35.2.1 hl_diffusivity

Held and Larichev (1996) specified a time and length scale given by

 

$$\frac{f^{2}}{D} \int^{-D_{t}}_{-D_{b}} \, Ri^{-1} \, dz$$ T^-2 = (35.84)

$$\beta_{eff} \, T,$$ L^-1_hl = (35.85)

where D = D_b - D_t. The resulting diffusivity is given by

$$\kappa L^{2}_{hl} \, T^{-1}$$ =

$$(\beta_{eff}^{2} \, T^{3})^{-1}.$$ = (35.86)

The time scale is related to the growth rate of a baroclinic wave (an Eady growth rate; on the order of days), and the length scale is related to the Rhines' scale.