12 |
\begin{eqnarray} |
\begin{eqnarray} |
13 |
\frac{D\vec{\mathbf{v}}_{h}}{Dt}+f\hat{\mathbf{k}}\times \vec{\mathbf{v}}% |
\frac{D\vec{\mathbf{v}}_{h}}{Dt}+f\hat{\mathbf{k}}\times \vec{\mathbf{v}}% |
14 |
_{h}+\mathbf{\nabla }_{p}\phi &=&\vec{\mathbf{\mathcal{F}}} |
_{h}+\mathbf{\nabla }_{p}\phi &=&\vec{\mathbf{\mathcal{F}}} |
15 |
\label{eq-p-hmom-start} \\ |
\label{eq:atmos-mom} \\ |
16 |
\frac{\partial \phi }{\partial p}+\alpha &=&0 \label{eq-p-hydro-start} \\ |
\frac{\partial \phi }{\partial p}+\alpha &=&0 \label{eq-p-hydro-start} \\ |
17 |
\mathbf{\nabla }_{p}\cdot \vec{\mathbf{v}}_{h}+\frac{\partial \omega }{% |
\mathbf{\nabla }_{p}\cdot \vec{\mathbf{v}}_{h}+\frac{\partial \omega }{% |
18 |
\partial p} &=&0 \label{eq-p-cont-start} \\ |
\partial p} &=&0 \label{eq:atmos-cont} \\ |
19 |
p\alpha &=&RT \label{eq-p-eos-start} \\ |
p\alpha &=&RT \label{eq:atmos-eos} \\ |
20 |
c_{v}\frac{DT}{Dt}+p\frac{D\alpha }{Dt} &=&\mathcal{Q} \label{eq-p-firstlaw} |
c_{v}\frac{DT}{Dt}+p\frac{D\alpha }{Dt} &=&\mathcal{Q} |
21 |
|
\label{eq:atmos-heat} |
22 |
\end{eqnarray} |
\end{eqnarray} |
23 |
where $\vec{\mathbf{v}}_{h}=(u,v,0)$ is the `horizontal' (on pressure |
where $\vec{\mathbf{v}}_{h}=(u,v,0)$ is the `horizontal' (on pressure |
24 |
surfaces) component of velocity,$\frac{D}{Dt}=\vec{\mathbf{v}}_{h}\cdot |
surfaces) component of velocity,$\frac{D}{Dt}=\vec{\mathbf{v}}_{h}\cdot |
44 |
\end{equation} |
\end{equation} |
45 |
Potential temperature is defined: |
Potential temperature is defined: |
46 |
\begin{equation} |
\begin{equation} |
47 |
\theta =T(\frac{p_{c}}{p})^{\kappa } \label{eq-potential-temp} |
\theta =T(\frac{p_{c}}{p})^{\kappa } \label{eq:potential-temp} |
48 |
\end{equation} |
\end{equation} |
49 |
where $p_{c}$ is a reference pressure and $\kappa =R/c_{p}$. For convenience |
where $p_{c}$ is a reference pressure and $\kappa =R/c_{p}$. For convenience |
50 |
we will make use of the Exner function $\Pi (p)$ which defined by: |
we will make use of the Exner function $\Pi (p)$ which defined by: |
68 |
\] |
\] |
69 |
and on substituting into (\ref{eq-p-heat-interim}) gives: |
and on substituting into (\ref{eq-p-heat-interim}) gives: |
70 |
\begin{equation} |
\begin{equation} |
71 |
\Pi \frac{D\theta }{Dt}=\mathcal{Q} \label{theta-equation} |
\Pi \frac{D\theta }{Dt}=\mathcal{Q} \label{eq:potential-temperature-equation} |
72 |
\end{equation} |
\end{equation} |
73 |
which is in conservative form. |
which is in conservative form. |
74 |
|
|
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} |
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 |
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 } \\ |
\theta &=&\theta _{o}+\theta ^{\prime } \label{eq:atmos-ref-prof-theta} \\ |
100 |
\alpha &=&\alpha _{o}+\alpha ^{\prime } \\ |
\alpha &=&\alpha _{o}+\alpha ^{\prime } \label{eq:atmos-ref-prof-alpha}\\ |
101 |
\phi &=&\phi _{o}+\phi ^{\prime } |
\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 |
118 |
\begin{eqnarray} |
\begin{eqnarray} |
119 |
\frac{D\vec{\mathbf{v}}_{h}}{Dt}+f\hat{\mathbf{k}}\times \vec{\mathbf{v}}% |
\frac{D\vec{\mathbf{v}}_{h}}{Dt}+f\hat{\mathbf{k}}\times \vec{\mathbf{v}}% |
120 |
_{h}+\mathbf{\nabla }_{p}\phi ^{\prime } &=&\vec{\mathbf{\mathcal{F}}} |
_{h}+\mathbf{\nabla }_{p}\phi ^{\prime } &=&\vec{\mathbf{\mathcal{F}}} |
121 |
\label{eq-p-hmom} \\ |
\\ |
122 |
\frac{\partial \phi ^{\prime }}{\partial p}+\alpha ^{\prime } &=&0 |
\frac{\partial \phi ^{\prime }}{\partial p}+\alpha ^{\prime } &=&0 |
123 |
\label{eq-p-hydro} \\ |
\\ |
124 |
\mathbf{\nabla }_{p}\cdot \vec{\mathbf{v}}_{h}+\frac{\partial \omega }{% |
\mathbf{\nabla }_{p}\cdot \vec{\mathbf{v}}_{h}+\frac{\partial \omega }{% |
125 |
\partial p} &=&0 \label{eq-p-cont} \\ |
\partial p} &=&0 \\ |
126 |
\frac{\partial \Pi }{\partial p}\theta ^{\prime } &=&\alpha ^{\prime } |
\frac{\partial \Pi }{\partial p}\theta ^{\prime } &=&\alpha ^{\prime } |
127 |
\label{eq-p-eos} \\ |
\ |
128 |
\frac{D\theta }{Dt} &=&\frac{\mathcal{Q}}{\Pi } \label{eq-p-heat} |
\frac{D\theta }{Dt} &=&\frac{\mathcal{Q}}{\Pi } \label{eq:atmos-prime} |
129 |
\end{eqnarray} |
\end{eqnarray} |