.. _snowstorm_parametrizations:

SnowStorm Parametrizations
==========================

All SnowStorm parametrizations are defined as classes inheriting from the :py:class:`Parametrization` base class and need to have a :py:meth:`transform` method.
For details on how to use/apply parametrizations/perturbers in simulation refer to :ref:`SnowsStorm Configuration <snowstorm_configuration>`.

The following list is an overview of all parametrizations currently implemented:


Absorption
----------

* Identifier: ``Absorption``

  This parametrization scales the overall (global) ice absorption coefficient with reference to the baseline ice model.


AnisotropyScale
---------------

* Identifier: ``AnisotropyScale``

  This parametrization scales the ice anisotropy strength.

.. note::
    It does (and can) **not** change the direction of the anisotropy axis but change the strength of the ice anisotropy only!


DOMEfficiency
-------------

* Identifier: ``AnisotropyScale``

  This parametrization scales the DOMEfficiency of all DOMs with a factor. The reference DOMEfficiency is taken from the baseline ice model specified in the SnowStorm configuration file.


HoleIce
-------

The :wiki:`MSU Forward HoleIce wikipage <MSU_Forward_Hole_Ice>` for more details on the holeIce model.

For SnowStorm, there are two parametrizations for two different HoleIce models/parametrizations:

.. note::
   Both HoleIce models depend on two parameters! Make sure to specify a sampling distribution for both, see :ref:`SnowStorm  Configuration <snowstorm_configuration>` for more details.


MSU HoleIce
^^^^^^^^^^^

* Identifier: ``HoleIceForward_MSU``

  Please refer to the :wiki:`MSU Forward HoleIce wikipage <MSU_Forward_Hole_Ice>` for more details on the MSU HoleIce model.


Unified HoleIce
^^^^^^^^^^^^^^^

* Identifier: ``HoleIceForward_Unified``

  More information of the unified angular acceptance model (developed by Philipp Eller) can be found on its `GitHub <https://github.com/philippeller/angular_acceptance>`_ page.


IceWavePlusModes
----------------

The IceWavePlusModes scales the ice absorption and scattering coefficients not globally but depth depend using the ``icewave`` ice model.
To reduce the number of parameters (the ice is split in 10m thick layers, each with independent absorption/scattering), it uses a Fourier analysis.
More details on this ice model and the Fourier decomposition can be found in the :arxiv:`SnowStorm paper <1909.01530>`.

Scattering
----------

* Identifier: ``Scattering``

  This parametrization scales the overall (global) ice scattering coefficient with reference to the baseline ice model.