Thermohaline Ocean Circulation

The thermohaline circulation is that part of the ocean circulation which is driven by fluxes of heat and freshwater across the sea surface and subsequent interior mixing of heat and salt. The term thus refers to a driving mechanism. Important features of the thermohaline circulation are deep water formation, spreading of deep waters partly through deep boundary currents, upwelling and near-surface currents, together leading to a large-scale deep overturning motion of the oceans. The large heat transport of the thermohaline circulation makes it important for climate, and its non-linear and potentially abrupt response to forcing have been invoked to explain abrupt glacial climate changes. Anthropogenic climate change is likely to weaken the thermohaline circulation in future, with some risk of triggering abrupt and/or irreversible changes.