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\section{Illustrations of the model in action} |
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The MITgcm has been designed and used to model a vast range of phenomena, |
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from convection on the scale of meters in the ocean to the global pattern of |
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atmospheric winds - see fig.2\ref{fig:all-scales}. To give a flavor of the |
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kinds of problems the model has been used to study, we briefly describe some |
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of them here. A more detailed description of the underlying formulation, |
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numerical algorithm and implementation that lie behind these calculations is |
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given later. Indeed it is easy to reproduce the results shown here: simply |
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download the model (the minimum you need is a PC running linux, together |
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with a FORTRAN\ 77 compiler) and follow the examples. |
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\subsection{Global atmosphere: `Held-Suarez' benchmark} |
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Fig.E1a.\ref{fig:Held-Suarez} is an instaneous plot of the 500$mb$ height |
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field obtained using a 5-level version of the atmospheric pressure isomorph |
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run at 300$km$ resolution. We see fully developed baroclinic eddies along |
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the northern hemisphere storm track. There are no mountains (but you can |
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easily put them in) or land-sea contrast. The model is driven by relaxation |
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to a radiative-convective equilibrium profile, following the description set |
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out in Held and Suarez; 1994 designed to test atmospheric hydrodynamical |
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cores - there are no mountains or land-sea contrast. As decribed in Adcroft |
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(2001), `cubed sphere' is used to descretize the globe permitting a uniform |
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gridding and obviated the need to fourier filter. |
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Fig.E1b shows the 5-year mean, zonally averaged potential temperature, zonal |
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wind and meridional overturning streamfunction from the 5-level model. |
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A regular spherical lat-lon grid can also be used. |
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Results from this integration, together with a 20-level calculation, can be |
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found here - link through to channel. |
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This calculation takes 1 day of computation per year of intergation on a |
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pentium IV PC. |
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\subsection{Ocean gyres} |
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\subsection{Global ocean circulation} |
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Fig.E2a shows the pattern of ocean currents at the surface of a 4$^{\circ }$ |
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global ocean model run with 15 vertical levels. The model is driven using |
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monthly-mean winds with mixed boundary conditions on temperature and |
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salinity at the surface. Fig.E2b shows the overturning (thermohaline) |
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circulation. Lopped cells are used to represent topography on a regular $% |
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lat-lon$ grid extending from 70$^{\circ }N$ to 70$^{\circ }S$. |
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\subsection{Flow over topography} |
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\subsection{Ocean convection} |
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Fig.E3 shows convection over a slope using the non-hydrostatic ocean |
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isomorph and lopped cells to respresent topography. .....The grid resolution |
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is |
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\subsection{Boundary forced internal waves} |
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\subsection{Carbon outgassing sensitivity} |
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Fig.E4 shows.... |