Spatial Patterns of the Primorye Current in the Northwestern East/Japan Sea on Satellite Images and Standard Sections.

Spatial patterns of the Primorye Current, as a band of cold water along the coast of Primorye (northwestern East/Japan Sea), are considered on the data of satellite images and standard sections obtained in 2000–2020. The data of AVHRR and MODIS scanners mounted on the satellites NOAA, Terra and Aqua are used with spatial resolution of 1.0–1.1 km. Temperature and salinity profiles in the upper 500 m layer were measured at the standard sections directed southward and east-southeastward from Vladivostok. The new data contradict a false supposition about the current origin from the Okhotsk Sea that is preserved in the name of “Liman Current”, still used sometimes. The cold-water area prolongs from the southern Tatar Strait to Peter the Great Bay but is definitely separated from the Amur Liman. Its core with the lowest SST is usually located on the external shelf of Primorye, outside of the Tatar Strait. Shape of the cold-water area is complicated and highly variable; it looks seldom as an alongshore flow, but more frequently as chains of eddies or filaments. In winter, the Primorye Current is presented usually as a wide uninterrupted alongshore belt with many intrusions to the warmer waters. This belt is distorted in spring by mesoscale eddies. In summer, the cold-water zone is narrowed and sometimes interrupted between 43 and 45°N; the cold waters interact with large anticyclonic eddies which transport the warm subtropic water close to the shore. The cold-water zone begins to extend again in fall season: large eddies and cold intrusions spread offshore, and upwellings appear at the coast. In November–December, summer stratification is destroyed and the warm water advection is weakened, so the solid band of cold water mixed by convection occupies a vast area of the northwestern East/Japan Sea off the coast of Primorye. Observed structural patterns show that the cold water at the sea surface along the coast of Primorye is produced on the shelf by upwellings or tidal mixing. Possible mechanisms of the cold spot inducing are discussed. [ABSTRACT FROM AUTHOR]