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Physics Suites
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Beginning with version 4.0, MPAS-Atmosphere introduces a new way of selecting the physics schemes to be used in a simulation. Rather than selecting individual parameterization schemes for different processes (e.g., convection, microphysics, etc.), the preferred method is to select a **suite** of parameterization schemes that have been tested together. This is done via the namelist option *config_physics_suite* in the *&physics* namelist record. Each available suites is described in the sections that follow.

It is possible to override the choice of any individual parameterization scheme through the namelist options described in `Appendix B <./appB_model_namelist.html>`_. This is useful, e.g., to disable all parameterizations except for microphysics when running some idealized simulations. See :ref:`Selecting Individual Physics Parameterizations` for details.

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mesoscale_reference Suite
=========================

The default physics suite in MPAS-Atmosphere is the *'mesoscale_reference'* suite, which contains the schemes listed in the below table. This suite has been tested for mesoscale resolutions (> 10 km cell spacing), and is not appropriate for convective-scale simulations because the Tiedtke scheme will remove convective instability before resolved-scale motions (convective cells) can respond to it.

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**The set of parameterization schemes used by the 'mesoscale_reference' physics suite**

.. csv-table::
   :header: Parameterization, Scheme
   :width: 50%

   Convection, New Tiedtke
   Microphysics, WSM6
   Land Surface, Noah
   Boundary Layer, YSU
   Surface Layer, Monin-Obukhov
   Radiation (Long-wave), RRTMG
   Radiation (Short-wave), RRTMG
   Cloud Fraction for Radiation, Xu-Randall
   Gravity Wave Drag by Orography, YSU

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convection_permitting Suite
===========================

The *'convection_permitting'* physics suite is appropriate at spatial resolutions allowing for both explicitly resolved hydrostatic and nonhydrostatic motions. It has been tested for mesh spacings from several hundred kilometers down to 3 km in MPAS. The Grell-Freitas convection scheme transitions from a conventional parameterization of deep convection at hydrostatic scales (cell spacings of several tens of kilometers) to a parameterization of precipitating shallow convection at cell spacings less than 10 km. This is the recommended suite for applications where convection-permitting meshes (dx < 10 km) are employed, including variable-resolution meshes spanning hydrostatic to nonhydrostatic resolutions.

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**The set of parameterization schemes used by the 'convection_permitting' physics suite**

.. csv-table::
   :header: Parameterization, Scheme
   :width: 50%

   Convection, Grell-Freitas
   Microphysics, Thompson (non-aerosol aware)
   Land Surface, Noah
   Boundary Layer, MYNN
   Surface Layer, MYNN
   Radiation (Long-wave), RRTMG
   Radiation (Short-wave), RRTMG
   Cloud Fraction for Radiation, Xu-Randall
   Gravity Wave Drag by Orography, YSU

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"none" Suite
============

The only other recognized physics suite in MPAS-Atmosphere is *'none'*, which sets all physics parameterizations to *off*. This is primarily intended for use with idealized simulations. For example, the idealized supercell test case makes use of the *none* suite, but with the microphysics scheme explicitly overridden:

.. code-block::
        
        config_physics_suite = 'none'
        config_microp_scheme = 'kessler'

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.. _Selecting Individual Physics Parameterizations:

Selecting Individual Physics Parameterizations
==============================================

To select or disable an individual physics parameterization, set the appropriate namelist variable to one of its possible options; possible options and their detail are given in the below table. Note that all parameterization options may be set to *'off'* to disable the parameterization of the associated process.

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**Possible options for individual physics parameterizations. Namelist variables should be added to the &physics namelist record.**

.. csv-table::
   :header: Parameterization, Namelist Variable, Possible Options, Details

   Convection, config_convection_scheme, cu_tiedtke |br| cu_ntiedtke |br| cu_kain_fritsch, Tiedtke (WRF 3.8.1) |br| New Tiedtke (WRF 4.5) |br| Modified version of scale-aware Grell-Frietas (WRF 3.6.1) |br| Kain-Fritsch (WRF 3.2.1)
   Microphysics, config_microp_scheme, mp_wsm6 |br| mp_thompson |br| mp_kessler, WSM 6-class (WRF 4.5) |br| Thompson non-aerosol aware (WRF 3.8.1) |br| Kessler
   Land Surface, config_lsm_scheme, noah, Noah (WRF 4.5)
   Boundary Layer, config_pbl_scheme, bl_ysu |br| bl_mynn, YSU (WRF 4.5) |br| MYNN (WRF 3.6.1)
   Surface Layer, config_sfclayer_scheme, sf_monin_obukhov |br| sf_mynn, Monin-Obukhov (WRF 4.5) |br| MYNN (WRF 3.6.1)
   Radiation (Long-wave), config_radt_lw_scheme, rrtmg_lw |br| cam_lw, RRTMG (WRF 3.8.1) |br| CAM (WRF 3.3.1)
   Radiation (Short-wave), config_radt_sw_scheme, rrtmg_sw |br| cam_sw, RRTMG (WRF 3.8.1) |br| CAM (WRF 3.3.1)
   Cloud Fraction for Radiation, config_radt_cld_scheme, cl_fraction |br| cld_incidence, Xu and Randall (1996) |br| 0/1 cloud fraction depending on |qc| + |qi|
   Gravity Wave Drag by Orography, config_gwdo_scheme, bl_ysu_gwdo, YSU (WRF 4.5) 


.. |qc| replace:: q\ :sub:`c`
.. |qi| replace:: q\ :sub:`i`

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

* `Next: Running the MPAS Non-hydrostatic Atmosphere Model -> <./running.html>`_

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