CMS-Flow:Boundary Conditions

Tidal Constituent

The water level predictions are based on a harmonic equation with several arguments

$\eta (t)=\sum _{i=1}^{N}f_{i}A_{i}\cos(\omega _{i}t+V_{i}^{0}+u_{i}-\kappa _{i})$

(1)

where $A$ is the constituent mean amplitude, $f$ is a factor that reduces the mean amplitude and varies in time, $V_{0}+u$ are the constituents equilibrium phase and $\kappa$ is the constituent phase lag or epoch. Table 1 shows a list of the currently supported tidal constituents in CMS.

Constituent	Speed
M2	28.984104
S2	30.000001
N2	28.439730
K2	28.984104
M4	30.000001
O1	28.439730
M6	28.984104
MK3	30.000001
S4	28.439730
MN4	28.984104
NU2	30.000001
S6	28.439730

Flux

The water flux is specified as m^3/sec per cell along the cell string. This value is multiplied by the number of cells in the cell string to obtain the total flux. The total flux is then redistributed along the boundary according to

$q_{i}={\frac {Q_{b}}{\sum \Delta s_{i}h_{i}^{1+r}/n_{i}}}{\frac {h_{i}^{1+r}}{n_{i}}}$

(2)

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Symbol	Description
$t$	Time
$A$	Constituent mean amplitude
$f$	Constituent nodal factor
$V^{0}$	Constituent equilibrium argument
$u$	Constituent equilibrium argument
$\kappa$	Constituent phase or epoch

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