Simulating a Point Source

In this Tutorial, the steps to simulate a Volcanic Eruption via a point source are given.

Setting up ICON-ART

The first thing to do is having a working installation of ICON-art. To check if your icon version has been built correctly, you can check if

your_icon_folder/bin/icon.exe 

exists.

Setting up Directories

Now a directory structure has to be set up. Usually the following directories are used:

• Working Directory: Here the files that are needed for an individual run are saved. This usually includes the runscript and the relevant .xml files.
• Icon Code directory: This is where the Icon code is stored.
• External Data directory: Here external files which are needed for a run are stored. For example, to parametrize the optical properties of clouds a files like ECHAM6_CldOptProps.nc is used. These files of course can be switched out for others, however in most applications the same ones are used. A list of the used files is given in the Runscript, which then creates a link of these files in the Output directory.
• Output directory: This is where the new Simulation data will be stored. Since most of the time large amounts of data are produced, this is stored in the work or scratch partitions on most HPC Systems. The Namelists produced by the runfile are also stored here.

Setting up the Runscript

The function of the runscript is to set up the directory structure,link the relevant files and create the namelists.

Setting up the .xml's

Here the .xml

pntSRC.xml

is set up. It contains all the necessary information to describe the emission of the here defined aerosols into the atmosphere. The following information is contained:

• where is the Pointsource
• when is it emitting
• what substances are emitted
• how much of each substance is emitted
• what size are the emitted substances (median and standard deviation)

This can be adapted as needed.

In this example, the Raikoke eruption on 21. of June 2019 is Simulated, as can be seen in the following .xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE tracers SYSTEM "sources_selTrnsp.dtd">

<sources>
  <pntSrc id="Raikoke-SO2">
    <lon type="real">153.24</lon>
    <lat type="real">49.29</lat>
    <substance type="char">TRSO2</substance>
    <source_strength type="real">46300.0</source_strength>
    <height type="real">14000</height>
    <height_bot type="real">600</height_bot>
    <unit type="char">kg s-1</unit>
    <startTime type="char">2019-06-21T13:00:00</startTime>
    <endTime type="char">2019-06-21T22:00:00</endTime>
  </pntSrc>
  <pntSrc id="Raikoke-ashacc">
    <lon type="real">153.24</lon>
    <lat type="real">49.29</lat>
    <substance type="char">ash_insol_acc</substance>
    <dg3_emiss type="real">0.8E-6</dg3_emiss>
    <sigma_emiss type="real">1.4</sigma_emiss>
    <source_strength type="real">19700.0</source_strength>
    <height type="real">14000</height>
    <height_bot type="real">600</height_bot>
    <unit type="char">kg s-1</unit>
    <startTime type="char">2019-06-21T13:00:00</startTime>
    <endTime type="char">2019-06-21T22:00:00</endTime>
  </pntSrc>
  <pntSrc id="Raikoke-ashcoa">
    <lon type="real">153.24</lon>
    <lat type="real">49.29</lat>
    <substance type="char">ash_insol_coa</substance>
    <dg3_emiss type="real">2.98E-6</dg3_emiss>
    <sigma_emiss type="real">1.4</sigma_emiss> 
    <source_strength type="real">19700.0</source_strength>
    <height type="real">14000</height>
    <height_bot type="real">600</height_bot>
    <unit type="char">kg s-1</unit>
    <startTime type="char">2019-06-21T13:00:00</startTime>
    <endTime type="char">2019-06-21T22:00:00</endTime>
  </pntSrc>
  <pntSrc id="Raikoke-ashgiant">
    <lon type="real">153.24</lon>
    <lat type="real">49.29</lat>
    <substance type="char">ash_giant</substance>
    <dg3_emiss type="real">11.35E-6</dg3_emiss>
    <sigma_emiss type="real">1.4</sigma_emiss>
    <source_strength type="real">19700.0</source_strength>
    <height type="real">14000</height>
    <height_bot type="real">600</height_bot>
    <unit type="char">kg s-1</unit>
    <startTime type="char">2019-06-21T13:00:00</startTime>
    <endTime type="char">2019-06-21T22:00:00</endTime>
  </pntSrc>
</sources>