To learn using MOGUNTIA, we start with a simple simulation. A tracer will be emitted over the oceans. The lifetime of the tracer will be set to two years, and its global distribution will be analyzed. Also, it will be analyzed how fast a steady state distribution is obtained. This information is supplied to **MOGUNTIA** by an input file, that can be modified for your own needs.
> General information on the **MOGUNTIA** model, and how to define its input (i.e. tell the model what to simulate, what output to produce, etc.) can be found <a href="http://www.staff.science.uu.nl/~krol0101/moguntia/MANUAL/moguntia.doc/">here</a>. Important: Whenever a line in the input file starts with a **blank** (space), the line in simply skipped. This allows easy on-off switching of commands.
> * Use the menu on the left to open the precooked input file **Exercise1.in** (double click on it)
> * Try to understand its contents
To run the moguntia model with this input file, do the following:
> * select the cell below, and press **Shift-Enter**. This will connect to the so-called ***Ipython Kernel*** which sets-up interactive windows.
> * Select the input file **Exercise1.in**
> * Press the button **Run model**
This will now run the **MOGUNTIA** program. This may take a while. When the simulation is finished, the output will appear as text, or the produced output files will appear in the block **Output**.
>> Use is made of the **Python** language. **Python** can import functionality, provides plotting routines, exchange with the operating system, etc. The command below: "pm = plot_moguntia_new()", starts a model instance, and the variable **pm** carries the necessary information to the plotting program. You can analyse two runs in two seperate instances like
pm = plot_moguntia()
>> and in another Notebook cell:
pm2 = plot_moguntia()
%% Cell type:code id: tags:
``` python
%matplotlibinline
fromplot_moguntiaimport*
pm2=plot_moguntia()
```
%% Output
%% Cell type:markdown id: tags:
### Analyze the output
The next step is to analyze the output of the simulation.
> * First plot the station output by selecting output file **ex1.stations** (this is done by default)
> * Select one or more stations from the list of station names (use shift/apple/windows and control keys to select multiple files if desired)
> * Press the button **Make Plots**. A plot is created. When needed, these plots can be copied to e.g. a word-document
The emission strength defined in the input file leads to very small mole fractions in the atmosphere. For presenting the results, conversion to other units can be performed easily.
> * Convert the concentrations from **mol/mol** to parts per trillion (**ppt**) and re-plot
> * Test the use of the tick-boxes **grid** and **automatic**
The button **overplot** is of no use here. It is only useful when atmospheric measurements are available.
During the simulation other output was requested by the following lines in **Exercise1.in**:
OUTPUT MONTHLY LATLON 1000HPA
OUTPUT MONTHLY LATLON 500HPA
OUTPUT MONTHLY ZONAL_AVERAGE
These lines generated files with names **ex1ll.yyyy_mm**, and **ex1za.yyyy_mm** with **yyyy** the year, and **mm** the month. Latitude-longitude output may be requested at various pressure levels.
> * Select several input files, and press **Make Plots**
>> Note that the plotting of many latitude-longitude figures may take a considerable amount of time
> * Give all the plots a similar concentration range by deselecting **automatic**
>> With contour plots, you can manupulate the minimum, maximum, and the number of contour levels
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<b>To do</b>
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* Can you roughly explain the observed tracer distribution?
* Inspect the model wind fields in [the MOGUNTIA Wind Notebook](./MOGUNTIA-Wind.ipynb) and see if you can relate it to the modeled distribution of this tracer
