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Aleutian eddies are anticyclonic vortices on scale of 100–200 kilometers that transport the Alaskan Stream warm water originating in the Gulf of Alaska to the western Subarctic Pacific (WSP). We present an analysis of satellite, Argo floats and ship borne observations of Aleutian eddies, revealing the influence of the wind forcing on the eddy formation and shedding. We demonstrate that the eastern winds promote the Aleutian eddy formation south of Near Islands. Positive (cyclonic) wind stress curl in late fall- winter results in the SSH decrease and the mesoscale cyclones formation at the Aleutian eddy boundaries and thereby leads to the eddy shedding from the Alaskan Stream. An appearance of the Aleutian eddies in the central part of the WSP is accompanied by the deepening of the isopycnals and an increase of the temperature and dissolved oxygen (DO) concentration in 150–400 m layer. The eddies decrease the DO concentration on 26.7σθ and 26.8σθ surfaces in the upper intermediate layer but enrich the 27.0σθ surface by DO. The extent to which eddies modulate the temperature and DO concentration in the WSP is related to the SSH amplitude of eddies.

To study the water dynamics in the western Bering Sea, the time series of geostrophic velocities derived from satellite altimetry, Global total current (Copernicus Globcurrent) velocities, Argo buoys, and ship, borne data are analyzed. We demonstrate that the surface currents in the study area are characterized by a significant seasonal and interannual variability. In January, the southwestern currents are prevailing in the western Bering Sea, the geostrophic currents are connected to the continental slope, and mesoscale anticyclonic movement of waters is observed on the shelf. In July, the surface flow is oriented to the northeast along the continental slope, and cyclonic water movement prevails on the shelf. The formation of mesoscale anticyclones in late winter – early spring – is related to the supply of low-temperature and low-salinity Bering Sea shelf water. The temporal variability of the direction and current velocity in the western part of the Bering Sea during the summer period is associated with the wind and coastal upwelling. The presence of coastal upwelling and eddies should be considered as one of the factors leading to the high concentration of chlorophyll a on a shelf and continental slope in the summer.

Large canyons incise the shelf break of the eastern Bering Sea to be preferred sites of the cross-shelf exchange. The mesoscale eddy activity is particularly strong near the shelf-break canyons. To study the mesoscale dynamics in the Navarin Canyon area of the Bering Sea, the time series of velocities derived from AVISO satellite altimetry between 1993 and 2015, drifters, Argo buoys, and ship-borne data are analyzed. We demonstrate that the strength of anticyclonic eddies along the shelf edge in spring and summer is determined by the wind stress in March–April. The increased southward wind stress in the central Bering Sea forced a supply of low-temperature and low-salinity outer shelf water to the deep basin and formation of the anticyclonic mesoscale circulation seaward of the Navarin Canyon. Enhanced northwestward advection of the Bering Slope Current water leads to increase in an ice-free area in March and April and increased bottom-layer temperature at the outer shelf. The strong (weak) northwestward advection of the eastern Bering Sea waters, determined by eastern winds in spring, creates favorable (unfavorable) conditions for the pollock abundance in the western Navarin Canyon area in summer.

Year-to-year changes of the Alaskan Stream surface flow, forming the northern boundary of the western subarctic cyclonic gyre in the Pacific, impact the dynamics of water in the eastern Okhotsk Sea. It is shown by Lagrangian simulation of transport of the Alaskan Stream waters in 20 year-long AVISO velocity field and direct computation of the corresponding fluxes that an intensification/weakening of the Alaskan Stream current leads to increased/decreased northward fluxes in the areas of the Krusenstern and Fourth Kuril straits connected the Okhotsk Sea with the Pacific Ocean. Enhancement of the Alaskan Stream flux is accompanied by an increase in water temperature and decreasing ice area in the Okhotsk Sea in winter. The Alaskan Stream surface flux is shown to be negatively correlated with satellite-derived chlorophyll-a concentration in May from r = − 0.68 to − 0.73 in 1998–2013 and with winter–spring biomass of large-sized zooplankton with r = − 0.70 in 1995–2012. It is positively correlated with winter–spring biomass of small- and medium-sized zooplankton in the eastern Okhotsk Sea with r = 0.74 in 1995–2012.

