6.8 Snow-Ice Conversion

Snow to ice conversion occurs if the snow layer overlying the sea ice becomes thick enough to depress the snow-ice interface below freeboard (the ocean surface). This process is only accounted for when CAM 3.0 is coupled to a mixed layer ocean, otherwise the snow depth is merely capped at 0.5 m. The interface height is:

$$z_{int} = h - (\rho_s h_s + \rho_i h) / \rho_o.$$ (6.51)

If $z_{int} < 0$, then an amount of snow equal to $-z_{int} \rho_i / \rho_s$ is removed from the snow layer and added to the ice. It is assumed that ocean water floods the depressed snow, and then converts it into ice of thickness $-z_{int}$. The energy of melting of the newly formed ice is: $q_{flood} = q_s \rho_i / \rho_s$. Note that such conversion is assumed to occur with no heat or salt exchange with the ocean.