2019 Volume 28 Issue 2 Pages 19-40
The general circulation of the ocean has been classified into two types of circulation: winddriven circulation, represented by gyres, and thermohaline circulation, driven by surface buoyancy flux. The latter circulation type is the deep ocean circulation characterized by local deepwater formation at high latitudes and deep-water upwelling over other vast areas. This deep circulation is considered to play an important role in the climate because it involves large transport of heat and materials such as nutrients and carbon compounds. The author investigated its driving mechanisms from the viewpoint of energetics through energy budget analysis of numerical models. The study extends the analysis to enhancement of the thermohaline circulation due to winds over the Southern Ocean and to geothermal heating, quantification of potential energy sinks and the role of the nonlinearity of the equation of state (EoS), water mass transformation and the enhancement of the thermohaline circulation due to the nonlinear effects of EoS, and importance of the nonlinearity of EoS in the available potential energy budget.
