88 |
\end{itemize} |
\end{itemize} |
89 |
|
|
90 |
Key publications reporting on and charting the development of the model are |
Key publications reporting on and charting the development of the model are |
91 |
\cite{hill:95,marshall:97a,marshall:97b,adcroft:97,marshall:98,adcroft:99,hill:99,maro-eta:99}: |
\cite{hill:95,marshall:97a,marshall:97b,adcroft:97,marshall:98,adcroft:99,hill:99,maro-eta:99,adcroft:04a,adcroft:04b,marshall:04}: |
92 |
|
|
93 |
\begin{verbatim} |
\begin{verbatim} |
94 |
Hill, C. and J. Marshall, (1995) |
Hill, C. and J. Marshall, (1995) |
142 |
|
|
143 |
\section{Illustrations of the model in action} |
\section{Illustrations of the model in action} |
144 |
|
|
145 |
The MITgcm has been designed and used to model a wide range of phenomena, |
MITgcm has been designed and used to model a wide range of phenomena, |
146 |
from convection on the scale of meters in the ocean to the global pattern of |
from convection on the scale of meters in the ocean to the global pattern of |
147 |
atmospheric winds - see figure \ref{fig:all-scales}. To give a flavor of the |
atmospheric winds - see figure \ref{fig:all-scales}. To give a flavor of the |
148 |
kinds of problems the model has been used to study, we briefly describe some |
kinds of problems the model has been used to study, we briefly describe some |
409 |
\input{part1/vertcoord_figure.tex} |
\input{part1/vertcoord_figure.tex} |
410 |
%%CNHend |
%%CNHend |
411 |
|
|
412 |
\begin{equation*} |
\begin{equation} |
413 |
\frac{D\vec{\mathbf{v}_{h}}}{Dt}+\left( 2\vec{\Omega}\times \vec{\mathbf{v}} |
\frac{D\vec{\mathbf{v}_{h}}}{Dt}+\left( 2\vec{\Omega}\times \vec{\mathbf{v}} |
414 |
\right) _{h}+\mathbf{\nabla }_{h}\phi =\mathcal{F}_{\vec{\mathbf{v}_{h}}} |
\right) _{h}+\mathbf{\nabla }_{h}\phi =\mathcal{F}_{\vec{\mathbf{v}_{h}}} |
415 |
\text{ horizontal mtm} \label{eq:horizontal_mtm} |
\text{ horizontal mtm} \label{eq:horizontal_mtm} |
416 |
\end{equation*} |
\end{equation} |
417 |
|
|
418 |
\begin{equation} |
\begin{equation} |
419 |
\frac{D\dot{r}}{Dt}+\widehat{k}\cdot \left( 2\vec{\Omega}\times \vec{\mathbf{ |
\frac{D\dot{r}}{Dt}+\widehat{k}\cdot \left( 2\vec{\Omega}\times \vec{\mathbf{ |
611 |
atmosphere)} \label{eq:moving-bc-atmos} |
atmosphere)} \label{eq:moving-bc-atmos} |
612 |
\end{eqnarray} |
\end{eqnarray} |
613 |
|
|
614 |
Then the (hydrostatic form of) equations (\ref{eq:horizontal_mtm}-\ref{eq:humidity_salt}) |
Then the (hydrostatic form of) equations |
615 |
yields a consistent set of atmospheric equations which, for convenience, are written out in $p$ |
(\ref{eq:horizontal_mtm}-\ref{eq:humidity_salt}) yields a consistent |
616 |
coordinates in Appendix Atmosphere - see eqs(\ref{eq:atmos-prime}). |
set of atmospheric equations which, for convenience, are written out |
617 |
|
in $p$ coordinates in Appendix Atmosphere - see |
618 |
|
eqs(\ref{eq:atmos-prime}). |
619 |
|
|
620 |
\subsection{Ocean} |
\subsection{Ocean} |
621 |
|
|
668 |
\phi (x,y,r)=\phi _{s}(x,y)+\phi _{hyd}(x,y,r)+\phi _{nh}(x,y,r) |
\phi (x,y,r)=\phi _{s}(x,y)+\phi _{hyd}(x,y,r)+\phi _{nh}(x,y,r) |
669 |
\label{eq:phi-split} |
\label{eq:phi-split} |
670 |
\end{equation} |
\end{equation} |
671 |
and write eq(\ref{eq:incompressible}) in the form: |
%and write eq(\ref{eq:incompressible}) in the form: |
672 |
|
% ^- this eq is missing (jmc) ; replaced with: |
673 |
|
and write eq( \ref{eq:horizontal_mtm}) in the form: |
674 |
|
|
675 |
\begin{equation} |
\begin{equation} |
676 |
\frac{\partial \vec{\mathbf{v}_{h}}}{\partial t}+\mathbf{\nabla }_{h}\phi |
\frac{\partial \vec{\mathbf{v}_{h}}}{\partial t}+\mathbf{\nabla }_{h}\phi |
770 |
|
|
771 |
\subsubsection{Shallow atmosphere approximation} |
\subsubsection{Shallow atmosphere approximation} |
772 |
|
|
773 |
Most models are based on the `hydrostatic primitive equations' (HPE's) in |
Most models are based on the `hydrostatic primitive equations' (HPE's) |
774 |
which the vertical momentum equation is reduced to a statement of |
in which the vertical momentum equation is reduced to a statement of |
775 |
hydrostatic balance and the `traditional approximation' is made in which the |
hydrostatic balance and the `traditional approximation' is made in |
776 |
Coriolis force is treated approximately and the shallow atmosphere |
which the Coriolis force is treated approximately and the shallow |
777 |
