Help on polyphemus_display.py version 0.2

Table of content

1. Description of the zones of the dialog
   1. Path to Polyphemus
   2. Domain Description
   3. Raw Data
   4. Date
   5. Species Description
   6. Kz Parameterization
   7. Buttons
   8. Image
2. Menu Bar
   1. File
   2. Edit
   3. Computation
   4. Image
   5. Help
3. Launching a Simulation
4. Keyboard Shortcuts

Keep in mind that only a very simplified simulation can be performed with the graphical user interface.

1. Description of the Zones of the Dialog

Below is a list of all the zones of the dialog and which information to enter in them.

1.1. Path to Polyphemus

Enter the path to Polyphemus (for example ~/Polyphemus-1.1/). You can also push the button to open a path selecting dialog. This is the advised method as it is less error prone.

Please note that programs "preprocessing/ground/luc-usgs", "preprocessing/ground/roughness", "preprocessing/meteo/MM5-meteo", "preprocessing/meteo/Kz_TM", and "driver/polair3d" must be compiled before you launch a computation.

1.2 Domain Description

• x_min: minimum abscissa for the domain (in degrees);
• Delta_x: step length along x (in degrees);
• Nx: number of cells along x (integer);
• y_min: minimum ordinate for the domain (in degrees);
• Delta_y: step length along y (in degrees);
• Ny: number of cells along y (integer);
• Nz: number of levels (integer);
• levels: file defining vertical levels interface. It can either be entered in the line edit or selected by pushing the button (advised method).

1.3. Raw Data

• MM5 file raw meteorological file
• Ground data: path of the directory which contains USGS data over Europe and Africa.

You can use the raw data from the Eulerian test-case for Polyphemus.

Note that you may have to modify the values given in the section "[MM5]" of "configuration/MM5-meteo.cfg". To check the value given (projection type, time step, number of time steps, etc.), use Polyphemus/utils/MM5_var_list.

1.4. Dates

Enter the dates in format YYYY-MM-DD_HH-II-SS where YYYY is the four-digit year, MM the two-digit month (between 01 and 12), DD the two-digit day (between 01 and 31), HH the two digit hour(between 00 and 23), II the two-digit minutes (between 00 and 59) and SS the two-digit seconds (between 00 and 59). Note that the hour, minute and second are optional and have a defalut value of 0.

There are two dates given (both in that format): the beginning date and the end date for the simulation. The end date is excluded and the simulation will stop ten minutes before this date.

1.5. Species Description

• Species: name of the species considered;
• Source: File giving point emissions of the species. See 2.2 on how to modify this file;
• Initial quantity: Initial condition. Note that the initial condition is the same for the whole domain.

1.6. Kz Parameterization

You can choose between two parameterizations for vertical diffusion (for more details on those parameterizations, see AtmoData scientific documentation, available at http://www.enpc.fr/cerea/polyphemus/doc/AtmoData-1.1-scientific_doc-1.pdf):

• Louis parameterization
• Troen and Mahrt parameterization

1.7. Buttons

• Preprocessing clears the previously computed data and launches the preprocessing: computation of ground and meteorological data;
• Simulation clears the previously computed results, launches the simulation and displays the result;
• Clear clears all the line edit and set Kz parameterization to its default value ("Louis");
• Quit closes the graphical user interface.

1.8. Image

• the image itself;
• above it, the date for which the image is displayed. It is computed from the beginning date and the time step step considered (see below);
• two line edits allowing the user to specify for which time step and level to display the figure. These can only be set after computation;
• two push buttons:
  • "<<" to decrease if possible the time step displayed by one. If it is not possible, it does nothing. The line edit "Visualization for time step" and the one giving the date displayed are then updated.
  • ">>" is similar to the previous one, except it tries to increase the time step displayed.

2. Menu Bar

2.1. File

The "File" menu of the MenuBar allows you to do several things:

• Save configuration file: allows you to save all parameters of a simulation to a configuration file you can load later on.
• Load configuration file: allows you to load all simulation parameters from a configuration file. A file 'configuration.cfg' is provided to perform a simulation over Europe using raw data from the Eulerian test-case.
• Clear: clears all the line edit and set Kz parameterization to its default value ("Louis");
• Quit: closes the graphical user interface.

2.2. Edit

The "Edit" menu of the MenuBar offers several options:

• Edit source file: allows the user to open the source file with emacs, modify it and reload it if necessary. After emacs has been closed, a dialog is prompted to ask the user if they want to reload the source file. If so, they can choose the file to load. This means that you can easily modify the source file, save it under another name and load it.
• Edit levels file: similar to what is above, except the file modified is the level files. Do not forget to modify the number of levels if necessary.

2.3. Computation

The "Computation" menu of the MenuBar offers several options:

• Preprocessing: clears the previously computed data and launches the preprocessing: computation of ground and meteorological data.
• Simulation: clears the previously computed results, launches the simulation and displays the result.

2.4. IMage

The "Image" menu of the MenuBar offers several options:

• Save image: saves the image currently displayed in PNG or EPS format. A file dialog is opened to select the file under which to save.
• Forward: to decrease if possible the time step displayed by one. If it is not possible, it does nothing. The line edit "Visualization for time step" and the one giving the date displayed are then updated.
• Backward is similar to the previous one, except it tries to increase the time step displayed.

2.5. Help

• About: Opens a dialog box with some copyright information on Polyphemus and polyphemus_display.py.
• Help: Opens this help file in a dialog box.

3. Launching a Simulation

First you need to complete the dialog, that is to say enter the domain considered the date, the path to raw data...

To do so, you can use a configuration file from a previous simulation or the one which is distributed with polyphemus_display.py (file configuration.cfg). Note that the configuration file considered is not one of the configuration files needed by the programs of Polyphemus.

Once all information required are given, you can launch the preprocessing phase. It is by far the longest computation, so you should consider whether it needs being recomputed or not. Keep in mind that the results of a preprocessing are stored and are only cleared when you push the button "Preprocessing". So as long as you keep the same domain and the same date, you do not need to perform preprocessing over again. For example if you only change the species involved, the initial quantity or if you change the parameterization of vertical diffusion from Troen & Mahrt to Louis, you can launch the simulation directly.

Before launching the simulation, you may have to modify the point source file, to do so you can use the item of the MenuBar called "edit/Edit source file". You can set several sources, each in a section "[source]". Source type can be "continuous" or "puff".

To launch the simulation, push the button "Simulation". Results of previous computations are then cleared and replaced. Computation should only take a few minutes. Then an image is displayed: it is a map of concentration for the first time step and the first vertical level.

You can then modify the time step and the level for which the map is shown by changing the values in the line edits below the image or, for the time step, by pushing the buttons "<<" or ">>".

If you want to keep the results, move them elsewhere and keep with them the file saved with "File/Save configuration file" so you know what parameters you used to obtain those results and which domain and species were considered. You can also keep in the same directory the point source file and maybe the levels file.

With the graphical user interface you can only visualize the results. If you want to use other postprocessing abilities of Polyphemus, you can store the results somewhere and use AtmoPy as usual.

4. Keyboard Shortcuts