Seasonal Variations of Oceanic Conditions near the Southeastern Coast of Sakhalin Island
G. V. Shevchenko and V. N. Chastikov
Seasonal variations of hydrological conditions in the area adjoining the southeastern coast of Sakhalin Island are described based on the analysis of monthly mean temperature and salinity obtained over standard oceanic sections Makarov–Cape Georgii and Cape Svobodny–the sea and from nine oceanic surveys. The Poronai River runoff that promotes the formation of a warm surface layer with low salinity largely influences the water area of Terpeniya Bay in the northern part of the area studied. In spring, these waters primarily spread southward along the coast; in summer, they flow southeastward, forming a weak vortex structure at 144E. In the fall, major changes occur below 20 m, where waters of the cold intermediate layer are replaced by warmer waters (4–6C) of low salinity connected with the Amur River runoff. The destruction of the CIL core near the shelf edge at depths of about 100 m resulting from the fall intensification of the East Sakhalin Current is pronounced in the southern, abyssal part of the region. The coastal area is covered by waters with salinity below 32‰ connected with the Amur River runoff. The volume of low-salinity waters coming through the Cape Svobodny–the sea section into the southern part of the Sea of Okhotsk is estimated at 3000 km3 taking into account instrumental measurements of flow rates.