For 10 points, name this portion of Earth's hydrosphere that contains most of the world's saltwater.
An intrinsic oscillation governing this region is incorporated into Welander's model, which divides the surface of this region and its interior into two different sections. A simpler so-called "box model" for this region is Stommel's model, which treats this region as two separate parts of equally well-mixed fluid. In a 1947 paper, transport in this region was modeled with an equation in which the transport is proportional to a stress vector divided by the Rossby Parameter; that equation, the Sverdrup Relation, expresses how wind-forcing drives transport in this region. (*) Anti-cyclones cause this region to exhibit an upwelling behavior known as Ekman pumping. This region of the Earth undergoes periodic meridional overturning, and changes in temperature and salinity drive thermohaline circulation currents in it. For 10 points, name this portion of Earth's hydrosphere that contains most of the world's saltwater.
An intrinsic oscillation governing this region is incorporated into Welander's model, which divides the surface of this region and its interior into two different sections.
Earth's Oceans [prompt on water or seas or hydrosphere]