Energy characteristics of tidal and residual level variations in the Okhotsk Sea from satellite altimetry data

A unified satellite altimetry database, TOPEX/Poseidon (1993–2002) and Jason-1 (2002–2007) containing about 7,000 locations, was created for the Okhotsk Sea and adjacent areas. Amplitudes and phases of main tidal consituents were calculated for each location, and maps of tidal character and height were constructed. It is shown that diurnal waves dominate in the amphidromic areas of semidiurnal waves in Sakhalinsky Bay, near the Yamskie Islands, and the eastern Sakhalin coastline. Tidal energy increases along the axis southwest– northeast and reaches maximal values in Shelikhov Bay. Root mean square amplitudes of residual time series were taken to represent non-tidal sea level variations. Areas with the highest values were considered to be energetic ocean zones. They have been found near the southeastern Kamchatka coast and on the Pacific shelf side of Hokkaido where mesoscale eddies are often observed. To a lesser extent they relate to the whole KurilKamchatka deep trench (especially to its outside edge), as well as to the western Hokkaido shelf and northern Okhotsk Sea shelf where seasonal changes in currents are significant. A map showing the relative portion of tides and residual variations in total sea level energy has been constructed.