approximation is made.\ The MITgcm need not make the `traditional |
atmosphere approximation is made. MITgcm need not make the |
778 |
approximation'. To be able to support consistent non-hydrostatic forms the |
`traditional approximation'. To be able to support consistent |
779 |
shallow atmosphere approximation can be relaxed - when dividing through by $ |
non-hydrostatic forms the shallow atmosphere approximation can be |
780 |
r $ in, for example, (\ref{eq:gu-speherical}), we do not replace $r$ by $a$, |
relaxed - when dividing through by $ r $ in, for example, |
781 |
the radius of the earth. |
(\ref{eq:gu-speherical}), we do not replace $r$ by $a$, the radius of |
782 |
|
the earth. |
783 |
|
|
784 |
\subsubsection{Hydrostatic and quasi-hydrostatic forms} |
\subsubsection{Hydrostatic and quasi-hydrostatic forms} |
785 |
\label{sec:hydrostatic_and_quasi-hydrostatic_forms} |
\label{sec:hydrostatic_and_quasi-hydrostatic_forms} |
816 |
|
|
817 |
\subsubsection{Non-hydrostatic and quasi-nonhydrostatic forms} |
\subsubsection{Non-hydrostatic and quasi-nonhydrostatic forms} |
818 |
|
|
819 |
The MIT model presently supports a full non-hydrostatic ocean isomorph, but |
MITgcm presently supports a full non-hydrostatic ocean isomorph, but |
820 |
only a quasi-non-hydrostatic atmospheric isomorph. |
only a quasi-non-hydrostatic atmospheric isomorph. |
821 |
|
|
822 |
\paragraph{Non-hydrostatic Ocean} |
\paragraph{Non-hydrostatic Ocean} |
1101 |
|
|
1102 |
\subsection{Vector invariant form} |
\subsection{Vector invariant form} |
1103 |
|
|
1104 |
For some purposes it is advantageous to write momentum advection in eq(\ref |
For some purposes it is advantageous to write momentum advection in |
1105 |
{eq:horizontal_mtm}) and (\ref{eq:vertical_mtm}) in the (so-called) `vector invariant' form: |
eq(\ref {eq:horizontal_mtm}) and (\ref{eq:vertical_mtm}) in the |
1106 |
|
(so-called) `vector invariant' form: |
1107 |
|
|
1108 |
\begin{equation} |
\begin{equation} |
1109 |
\frac{D\vec{\mathbf{v}}}{Dt}=\frac{\partial \vec{\mathbf{v}}}{\partial t} |
\frac{D\vec{\mathbf{v}}}{Dt}=\frac{\partial \vec{\mathbf{v}}}{\partial t} |
1214 |
surface ($\phi $ is imposed and $\omega \neq 0$). |
surface ($\phi $ is imposed and $\omega \neq 0$). |
1215 |
|
|
1216 |
\subsubsection{Splitting the geo-potential} |
\subsubsection{Splitting the geo-potential} |
1217 |
|
\label{sec:hpe-p-geo-potential-split} |
1218 |
|
|
1219 |
For the purposes of initialization and reducing round-off errors, the model |
For the purposes of initialization and reducing round-off errors, the model |
1220 |
deals with perturbations from reference (or ``standard'') profiles. For |
deals with perturbations from reference (or ``standard'') profiles. For |
1244 |
The final form of the HPE's in p coordinates is then: |
The final form of the HPE's in p coordinates is then: |
1245 |
\begin{eqnarray} |
\begin{eqnarray} |
1246 |
\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}} |
1247 |
_{h}+\mathbf{\nabla }_{p}\phi ^{\prime } &=&\vec{\mathbf{\mathcal{F}}} \label{eq:atmos-prime} \\ |
_{h}+\mathbf{\nabla }_{p}\phi ^{\prime } &=&\vec{\mathbf{\mathcal{F}}} |
1248 |
|
\label{eq:atmos-prime} \\ |
1249 |
\frac{\partial \phi ^{\prime }}{\partial p}+\alpha ^{\prime } &=&0 \\ |
\frac{\partial \phi ^{\prime }}{\partial p}+\alpha ^{\prime } &=&0 \\ |
1250 |
\mathbf{\nabla }_{p}\cdot \vec{\mathbf{v}}_{h}+\frac{\partial \omega }{ |
\mathbf{\nabla }_{p}\cdot \vec{\mathbf{v}}_{h}+\frac{\partial \omega }{ |
1251 |
\partial p} &=&0 \\ |
\partial p} &=&0 \\ |
1291 |
_{\theta ,S}\frac{Dp}{Dt} \label{EOSexpansion} |
_{\theta ,S}\frac{Dp}{Dt} \label{EOSexpansion} |
1292 |
\end{equation} |
\end{equation} |
1293 |
|
|
1294 |
Note that $\frac{\partial \rho }{\partial p}=\frac{1}{c_{s}^{2}}$ is the |
Note that $\frac{\partial \rho }{\partial p}=\frac{1}{c_{s}^{2}}$ is |
1295 |
reciprocal of the sound speed ($c_{s}$) squared. Substituting into \ref{eq-zns-cont} gives: |
the reciprocal of the sound speed ($c_{s}$) squared. Substituting into |
1296 |
|
\ref{eq-zns-cont} gives: |
1297 |
\begin{equation} |
\begin{equation} |
1298 |
\frac{1}{\rho c_{s}^{2}}\frac{Dp}{Dt}+\mathbf{\nabla }_{z}\cdot \vec{\mathbf{ |
\frac{1}{\rho c_{s}^{2}}\frac{Dp}{Dt}+\mathbf{\nabla }_{z}\cdot \vec{\mathbf{ |
1299 |
v}}+\partial _{z}w\approx 0 \label{eq-zns-pressure} |
v}}+\partial _{z}w\approx 0 \label{eq-zns-pressure} |