The large-scale circulation of the Pacific Ocean consists of two great anticyclonic gyres that contract poleward at increasing depth, two high-latitude cyclonic gyres that extend equatorward and westward below 500 m and wrap halfway around the cyclonic gyres, two westward flows along 10° - 15° north and south that are found from the surface to abyssal depths, an eastward flow that takes place north of the equator at the surface and at about 500 m, but lies along the equator at all other depths.
This pattern is symmetrical about the equator except for the northward flow across the equator in the west and the southward flow in the east.
As no water denser than about 26.8 in 
0 is formed in the North Pacific, the waters of the North Pacific below about 1000 m are dominated by the inflow from the South Pacific. Salinity and oxygen in the deeper water are higher in the South Pacific and the nutrients are lower. These characteristics extend along recognized paths as they move northward and circulate within the North Pacific.
Return flow is seen across the equator in the east. Part of it turns westward and then southward with the southward limb of the extended cyclonic gyre, and part passes westward and around the anticyclonic gyre and then southward with the cyclonic flow, and along the eastern boundary and through the Drake Passage.
To Abstract List
To Pacific Workshop
To WOCE Home Page