I.3 Exudation

The exudation rate of a phytoplankton group is a /day rate. It is computed within the WQ Module as per Equation (I.12).

\[\begin{equation} R_{exud\langle computed\rangle}^{phy} = R_{prod\langle computed\rangle}^{phy} \times f_{exud}^{phy} \tag{I.12} \end{equation}\]

\(R_{prod\langle computed\rangle}^{phy}\) is the previously computed phytoplankton primary production rate (Equations (I.2), and potentially (I.3) and (I.4)), and \(f_{exud}^{phy}\) is the user defined (or default) fraction of primary production lost to exudation. This exudation loss is a linear function.

If a group’s ambient phytoplankton concentration is less than the user defined (or default) minimum concentration \(\left[PHY\right]_{min}\), then the exudation rate is set to zero.