How does thermohaline circulation connect the oceans?
Thermohaline circulation is ocean movement between surface and depth driven partly by density differences from temperature and salinity.
Formation process and geographic mechanism
At high latitudes cold salty water can become dense and sink, then move slowly through deep basins. Mixing and winds return water toward the surface elsewhere. This overturning transports heat, dissolved carbon, oxygen and nutrients. The conveyor-belt image is useful but oversimplifies many branches, eddies and changing speeds.
Spatial outcomes, measurement and management
Added freshwater can lower surface density and weaken some sinking regions, but the entire global system does not stop instantly. Changes can affect sea level, regional climate and ecosystems. Scientists combine temperature-salinity profiles, chemical tracers, current meters and satellites. Decades of records are needed to separate short variability from trends.