Bottom Water Dissolved Oxygen

Bottom Water Salinity

Summertime salinity values generally range between 0.8 to $\approx$ 18 practical salinity units (psu) and the estuary is less saline in the spring and becomes more saline as the summer progresses  (Borsuk et al. 2001b; Luettich Jr. et al. 1999). Bottom salinity, $S_{\text{bot}}$ (psu), depends on depth, average temperature and the distance toward the eastern-most boundary of the estuary. Let $\zeta = \sin\left(\frac{2\pi}{365*24}(t - 3020)\right)$ (from Eqn A.4) and let $X$ denote the Gaussian random field (Appendix A.3.1) generated with $\sigma_{x,S}$, $\sigma_{y,S}$, and $\sigma_{t,S}$ set to 1000 (m), 800 (m) and 48 (hrs). The maximum salinity in the deepest parts of the estuary is given by:

$$= \begin{cases}& 8\sqrt{d_s} + 2\sqrt{d_s}(\sin(X) + 1) + 5(1+\sq... ...0 \\ & 8\sqrt{d_s} + 2\sqrt{d_s}(\sin(X) + 1) \quad : \zeta \leq 0. \end{cases}$$ (A.6)

The first two terms term causes salinity to increase toward the mouth of the estuary, while if $\zeta>0$ (which occurs between May 6 to Nov 4) a seasonal component is also added. Depth is accounted for by scaling $S(t)_$deep:

$$= S(t)_ \left(1 - \frac{\exp{\left(-D^2/2.25\right)}}{2}\right).$$ (A.7)

Thus, shallower parts of the estuary are always less saline than deeper parts.