SEA LEVEL INTRA-ANNUAL VARIABILITY IN THE COASTAL NORTHWESTERN PART OF THE SEA OF JAPAN

Trusenkova O.O., Lobanov V.B., Primachev E.V.

Sea level variability was analyzed using tide gauge data for 2010–2015 from three Russian hydrometeorological stations located along the open coastline in the Primorye (Liman) Current zone, in the northwestern part of the Sea of Japan. Based on wavelet transform, non-stationary sea level oscillations on the 120–130 and 70–80 days timescales were detected for the first time in the northwestern part of the Sea of Japan. Quasi-biennial, annual, semiannual, tidal diurnal and semi-diurnal, and inertial sea level oscillations found in earlier studies were also registered. The intensity of dynamic processes was estimated from the wavelet spectral power averaged in the 8–40 days range corresponding to lifetimes of mesoscale/submesoscale eddies in the Primorye Current zone. The variability timescales of this intensity were found to match that of the sea level (more precisely, the timescales of 70 days and longer). This implies that the 120–130 and 70–80 days sea level variability can be related to dynamic processes. At the three coastal stations, more than 200 km distant from each other, this kind of variability was in phase before mid 2014 and then diverged.

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