Download CANSARP 5.0 User Manual - FTP Directory Listing

Chapter 9: Environmental Data: Current Data and Models
9.11.2 The Tidal Models tab of the Current Manager – Overriding the Default Grid
There is usually no need to specify which tidal grids to use in drift calculations; CANSARP
automatically selects tidal grids depending on the location of search objects and the time period
of the drift. You may, however, override the default selection by choosing another on the Tidal
Currents tab of the Current Manager:
Figure 9.20: The Current
Manager's Tidal Models
tab, with tidal grids menu
expanded
To use an alternate tidal grid in place of the default, first select the Override Default Tidal Grid
With: button to activate the drop down menu to its right. When the menu becomes active , click
on the down arrow to expand the drop down menu as shown in and then select the grid you wish
to use. Only those grids with seasonal variations are listed; although there are multiple Bay of
Fundy tidal grids, only one grid applies at any given longitude and latitude regardless of season.
If the selected grid covers the geographic region of the drift, it will be used instead of the default
selection; otherwise the default will still be used. For example, if the search objects are located
off the east coast of Vancouver Island and a Bay of Fundy tidal grid is selected, CANSARP will
continue to use the GF7 grid appropriate for the time of year.
To revert to using the internally selected grid, select the Use Defaults radio button. This will grey
out the Override Default Tidal Grid With: field, indicating that the tidal grid displayed in the field
is no longer overriding the default selection.
9.11.2.1 Viewing Tidal Grids in the Current Manager
You may view the tidal grid diagrams on the Tidal Currents tab of the Current Manager without
placing search objects within the tidal regions. To do so, simply select the grid you wish to
display from the View Tide Grids menu as shown in Figure 9.10.
111