where K* = 10-4 m2/s is the maximum diapycnal diffusivity for salt Angering; Kis the constant diapycnal diffusivity due to other mixing processes unrelated to double diffusion.

= 0.3 x 10-4 m2/s was used in many studies (e.g., Zhang et al, 1998). Rc = 1.6 is the critical density ratio above which the diapycnal mixing due to salt fingering drops dramatically, due to the absence of staircases; n = 6 is an index to control the decay of Kq, Ks with increasing Rp.

For the case of diffusive layering, the eddy diffusivities can be parameterized as

where C = 0.0032exp {4.8Rp-72},RF = 1 ^J/V ,Ra = 0.25 x 109R-1.1.

Accordingly, the dependence of eddy diffusivity of heat and salt is shown in Figure 5.115.

During salt fingering, density flux induced by vertical mixing is downward, i.e., the center of mass for a water column moves downward in the gravity field. As a result, the total amount of gravitational potential energy of the water column is reduced. The release

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