manual/s_overview/illustration.tex

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\section{Illustrations of the model in action}

The MITgcm has been designed and used to model a vast range of phenomena,
from convection on the scale of meters in the ocean to the global pattern of
atmospheric winds - see fig.2\ref{fig:all-scales}. To give a flavor of the
kinds of problems the model has been used to study, we briefly describe some
of them here. A more detailed description of the underlying formulation,
numerical algorithm and implementation that lie behind these calculations is
given later. Indeed it is easy to reproduce the results shown here: simply
download the model (the minimum you need is a PC running linux, together
with a FORTRAN\ 77 compiler) and follow the examples.

\subsection{Global atmosphere: `Held-Suarez' benchmark}

Fig.E1a.\ref{fig:Held-Suarez} is an instaneous plot of the 500$mb$ height
field obtained using a 5-level version of the atmospheric pressure isomorph
run at 300$km$ resolution. We see fully developed baroclinic eddies along
the northern hemisphere storm track. There are no mountains (but you can
easily put them in) or land-sea contrast. The model is driven by relaxation
to a radiative-convective equilibrium profile, following the description set
out in Held and Suarez; 1994 designed to test atmospheric hydrodynamical
cores - there are no mountains or land-sea contrast. As decribed in Adcroft
(2001), `cubed sphere' is used to descretize the globe permitting a uniform
gridding and obviated the need to fourier filter.

Fig.E1b shows the 5-year mean, zonally averaged potential temperature, zonal
wind and meridional overturning streamfunction from the 5-level model.

A regular spherical lat-lon grid can also be used.

Results from this integration, together with a 20-level calculation, can be
found here - link through to channel.

This calculation takes 1 day of computation per year of intergation on a
pentium IV PC.

\subsection{Ocean gyres}

\subsection{Global ocean circulation}

Fig.E2a shows the pattern of ocean currents at the surface of a 4$^{\circ }$
global ocean model run with 15 vertical levels. The model is driven using
monthly-mean winds with mixed boundary conditions on temperature and
salinity at the surface. Fig.E2b shows the overturning (thermohaline)
circulation. Lopped cells are used to represent topography on a regular $
lat-lon$ grid extending from 70$^{\circ }N$ to 70$^{\circ }S$.

\subsection{Flow over topography}

\subsection{Ocean convection}

Fig.E3 shows convection over a slope using the non-hydrostatic ocean
isomorph and lopped cells to respresent topography. .....The grid resolution
is

\subsection{Boundary forced internal waves}

\subsection{Carbon outgassing sensitivity}

Fig.E4 shows....
1	cnh	1.3	% $Header: /u/u0/gcmpack/mitgcmdoc/part1/illustration.tex,v 1.2 2001/09/27 01:57:17 cnh Exp $
2	cnh	1.2	% $Name: $
3	adcroft	1.1
4			\section{Illustrations of the model in action}
5
6			The MITgcm has been designed and used to model a vast range of phenomena,
7			from convection on the scale of meters in the ocean to the global pattern of
8			atmospheric winds - see fig.2\ref{fig:all-scales}. To give a flavor of the
9			kinds of problems the model has been used to study, we briefly describe some
10			of them here. A more detailed description of the underlying formulation,
11			numerical algorithm and implementation that lie behind these calculations is
12			given later. Indeed it is easy to reproduce the results shown here: simply
13			download the model (the minimum you need is a PC running linux, together
14			with a FORTRAN\ 77 compiler) and follow the examples.
15
16			\subsection{Global atmosphere: `Held-Suarez' benchmark}
17
18			Fig.E1a.\ref{fig:Held-Suarez} is an instaneous plot of the 500$mb$ height
19			field obtained using a 5-level version of the atmospheric pressure isomorph
20			run at 300$km$ resolution. We see fully developed baroclinic eddies along
21			the northern hemisphere storm track. There are no mountains (but you can
22			easily put them in) or land-sea contrast. The model is driven by relaxation
23			to a radiative-convective equilibrium profile, following the description set
24			out in Held and Suarez; 1994 designed to test atmospheric hydrodynamical
25			cores - there are no mountains or land-sea contrast. As decribed in Adcroft
26			(2001), `cubed sphere' is used to descretize the globe permitting a uniform
27			gridding and obviated the need to fourier filter.
28
29			Fig.E1b shows the 5-year mean, zonally averaged potential temperature, zonal
30			wind and meridional overturning streamfunction from the 5-level model.
31
32			A regular spherical lat-lon grid can also be used.
33
34			Results from this integration, together with a 20-level calculation, can be
35			found here - link through to channel.
36
37			This calculation takes 1 day of computation per year of intergation on a
38			pentium IV PC.
39
40			\subsection{Ocean gyres}
41
42			\subsection{Global ocean circulation}
43
44			Fig.E2a shows the pattern of ocean currents at the surface of a 4$^{\circ }$
45			global ocean model run with 15 vertical levels. The model is driven using
46			monthly-mean winds with mixed boundary conditions on temperature and
47			salinity at the surface. Fig.E2b shows the overturning (thermohaline)
48	cnh	1.2	circulation. Lopped cells are used to represent topography on a regular $
49	adcroft	1.1	lat-lon$ grid extending from 70$^{\circ }N$ to 70$^{\circ }S$.
50
51			\subsection{Flow over topography}
52
53			\subsection{Ocean convection}
54
55			Fig.E3 shows convection over a slope using the non-hydrostatic ocean
56			isomorph and lopped cells to respresent topography. .....The grid resolution
57			is
58
59			\subsection{Boundary forced internal waves}
60
61			\subsection{Carbon outgassing sensitivity}
62
63			Fig.E4 shows....