View LPT in 2DH View

To view particles in the 2DH View, click add a new layer to add the LPT / Oilspill layer (Figure 1). More detail on adding a new layer is described in Add a New Model Layer.

To demonstrate how particles can be viewed, we will use the demo model downloaded from the EEMS website as an example. This model consists of a rectangular domain with a flat bottom, an open boundary to the east, and a flow boundary along the southwest edge. U component masks were inserted to demonstrate the functionality of the LPT computations when masks are used (Figure 2).

Figure 1.   Add LPT layer.

Figure 2.   Harbor_U grid showing the masks, boundaries, and initial particle locations.

The model represents the vertical component as a depth-averaged system with one sigma layer. The depths of the five drifters are initialized at specified depths.

The results of the simulations are presented in Figure 3, showing the trajectories of the five drifters over 12 hours.

Figure 4 shows the particle tracks colored by elevation and with random walk applied. Even though there was no vertical component, the tidal range is seen to result in changing particle elevations.

Figure 3.   Harbor_U: Trajectories of 5 drifters over 12 hours (no random walk).

Figure 4.  Harbor_U: Trajectories of 5 drifters over 12 hours (random walk).

Options from RMC on the LPT layer

A number of options from RMC on the selected LPT layer in the Layer Control is shown in Figure 5. These options are described below. 

Figure 5.  LPT layer: RMC's options.

Properties: Set the display properties for the particles such as color, shape, and when they begin and stop appearing.

Figure 6 shows properties settings for the general options, and Figure 7 shows properties settings for the particles group options.

Figure 6.  LPT Properties: General Options.

Figure 7.  LPT Properties: Particle Group Options.

Zoom to Layer: Zoom the view to the selected layer

Export to: This option exports the position of drifters at a specific snapshot. After selecting this option, the Save Drifter Positions form is used to select a folder to store the drifters file (file extension is *.txt). By default, the file will be saved in the #analysis folder. Enter the filename, and click the Save button (Figure 8). Go to the #analysis of the model and open the drifters' text file to see the file format (Figure 9).

Figure 8. Save Drifter Positions form.

Figure 9. Drifters file format.

Export All Drifters to: This option allows exporting the position of all drifters with the entire timing of model output. After selecting this option, the Save Drifter Positions form is used to select a folder to store the drifters file (file extension is *.txt). By default, the file will be saved in the #analysis folder. Enter the filename, and click the Save button (Figure 10). Go to the #analysis of the model and open the drifters' text file to see the file format (Figure 11), in which Julian time (Day) is the time column; X1 and Y1 are the coordinates of drifter 1, and Z1 is the depth of drifter 1, and so on.

Figure 10. Export all drifters.

Figure 11. Drifters file format.

Edit: After selecting this option, the 2DH View Option will be displayed, as shown in Figure 12.

Figure 12. 2DH View Option.

Remove: Delete the LPT layer from the Layer Control

To export the selected drifter, select the Particles layer, enable the cursor then click on a specific drifter on the 2DH View. The particle ID will be shown in the yellow box. RMC on that drifter then select Export Selected Drifter as shown in Figure 13. Select that option, and the Save Drifter Positions form can be used to select a folder to store the drifters file (file extension is *.txt). By default, the file will be saved in the #analysis folder. Enter the filename, and click the Save button (Figure 14). Go to the #analysis of the model and open the drifters' text file to see the file format (Figure 15). The file format is similar to the file format shown in Figure 11, the difference is this file is for one selected drifter.

Figure 13. 2DH View Option.

Figure 14. Export all drifters.

Figure 15. Drifters file format.