==============
Idealized Case
==============

The following sub-directories can be found in your *practice_exercises/* directory:

*   **wrf_ideal_serial** : Contains all idealized cases, built for serial computation (i.e., a single processor)
*   **wrf_ideal_dm** : Contains only the 3D idealized cases, built for parallel computation (multiple processors - using the *dmpar* compile option)

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Set-up an Ideal Case
====================

#.   Move to the appropriate directory.

     .. code-block::
        :class: copyable

        cd /glade/derecho/scratch/$USER/practice_exercises/wrf_ideal_serial/test/em_case_you_desire

     Or, to run a 3D case (this will take longer than a 2d case):

     .. code-block::
        :class: copyable

        cd /glade/derecho/scratch/$USER/practice_exercises/wrf_ideal_dm/test/em_case_you_desire

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#.   Either use the default *namelist.input* to run the default case, or modify *namelist.input* for integration length, output frequency, domain size, time step, physics options, and other parameters you'd like.

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Initialization
==============

Run the ideal.exe to generate initial conditions (*wrfinput_d01*). Because idealized cases are not on a real grid, no lateral boundary file is required. Instead they use other boundary options. `See details <https://www2.mmm.ucar.edu/wrf/users/wrf_users_guide/build/html/namelist_variables.html#bdy-control>`_

|vspace|

.. note::
   The *em_fire* case requires `additional steps <https://www2.mmm.ucar.edu/wrf/site/documentation/users_guide/fire.html?highlight=em_fire#wrf-fire-in-idealized-cases>`_ before running ideal.exe.

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The way WRF was built determines the way it is run. 

*   **Serial cases** *(wrf_ideal_serial/test/em_\*)* : follow instructions for :ref:`Serial Initialization`
*   **Distributed-memory cases** *(wrf_ideal_dm/test/em_\*)* : follow instructions for :ref:`Distributed Memory Initialization`

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.. _Serial Initialization: 

Serial Initialization
---------------------

These instructions are specific to cases found in the *wrf_ideal_serial/test/em_\** directories.

Issue the following command:

.. code-block::
   :class: copyable

   ./ideal.exe

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.. _Distributed Memory Initialization:

Distributed Memory Initialization
---------------------------------

These instructions are specific to cases found in the *wrf_ideal_dm/test/em_\** directories.

Issue the following command:

.. code-block::
   :class: copyable

   qsub runideal.sh

|vspace|

.. note::
   **Only use a single processor to run ideal.exe**, even for a distributed-memory case. This is applicable on all machines - not just the NCAR HPC.

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Run WRF 
=======

The way WRF was built determines the way it is run.

*   **Serial cases** *(wrf_ideal_serial/test/em_\*)* : follow instructions for :ref:`Serial WRF`
*   **Distributed-memory cases** *(wrf_ideal_dm/test/em_\*)* : follow instructions for :ref:`Distributed Memory WRF`

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.. _Serial WRF: 

Serial WRF
----------

These instructions are specific to cases found in the *wrf_ideal_serial/test/em_\** directories.

|vspace|

When running WRF serially on NCAR's HPC, use the ``qcmd -A UMMM0017`` prefix to launch wrf.exe on a batch node, preventing login node saturation. This is specific to this tutorial and NCAR's HPC.

.. code-block::
   :class: copyable

   qcmd -A UMMM0017 -- ./wrf.exe >& wrf.out

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.. _Distributed Memory WRF:

Distributed Memory WRF
----------------------

These instructions are specific to cases found in the *wrf_ideal_dm/test/em_\** directories.

Issue the following command:

.. code-block::
   :class: copyable

   qsub runwrf.sh

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Generate Graphics
=================

If interested, `generate graphics <./graphics.html>`_ with one of the available post-processing packages.

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Return to the Practice Exercise home to page to run another exercise. 

.. rst-class:: horizbuttons-primary-m

* `Return to Practice Exercises <./practices.html>`_

.. toctree::
   :maxdepth: 4
   :hidden:

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