Unidata

1. First, let's create a display of wind barbs with geopotential heights.
   • Clear out any existing displays.
   • In the Field Selector's Data Sources panel, select the NCEP Model Data ETA data source.
   • In the Fields panel, expand the 3D grid tab. Select the geopotential height, the Contour Plan View display and set the Level to be 500 hectopascals, then click the Create Display button.
   • In the Fields panel, expand the 3D grid tab. Scroll down to the Derived tab and expand that. Select the Flow Vectors (from GridRelative_u & GridRelative_v) field.
   • In the Displays panel, select Wind Barb Plan View, in the Level tab, select 500 hectopascals, then click the Create Display button.
   • The display is pretty cluttered. You can change the skip interval to declutter the display. Try various intervals.
   • Toggle between vectors and streamlines and play around with the streamline density slider.
   • Link the two displays by selecting the Edit->Sharing->Sharing On menu.
   • Change the level and see how the pattern changes.
   • Turn on the time animation.
2. Now, let's add a cross section display of wind vectors
   • Stop the time animation.
   • In the Field Selector's Fields panel, select the Flow Vectors (from GridRelative_u & GridRelative_v) field.
   • In the Displays panel of the Field Selector, select Vector Cross Section and then click the Create Display button.
   • Move the cross section around and see how the flow changes.
   • Start the animation.

Unidata IDV Workshop for version 3.0u2 > Accessing and Displaying Data > Working with Gridded Data