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

Now, let's look at other probes that can be used with 3D data - the Time/Height Display and the Grid Skew-T probe. The Time/Height display will show the variation of a field with height over time. The Grid Skew-T probe will display a model sounding generated from the data.

1. First, let's create a time/height display of relative humidity. We'll also load in an isosurface of this field for comparison. You can load in a probe without displaying the field in the main display.
   • If you have not already done so, use the Edit->Remove All Displays menu to remove the displays created in the previous exercise.
   • First, we'll load in a time/height display of relative humidity. In the Fields panel, expand the 3D grid tab. Select the relative humidity field.
   • In the Displays panel, select Isosurface (under the 3D Surface tab). Then, hold the Ctrl key down and click on Time/Height Display (Contours) (under the Probes tab) to select both. Click the Create Display button. Once the displays are created, set the isosurface value to 80% and minimize the isosurface control window.
   • Move the probe around to see how relative humidity varies with time and height at a particular location. Now, move the probe over Iowa.
   • Tilt the main display so you can see the structure of the relative humidity isosurface at the probe location, then step through the animation and compare the structure you see in the isosurface to the structure at the same time in the time/height display. How do they compare?
   • Stop the animation and return to the first time step.
2. Now, we'll create a Skew-T display of calculated model parameters.
   • In the Fields panel, expand the 3D grid tab. Expand the Derived tab and select the Sounding Data (with true winds) field. This derived quantity will show up when the grid contains temperature, dewpoint and wind fields or any of these that can be derived from others.
   • In the Displays panel, select the Grid Skew-T display. Click the Create Display button.
   • Undock the Time/Height and the Grid Skew-T displays from the Dashboard. Arrange your windows so you can see the main display, the SkewT display and the Time/Height display.
   • Now, share the probe position with the Time/Height Display. In each of the control windows, use the Edit->Sharing->Sharing On menu to turn on sharing of the probe position. Move the probe over Iowa slightly to align the two probes.
   • Step through the animation and compare model temperature and dewpoint profiles with Time/Height display. In regions of high relative humidity, the temperature and dewpoint profiler will be close together.

 

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