Gulf of Alaska
Winds and precipitation can both affect the Alaska Current. Winds are downwelling along the coastal area most of the year, which helps to keep the density contrast between central Gulf of Alaska water and fresher, lower density water on the shelf. The coastal current in the Gulf of Alaska is strongly baroclinic. Precipitation and coastal runoff reduce the water density on the shelf. Due to the baroclinic density field, the Alaska current is highly sheared vertically, and the cross-current density gradient is reflected by the offshore salinity gradient. The surface salinities are less than 30 PSU (Practical Salinity Unit) at the coastal areas, more than 31 PSU on the shelf, and more than 32.5 PSU in the central Gulf of Alaska. The mean transport of the baroclinic current near Kodiak Island in the western gulf of Alaska is approximately 10 Sv in the upper 1500 m.