:orphan:

Physics Suites
==============

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Physics Contents
----------------

`WRF Physics Overview`_ |br|
`Cumulus Parameterization`_ |br|
Microphysics_ |br|
Radiation_ |br|
`Planetary Boundary Layer (PBL) Physics`_ |br|
`Surface Physics`_ |br|
`Using Physics Suites`_ |br|
`Physics Options for Specific Applications`_

.. _`WRF Physics Overview`: physics.html
.. _`Cumulus Parameterization`: cumulus.html
.. _Microphysics: microphysics.html
.. _Radiation: radiation.html
.. _`Planetary Boundary Layer (PBL) Physics`: pbl.html
.. _`Surface Physics`: surface.html
.. _`Using Physics Suites`: phys_suites.html
.. _`Physics Options for Specific Applications`: specific_applications.html

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Using Physics Suites
--------------------

A WRF physics suite is a set of physics options that performs well for a given application and is supported by a sponsoring group. Suites may offer guidance to users in applying WRF, improve understanding of model performance, and facilitate model advancement.  

When running WRF, a suite of physics schemes can be set by using the **physics_suite** namelist option. The physics options covered by this suite specification are: 
    
    mp_physics |br|
    cu_physics |br|
    bl_pbl_physics |br|
    sf_sfclay_physics |br|
    sf_surface_physics |br|
    ra_sw_physics |br|
    ra_lw_physics
    
There are currently 2 available approved physics suite options: the NCAR Convection-permitting Suite (CONUS), and the NCAR Tropical Suite (tropical) that can be specified in the &physics section of the namelist.input file. By simply setting the "physics_suite" namelist parameter, the included physics schemes are assumed and, therefore, the specific schemes (e.g., mp_physics, cu_physics, etc.) do not need to be set. These two suites consist of a combination of physics options that have been highly tested and have shown reasonable results.

A summary of the physics schemes used in the simulation are printed to the WRF output log (e.g., rsl.out.0000). 

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NCAR Convection-permitting Suite
--------------------------------

**physics_suite='CONUS'** |br|

Real-time forecasting focused on convective weather over the contiguous U.S.

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.. csv-table:: 
   :widths: 70, 50, 50  
   :align: left 
   :header: "Physics Type", "Scheme Name", "Namelist Option"

   Microphysics, Thompson, mp_physics=8 
   Cumulus, Tiedtke, cu_physics=6
   Longwave Radiation, RRTMG, ra_lw_physics=4
   Shortwave Radiation, RRTMG, ra_sw_physics=4
   PBL, MYJ, bl_pbl_physics=2
   Surface Layer, MYJ, sf_sfclay_physics=2
   LSM, Noah, sf_surface_physics=2

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    .. note::
       See `NCAR Convection-permitting Physics Suite for WRF` for additional details.

.. _`NCAR Convection-permitting Physics Suite for WRF`: https://www2.mmm.ucar.edu/wrf/users/physics/ncar_convection_suite.php

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NCAR Tropical Suite
-------------------

**physics_suite='tropical'** |br|

Real-Time forecasting focused on tropical storms and tropical convection

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    .. note::
       This is the same as the "mesoscale_reference" suite in the MPAS model.

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.. csv-table:: 
   :widths: 70, 50, 50  
   :align: left 
   :header: "Physics Type", "Scheme Name", "Namelist Option"

   Microphysics, WSM6, mp_physics=6 
   Cumulus, New Tiedtke, cu_physics=16
   Longwave Radiation, RRTMG, ra_lw_physics=4
   Shortwave Radiation, RRTMG, ra_sw_physics=4
   PBL, YSU, bl_pbl_physics=1
   Surface Layer, MM5, sf_sfclay_physics=91
   LSM, Noah, sf_surface_physics=2

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    .. note::
       See `NCAR Tropical Physics Suite for WRF` for additional details.

.. _`NCAR Tropical Physics Suite for WRF`: https://www2.mmm.ucar.edu/wrf/users/physics/ncar_tropical_suite.php 

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Overriding Physics Suite Options
--------------------------------

To override any of the above options, simply add that particular parameter to the namelist. 

**Example 1** : You wish to use the CONUS suite but would like to turn off cu_physics for domain 3 (note: a setting of "-1" means the default setting is used):


.. code-block::

   physics_suite = 'CONUS' |br|
   cu_physics = -1, -1, 0

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**Example 2** : You wish to use the CONUS suite but would like to use a different cu_physics option, and to turn cu_physics off for domain 3:


.. code-block::

   physics_suite = 'CONUS'
   cu_physics = 2, 2, 0

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.. image:: images/blank_image.png
    :width: 800px
    :height: 200px

Next section: `Physics Options for Specific Applications`_

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.. _`Physics Options for Specific Applications`: specific_applications.html