10 |
|
|
11 |
The hydrostatic primitive equations (HPEs) in p-coordinates are: |
The hydrostatic primitive equations (HPEs) in p-coordinates are: |
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:atmos-mom} \\ |
\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:atmos-cont} \\ |
\partial p} &=&0 \label{eq:atmos-cont} \\ |
19 |
p\alpha &=&RT \label{eq:atmos-eos} \\ |
p\alpha &=&RT \label{eq:atmos-eos} \\ |
20 |
c_{v}\frac{DT}{Dt}+p\frac{D\alpha }{Dt} &=&\mathcal{Q} |
c_{v}\frac{DT}{Dt}+p\frac{D\alpha }{Dt} &=&\mathcal{Q} |
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 |
25 |
\mathbf{\nabla }_{p}+\omega \frac{\partial }{\partial p}$ is the total |
\mathbf{\nabla }_{p}+\omega \frac{\partial }{\partial p}$ is the total |
26 |
derivative, $f=2\Omega \sin lat$ is the Coriolis parameter, $\phi =gz$ is |
derivative, $f=2\Omega \sin lat$ is the Coriolis parameter, $\phi =gz$ is |
27 |
the geopotential, $\alpha =1/\rho $ is the specific volume, $\omega =\frac{Dp% |
the geopotential, $\alpha =1/\rho $ is the specific volume, $\omega =\frac{Dp |
28 |
}{Dt}$ is the vertical velocity in the $p-$coordinate. Equation \ref |
}{Dt}$ is the vertical velocity in the $p-$coordinate. Equation \ref |
29 |
{eq-p-firstlaw} is the first law of thermodynamics where internal energy $% |
{eq-p-firstlaw} is the first law of thermodynamics where internal energy $ |
30 |
e=c_{v}T$, $T$ is temperature, $Q$ is the rate of heating per unit mass and $% |
e=c_{v}T$, $T$ is temperature, $Q$ is the rate of heating per unit mass and $ |
31 |
p\frac{D\alpha }{Dt}$ is the work done by the fluid in compressing. |
p\frac{D\alpha }{Dt}$ is the work done by the fluid in compressing. |
32 |
|
|
33 |
It is convenient to cast the heat equation in terms of potential temperature |
It is convenient to cast the heat equation in terms of potential temperature |
36 |
\[ |
\[ |
37 |
p\frac{D\alpha }{Dt}+\alpha \frac{Dp}{Dt}=R\frac{DT}{Dt} |
p\frac{D\alpha }{Dt}+\alpha \frac{Dp}{Dt}=R\frac{DT}{Dt} |
38 |
\] |
\] |
39 |
which, when added to the heat equation \ref{eq-p-firstlaw} and using $% |
which, when added to the heat equation \ref{eq-p-firstlaw} and using $ |
40 |
c_{p}=c_{v}+R$, gives: |
c_{p}=c_{v}+R$, gives: |
41 |
\begin{equation} |
\begin{equation} |
42 |
c_{p}\frac{DT}{Dt}-\alpha \frac{Dp}{Dt}=\mathcal{Q} |
c_{p}\frac{DT}{Dt}-\alpha \frac{Dp}{Dt}=\mathcal{Q} |
55 |
the Exner function: |
the Exner function: |
56 |
\[ |
\[ |
57 |
c_{p}T=\Pi \theta \;\;;\;\;\frac{\partial \Pi }{\partial p}=\frac{\kappa \Pi |
c_{p}T=\Pi \theta \;\;;\;\;\frac{\partial \Pi }{\partial p}=\frac{\kappa \Pi |
58 |
}{p}\;\;;\;\;\alpha =\frac{\kappa \Pi \theta }{p}=\frac{\partial \ \Pi }{% |
}{p}\;\;;\;\;\alpha =\frac{\kappa \Pi \theta }{p}=\frac{\partial \ \Pi }{ |
59 |
\partial p}\theta \;\;;\;\;\frac{D\Pi }{Dt}=\frac{\partial \Pi }{\partial p}% |
\partial p}\theta \;\;;\;\;\frac{D\Pi }{Dt}=\frac{\partial \Pi }{\partial p} |
60 |
\frac{Dp}{Dt} |
\frac{Dp}{Dt} |
61 |
\] |
\] |
62 |
where $b=\frac{\partial \ \Pi }{\partial p}\theta $ is the buoyancy. |
where $b=\frac{\partial \ \Pi }{\partial p}\theta $ is the buoyancy. |
72 |
\end{equation} |
\end{equation} |
73 |
which is in conservative form. |
which is in conservative form. |
74 |
|
|
75 |
For convenience in the model we prefer to step forward (\ref{theta-equation}% |
For convenience in the model we prefer to step forward (\ref{theta-equation} |
76 |
) rather than (\ref{eq-p-firstlaw}). |
) rather than (\ref{eq-p-firstlaw}). |
77 |
|
|
78 |
\subsubsection{Boundary conditions} |
\subsubsection{Boundary conditions} |
116 |
|
|
117 |
The final form of the HPE's in p coordinates is then: |
The final form of the HPE's in p coordinates is then: |
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 |
\\ |
\\ |
122 |
\frac{\partial \phi ^{\prime }}{\partial p}+\alpha ^{\prime } &=&0 |
\frac{\partial \phi ^{\prime }}{\partial p}+\alpha ^{\prime } &=&0 |
123 |
\\ |
\\ |
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 \\ |
\partial p} &=&0 \\ |
126 |
\frac{\partial \Pi }{\partial p}\theta ^{\prime } &=&\alpha ^{\prime } |
\frac{\partial \Pi }{\partial p}\theta ^{\prime } &=&\alpha ^{\prime } |
127 |
\\ |
\\ |