78 |
\subsubsection{Boundary conditions} |
\subsubsection{Boundary conditions} |
79 |
|
|
80 |
The upper and lower boundary conditions are : |
The upper and lower boundary conditions are : |
81 |
\begin{eqnarray*} |
\begin{eqnarray} |
82 |
\mbox{at the top:}\;\;p=0 &&\text{, }\omega =\frac{Dp}{Dt}=0 \\ |
\mbox{at the top:}\;\;p=0 &&\text{, }\omega =\frac{Dp}{Dt}=0 \\ |
83 |
\mbox{at the surface:}\;\;p=p_{s} &&\text{, }\phi =\phi _{topo}=g~Z_{topo} |
\mbox{at the surface:}\;\;p=p_{s} &&\text{, }\phi =\phi _{topo}=g~Z_{topo} |
84 |
\label{eq:boundary-condition-atmosphere} |
\label{eq:boundary-condition-atmosphere} |
85 |
\end{eqnarray*} |
\end{eqnarray} |
86 |
In $p$-coordinates, the upper boundary acts like a solid boundary ($\omega |
In $p$-coordinates, the upper boundary acts like a solid boundary ($\omega |
87 |
=0 $); in $z$-coordinates and the lower boundary is analogous to a free |
=0 $); in $z$-coordinates and the lower boundary is analogous to a free |
88 |
surface ($\phi $ is imposed and $\omega \neq 0$). |
surface ($\phi $ is imposed and $\omega \neq 0$). |
95 |
is not dynamically relevant and can therefore be subtracted from the |
is not dynamically relevant and can therefore be subtracted from the |
96 |
equations. The equations written in terms of perturbations are obtained by |
equations. The equations written in terms of perturbations are obtained by |
97 |
substituting the following definitions into the previous model equations: |
substituting the following definitions into the previous model equations: |
98 |
\begin{eqnarray*} |
\begin{eqnarray} |
99 |
\theta &=&\theta _{o}+\theta ^{\prime } \label{eq:atmos-ref-prof-theta} \\ |
\theta &=&\theta _{o}+\theta ^{\prime } \label{eq:atmos-ref-prof-theta} \\ |
100 |
\alpha &=&\alpha _{o}+\alpha ^{\prime } \label{eq:atmos-ref-prof-alpha}\\ |
\alpha &=&\alpha _{o}+\alpha ^{\prime } \label{eq:atmos-ref-prof-alpha}\\ |
101 |
\phi &=&\phi _{o}+\phi ^{\prime } \label{eq:atmos-ref-prof-phi} |
\phi &=&\phi _{o}+\phi ^{\prime } \label{eq:atmos-ref-prof-phi} |
102 |
\end{eqnarray*} |
\end{eqnarray} |
103 |
The reference state (indicated by subscript ``0'') corresponds to |
The reference state (indicated by subscript ``0'') corresponds to |
104 |
horizontally homogeneous atmosphere at rest ($\theta _{o},\alpha _{o},\phi |
horizontally homogeneous atmosphere at rest ($\theta _{o},\alpha _{o},\phi |
105 |
_{o}$) with surface pressure $p_{o}(x,y)$ that satisfies $\phi |
_{o}$) with surface pressure $p_{o}(x,y)$ that satisfies $\phi |