Circulation in the ocean

At lower temperatures, reducing conditions are present (CH4 is stable) this is typical for the oceanic crust. Most of the hydrothermal water circulates in the oceanic crust at a temperature of around 420 K, and the reducing conditions present there are mainly controlled by the PPM mineral mixture (Alt et al., 1989). 

Sigman, D. M., Altabet, M. A., McCorkle, D. C., Francois, R., and Fischer, G. (2000). The delta N-15 of nitrate in the Southern Ocean Nitrogen cycling and circulation in the ocean interior. Journal of Geophysical Research Oceans 105(C8), 19599—19614. 

Relations between Wind Speed, Langmuir Circulation and Particle Circulation in the Ocean, Deep-Sea Res. (1971) 18, 639-643. 

LangsethM. G., Mottl M. J., Hobart M. A., and Fisher A. (1988) The distribution of geothermal and geochemical gradients near site 501/504 implications for hydrothermal circulation in the oceanic emst. Ocean Drill. Initial Rep. Ill, 23 —32. 

Schlieren production and motions. This is a fascinating phenomenon that can easily be observed during ice-cube melting in brines or sugar water solutions. Thin-layer schlieren of dense solution represent cold, dense boundary layers that are shed from ice cubes due to their sinking buoyancy. Such observations are small-scale counterparts of thermohaline circulation in the oceans and the fluid counterpart of subduction of the cold, dense boundary layer of the Earth (the lithosphere) into hot, less-dense mantle below. 

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