Input

Input

Requirements for a Simulation

To run a simulation with ICON-ART installed the first thing to prepare is the runfile. It is usually best to start with an existing and working runfile and adapt parts as needed. The runfile contains the majority of parameters to run a simulation, like the length, timesteps and grids used, as well as a variety of options for methods and parametrisations used in the model. The runfile contents are then split up in several namelists that the model reads at the beginning of a simulation. An overview of the Namelist Parameters can be found in chapter [chap:namelist].

To enable ART in an ICON simulation, the switch lart = .TRUE. has to be set in the section &run_nml. This is the global on/off switch for ICON-ART. This is how this could look like in the context of a runfile:

! run_nml: general switches ----------
&run_nml
 ltestcase = .FALSE.
 num_lev = 50
 ltransport = .TRUE.
.............

 \textcolor{red}{lart = .TRUE.}

Generally the first letters of a namelist switch refer to its type, the "l" in "lart" stands for logical, meaning it has to be either True or False. Table 1.1 lists some examples.

Some namelist switches and their data types.

namelist switch	type
lart	logical
cart_aerosol_xml	character
iart_init_aero	integer

The namelist &art_nml is used for general options of the ART simulation. To run a certain kind of simulation the according switch has to be set to .TRUE.. For Example to include a point source the switch cart_aerosol_xml has to be set to .TRUE.. This enables the inclusion of a .xml file containing additional information like location and strength of the point source. Table 1.6 contains the most important &art_nml namelist parameters and additional namelist parameters required if they are set to .TRUE..

General art_nml namelist switches and respective parameters.

Namelist parameter	Default	Description	If .TRUE. then needs
lart_chem	.FALSE.	Enables chemistry.	lart_chemtracer = .TRUE.OR lart_mecca = .TRUE.
lart_chemtracer	.FALSE.	Switch for simple OH chemistry	cart_chemtracer_xml
lart_mecca	.FALSE.	Switch for kpp chemistry	cart_mecca_xml
lart_pntSrc	.FALSE.	Enables addition of point sources	cart_pntSrc_xml
lart_aerosol	.FALSE.	Main switch for the treatment of	cart_aerosol_xml
		atmospheric aerosol.	and cart_modes_xml
lart_diag_out	.FALSE.	Enables diagnostic output fields	cart_diagnostics_xml

The reason for the use of those additional .xml files is that the ART variables (sea salt, mineral dust etc.) they contain might be different for every run which differs from the Icon Variables (Temperature, Pressure, etc.) which usually don’t change between runs. .xml files are readable for both humans and machines, which makes them easy to tweak and integrate. An Example for the contents of an .xml file adding ash particles can be seen below.

<modes>
  <aerosol id="asha">
    <kind type="char">2mom</kind>
    <d_gn type="real">1.190E-6</d_gn>
    <sigma_g type="real">1.410E+0</sigma_g>
    <rho type="real">2.600E+3</rho>
  </aerosol>
</modes>

Further .xml examples can be fount in /your_ART_Directory/runctrl_examples/xml_ctrl.

Additional Input Data

Depending on the type of simulation there might be additional input files required. These are essential files that are not contained in classical ICON initialisation data. For example for the emission of mineral dust there has to be information about the soil types supplied to the model. The additional input files should be renamed to a netcdf file and follow the naming convention shown in fig 1.1. Please note that the XXX has to be replaced by one of the indices mentionend in Table 1.3 and 1.4.

File:Figures/input-names.png

ICON-ART input file naming convention.

Additional input files for the initialisation

Species	Namelist switch	Options	XXX
Gas	iart_init_gas	0 (cold start), 5 (from file)	IGX
Aerosol	iart_init_aero	0 (cold start), 5 (from file)	IAE

Additional input files for the emissions

Type	Data	XXX
Point souces	XML-file	-
Sea salt	no extra data necessary	-
Mineral Dust	Soil Type Data	ART_STY
Biogenic VOCs	Emissions or Vegetatiom	ART_STY
Athropogenic emissions	Emission data sets	ART_BIO ART_ANT
Biomass burning	Satellite data	ART_BCF

Art namelist parameters

Name	function
General Variables
cart_input_folder	Absolute Path to ART source code
iart_init_aero	Initialization of aerosol species
iart_init_gas	Initialization of gaseous species
lart_diag_out	Enable output of diagnostic fields
lart_pntSrc	Enables point sources
lart_emiss_turbdiff	Switch if emissions should be included as surface flux condition
cart_io_suffix	user given suffix instead of automatically generated grid number
Atmospheric Chemistry
lart_chem	Main switch to enable chemistry
lart_chemtracer	Switch for parametrised chemtracers
lart_mecca	Switch for MECCA chemistry
lart_psc	Switch for computation of PSCs
cart_vortex_init_date	Date of vortex initialization
cheminit_file(max_dom)	Path to chemical initialization file
cart_cheminit_coord	Path to chemical initialization coordinate file
cart_cheminit_type	Type of chemical initialization coordinate file
XML configuration
cart_chemtracer_xml	Path to XML file for parametrised chemtracers
cart_mecca_xml	Path to XML file for MECCA tracers
cart_aerosol_xml	Path to XML file for aerosol tracers
cart_modes_xml	Path to XML file for modes
cart_pntSrc_xml	Path to XML file for point sources
cart_diagnostics_xml	Path to XML file for aerosol diagnostics
cart_emiss_xml_file	Path and file name of the xml files for emission metadata
cart_ext_data_xml	Path to XML file for metadata of datasets prescribing tracers
Atmospheric Aerosol
lart_aerosol	Main switch for the treatment of atmospheric aerosol
iart_seasalt	Treatment of sea salt aerosol
iart_dust	Treatment of mineral dust aerosol
iart_anthro	Treatment of anthropogenic aerosol
iart_fire	Treatment of wildfire aerosol
iart_volcano	Treatment of volcanic ash aerosol
iart_nonsph	Treatment of nonspherical particles
iart_pollen	Treatment of pollen
iart_radioact	Treatment of radioactive particles
cart_volcano_file	Absolute path + filename of input file for volcanoes
cart_radioact_file	Absolute path + filename of input for radioactive emissions
Feedback Processes
iart_aci_warm	Nucleation of aerosol to cloud droplets
iart_aci_cold	Nucleation of aerosol to cloud ice
iart_ari	Direct interaction of aerosol with radiation

General art_nml namelist switches and respective parameters.

Namelist parameter	Default	Description	If .TRUE. then needs
iart_modeshift	1