ICON-ART — ICOsahedral Nonhydrostatic model with Aerosols and Reactive Trace gases
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Overview
========

ICON-ART is a state-of-the-science seamless model system for the whole
atmosphere developed jointly by the German Weather Service (DWD), the
Karlsruhe Institute of Technology (KIT), and the Max Planck Institute for
Meteorology (MPI-M).

`ICON <https://code.mpimet.mpg.de/projects/iconpublic>`__ (ICOsahedral
Nonhydrostatic) is a non-hydrostatic global weather and climate model that
solves the full three-dimensional compressible Navier-Stokes equations on an
unstructured icosahedral grid.  The model supports seamless predictions from
convection-permitting regional scales to global scales.

`ART <https://www.imk-tro.kit.edu/english/5925.php>`__ (Aerosols and Reactive
Trace gases) is a sub-module of ICON that extends it with:

* emission processing,
* tracer transport,
* gas-phase chemistry,
* aerosol dynamics in the troposphere and stratosphere.

Key references
==============

* **Zängl et al. (2015)** — the ICON dynamical core:
  *The ICON (Icosahedral Non-hydrostatic) modelling framework of DWD and MPI-M:
  Description of the non-hydrostatic dynamical core*, Q. J. R. Meteorol. Soc.,
  141, 563–579,
  `doi:10.1002/qj.2378 <https://doi.org/10.1002/qj.2378>`__.

* **Schröter et al. (2018)** — the ART chemistry and aerosol module:
  *ICON-ART 2.1: a flexible tracer framework and its application for
  composition studies in numerical weather forecasting and climate simulations*,
  Geosci. Model Dev., 11, 4043–4068,
  `doi:10.5194/gmd-11-4043-2018 <https://doi.org/10.5194/gmd-11-4043-2018>`__.

* **Thanwerdas et al. (2025)** — CIF integration and EnSRF validation:
  *Improving the ensemble square root filter (EnSRF) in the Community
  Inversion Framework: a case study with ICON-ART 2024.01*,
  Geosci. Model Dev., 18, 1505–1544,
  `doi:10.5194/gmd-18-1505-2025 <https://doi.org/10.5194/gmd-18-1505-2025>`__.

Official resources
==================

* `ICON public code repository (MPI-M GitLab) <https://code.mpimet.mpg.de/projects/iconpublic>`__
* `ICON documentation wiki <https://code.mpimet.mpg.de/projects/iconpublic/wiki/Documentation>`__
* `ICON-ART at KIT IMK-TRO <https://www.imk-tro.kit.edu/english/5925.php>`__

CIF integration
===============

The CIF ICON-ART plugin is located under
:doc:`pycif.plugins.models.iconart </documentation/plugins/models/iconart>`.

Example runscripts for ICON-ART with CIF are available in
`the CIF GitLab repository <https://gitlab.in2p3.fr/satinv/cif/-/tree/devel/examples/iconart>`__.

.. note::

    The ICON-ART plugin has been used to run CH₄ and N₂O inversions with the
    CIF EnSRF mode.  It supports the ICON icosahedral unstructured grid and
    uses the ICON namelist system for configuration.