Evaporation and ice formation cause salinity levels to increase. The thermohaline circulation has numerous effects on a coupled ocean and atmosphere. Since warm waters are driven northward, this contributes to the unusually mild European winters. In addition, the shifts in temperature and salinity affect marine ecology in the North Atlantic. Colder waters are nutrient-rich and contain a great deal of dissolved carbon dioxide, whereas warmer waters are oxygenated and stripped of nutrients.
Hurricanes are comparable to heat engines, feeding off of warm SSTs.
The stronger the thermohaline circulation, the more favorable tropical cyclone activity becomes, since a larger area has warm SSTs. The thermohaline circulation has been modeled to gain further insight into its impacts. Also, there is speculation that the thermohaline circulation may cease to exist if carbon dioxide levels continue to rise, causing extensive global warming. This would have a tremendous effect on global climate. Finally, significant research is being conducted to completely understand the link between the North Atlantic Oscillation and the Conveyor Belt.