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Quick Start Guide
=================

This chapter provides MPAS-Atmosphere users with a high-level description of the general process of building and running the model. It is meant simply as a brief overview of the process, with more detailed descriptions of each step are provided in later chapters.

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Building MPAS-A
===============

**The build process generally uses the following steps.** 

#.   Build or locate an MPI implementation (MPICH, OpenMPI, MVAPICH2, MPT, etc; see `Prerequisites <./building_mpas.html#prerequisites>`_)
#.   `Build the serial netCDF library <./building_mpas.html#netcdf>`_
#.   `Build the parallel-netCDF library <./building_mpas.html#parallel-netcdf>`_
#.   `Build the Parallel I/O (PIO) library <./building_mpas.html#pio>`_
#.   (OPTIONAL) `Build the METIS package <./preparing_meshes.html#graph-partitioning-with-metis>`_
#.   `Obtain the MPAS-Model source code <../../access_code/source.html>`_
#.   `Build the init_atmosphere and atmosphere cores <./building_mpas.html#compiling-mpas>`_

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After completing these steps, the following executable files should be available in the top-level MPAS-Model directory.

*   init_atmosphere_model
*   atmosphere_model
*   build_tables

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Running an MPAS-A Global Simulation
===================================

.. note::
   The three executables (discussed in the above section) must be available prior to running the code.

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**A basic global simulation can be performed using the following steps.**

#.   Create a run directory
#.   Link the *init_atmosphere_model* and *atmosphere_model* executables to the run directory
#.   Link physics lookup tables (*src/core_atmosphere/physics/physics wrf/files/\**) to the run directory
#.   Copy the *namelist.\**, *streams.\**, and *stream_list.\** files to the run directory
#.   Edit the namelist files and the stream files appropriately (`see Running MPAS-Atmosphere <./running.html>`_)
#.   (OPTIONAL) `Prepare meshes <https://www2.mmm.ucar.edu/projects/mpas/site/documentation/users_guide/preparing_meshes.html>`_ for the simulation
#.   Run *init_atmosphere_model* to create initial conditions for `idealized cases <https://www2.mmm.ucar.edu/projects/mpas/site/documentation/users_guide/running.html#creating-idealized-initial-conditions>`_ or for `real-data cases <https://www2.mmm.ucar.edu/projects/mpas/site/documentation/users_guide/running.html#creating-real-data-initial-conditions>`_
#.   `Run "atmosphere_model" <https://www2.mmm.ucar.edu/projects/mpas/site/documentation/users_guide/running.html#running-the-model>`_ to perform model integration

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.. rst-class:: horizbuttons-next-m

* `Next: Building MPAS -> <./building_mpas.html>`_

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