The Alaskan Stream is the western boundary current in the subarctic North Pacific. The Alaskan Stream area is characterized by a significant temperature, salinity and density differences between the coastal and open-ocean waters and strong mesoscale dynamics. In this paper, we demonstrate the transport pathways of the Alaskan Stream Water in the eastern subarctic Pacific and its extension into the eastern Bering Sea from 1 October 1994 to 12 September 2016 with the help of altimetry-based Lagrangian maps. Mesoscale eddy activity along the boundary between the shelf and deep-basin in the Alaskan Stream region and the eastern Bering Sea is shown to be related to the wind stress curl in the northern North Pacific in winter. A significant correlation is found between the concentration of chlorophyll a in the Alaskan Stream area and eastern Bering Sea in August–September and the wind stress curl in the northern North Pacific in November–March. The mesoscale dynamics, forced by the wind stress curl in winter, may influence not only lower trophic-level organism biomass but also salmon abundance and catch in the study area.

The Lagrangian technique is applied to model the eddy dynamics and the flow across the Near Strait (NS) based on satellite derived SSH anomalies. Daily Lagrangian latitudinal maps, computed with the AVISO surface velocity field, and calculation of the flow across the strait, connecting the Pacific Ocean with the Bering Sea, show that the water flux is highly variable and controlled by mesoscale and submesoscale eddies. On the seasonal scale, the flux through the western part of the NR is negatively correlated with the flux through its eastern part ( r = - 0.93 ). On the interannual time scale, a significant positive correlation ( r = 0.72 ) is diagnosed between the NS flow and the wind stress in winter. Increased southward component of the wind stress decreases the northward water flow through the strait. Positive wind stress curl over the strait area in winter–spring generates a cyclonic circulation and thereby enhances the southward flow in the western part ( r = - 0.68 ) and northward flow in the eastern part ( r = 0.61 ). In fall, the water flow in different parts of the NS is determined by the strength of the anticyclonic mesoscale eddy located in the Alaskan Stream area.

The seasonal and interannual variability of mesoscale circulation along the eastern coast of the Sakhalin Island in the Okhotsk Sea is investigated using the AVISO velocity field and oceanographic data for the period from 1993 to 2016. It is found that mesoscale cyclones with the horizontal dimension of about 100 km occur there predominantly during summer, whereas anticyclones occur predominantly during fall and winter. The cyclones are generated due to a coastal upwelling forced by northward winds and the positive wind stress curl along the Sakhalin coast. The anticyclones are formed due to an inflow of low-salinity Amur River waters from the Sakhalin Gulf intensified by southward winds and the negative wind stress curl in the cold season. The mesoscale cyclones support the high biological productivity at the eastern Sakhalin shelf in July– August.

Using Lagrangian methods we analyze a 20-year-long estimate of water flux through the Kamchatka Strait in the northern North Pacific based on AVISO velocity field. It sheds new light on the flux pattern and its variability on annual and monthly time scales. Strong seasonality in surface outflow through the strait could be explained by temporal changes in the wind stress over the northern and western Bering Sea slopes. Interannual changes in a surface outflow through the Kamchatka Strait correlate significantly with the Near Strait inflow and Bering Strait outflow. Enhanced westward surface flow of the Alaskan Stream across the $174^\circ$ E section in the northern North Pacific is accompanied by an increased inflow into the Bering Sea through the Near Strait. In summer, the surface flow pattern in the Kamchatka Strait is determined by passage of anticyclonic and cyclonic mesoscale eddies. The wind stress over the Bering basin in winter - spring is responsible for eddy generation in the region.