NewTest

\begin{equation}\tag{176} k_b = 0.062 \left[ 1-0.9 \tanh \left( 0.25\frac{u_{*w}}{W_s} \right) \right] \end{equation}

\begin{equation} {{\sigma }_{E}}=\left\{ \begin{align}

 & 0.7+3.6{{\sin }^{2}}\left( \frac{\pi }{2}\frac{{{W}_{s}}}{{{u}_{*c}}} \right)
   \text{if}\frac{{{W}_{s}}}{{{u}_{*c}}}\le 1 \tag(136) \\
 & 1.0+3.3{{\sin }^{2}}\left( \frac{\pi }{2}\frac{{{u}_{*c}}}{{{W}_{s}}} \right)
   \text{if}\frac{{{W}_{s}}}{{{u}_{*c}}}>1 \\

\end{align} \right. \end{equation}