea of Japan (northward of the Subarctic Front), where the mean EKE is several times less than in the southern sea, areas of considerable variability are detected. Quasi-biennial EKE oscillations are revealed but not the trends covering the whole record.