Thermohaline circulation

Common card · No. 219505

Thermohaline circulation (THC) is a part of the large-scale ocean circulation driven by global density gradients formed by surface heat and freshwater fluxes. The name thermohaline is derived from thermo-, referring to temperature, and haline, referring to salt content—factors which together determine the density of sea water. Wind-driven surface currents (such as the Gulf Stream) travel polewards from the equatorial Atlantic Ocean, cooling and sinking en-route to higher latitudes – eventually becoming part of the North Atlantic Deep Water – before flowing into the ocean basins. While the bulk of thermohaline water upwells in the Southern Ocean, the oldest waters (with a transit time of approximately 1000 years) upwell in the North Pacific; extensive mixing takes place between the ocean basins, reducing the difference in their densities, forming the Earth's oceans a global system. The water in these circuits transport energy (as heat) and mass (as dissolved solids and gases) around the...

Read on Wikipedia · Image Robert Simmon, NASA. Minor modifications by Robert A. Rohde also released to the public domain, Public domain