Editing Pacific Ocean (section)

== Water circulation ==
Winds drive large systems of surface currents across the Pacific. Trade winds carry tropical surface water westward through the North Equatorial Current and South Equatorial Current. Part of this water returns eastward through the Equatorial Countercurrent. In the North Pacific, the [[Kuroshio Current]] carries warm tropical water northward past the Philippines and Japan. The North Pacific Current then moves water eastward across the ocean. Near North America, the [[California Current]] carries cool water south along the western coast.

The South Pacific circulation follows a comparable pattern. The East Australian Current transports warm water southward along Australia. On the opposite side of the basin, the [[Humboldt Current]] carries cold water northward along Chile and Peru. Winds push surface water away from the South American coast, allowing cold water containing dissolved nutrients to rise from greater depths.

Surface salinity is generally highest in the subtropical Pacific, where evaporation exceeds rainfall. Salinity is lower near the equator because of heavy precipitation. It also decreases at high latitudes where rainfall and melting ice add fresh water. Much of the Pacific's deep water originally forms in the Atlantic or near Antarctica before entering the basin through the Southern Ocean. Its slow movement makes deep Pacific water older and lower in dissolved oxygen than recently formed deep water elsewhere.