[IDV #IAQ-137060]: Isentropic potential vorticity

Hi Andy-

> Thanks, Don. I am still an IDV neophyte and not clear on what can be done and 
> what can't.

No problem. 

> In the "Quicklinks" there is an IPV bundle set up to work with NAM gridded 
> data, but I see that IPV isosurfaces are plotted at their geopotential 
> height, not their potential temperature. 

Correct.

>I assume that this same plot format can be done with GFS data, but have not 
>yet managed to get the right sequence of "clicks". Give me a couple of more 
>tries and hopefully I will have it.

When you load in the GFS data, expand the 3D grids->Derived choice and you 
should see
Isentropic Potential Vorticity (from Temperature & absvort) listed.  Select 3D 
Surface->
Isosurface for your display.  It will take a while to compute the values since 
it has to
compute it for the entire volume.  You might want to do one timestep first to 
make sure
it works for you.

> Also in the "Quicklinks", there is a thetae-3D bundle. Theta-e is plotted as 
> an isosurface, but the vertical coordinate is unclear. Is it geopotential 
> height?

It's really altitude of the pressure values in the standard atmosphere.  The 
IDV maps 
the pressure vertical coordinate to the height in the standard atmosphere.

> Plotting various parameters on isentropic surfaces (potential vorticity, 
> winds, water vapor mixing ratio, Montgomery stream function, etc.) would be 
> very useful pedagogically. I suppose if it was easy, it would already be an 
> option in IDV.

It's on our list of things to do.  Again, if you have the isentropic GEMPAK 
grids you can do 
this as 2D plots where we do a linear scaling of the theta vertical coordiante 
to altitude
to place it in the 3D box.  The GEMPAK  GDVINT program does not create a HGHT 
variable,
but if it did, you could use the 2D field over topography to display the true 
location
in 3D space.

Don Murray

> -----Original Message-----
> From: Unidata IDV Support [mailto:address@hidden]
> Sent: Tuesday, March 03, 2009 7:23 AM
> To: Detwiler, Andrew G.
> Cc: address@hidden
> Subject: [IDV #IAQ-137060]: Isentropic potential vorticity
> 
> Hi Andy-
> 
> > Full Name: Andrew Detwiler
> > Email Address: address@hidden
> > Organization: SDSMT
> > Package Version: 2.6u2 build date:2009-02-12 20:31 UTC
> > Operating System: Windows XP
> > Hardware: Java: home: C:\Program Files\IDV_2.6u2\jre version: 1.6.0_11 
> > j3d:1.5.2 fcs (build4)
> > Description of problem: Creating display: Isosurface colored by another 
> > parameter
> > No data selected
> >
> > I am trying to plot potential vorticity surfaces and isentropi potential 
> > vorticity on a constant potential temperature surface. Atthe moment, I am 
> > having little success with either. Can you tell me what plots to select 
> > from the standard IDV plot tree menu? Or are these plots things that must 
> > be programmed individually by the user?
> 
> If you are trying to plot them on the isosurface of the constant potential 
> temperature,
> there is no way to do that currently.  If you have a GEMPAK grid file with the
> data in isentropic coordinates, then you plot them as 2D fields.
> 
> Don Murray
> > - Andy Detwiler
> >
> > ******************
> > Stack trace:
> > java.lang.IllegalStateException: No data selected
> > at 
> > ucar.unidata.idv.ui.IdvUIManager.selectDataChoices(IdvUIManager.java:5234)
> > at 
> > ucar.unidata.idv.IntegratedDataViewer.selectDataChoices(IntegratedDataViewer.java:987)
> > at 
> > ucar.unidata.data.DerivedDataChoice.collectOperands(DerivedDataChoice.java:549)
> > at ucar.unidata.data.DerivedDataChoice.getData(DerivedDataChoice.java:710)
> > at ucar.unidata.data.DataChoice.getData(DataChoice.java:633)
> > at ucar.unidata.data.DataInstance.getData(DataInstance.java:239)
> > at ucar.unidata.data.DataInstance.getData(DataInstance.java:203)
> > at ucar.unidata.data.grid.GridDataInstance.init(GridDataInstance.java:204)
> > at ucar.unidata.data.grid.GridDataInstance.<init>(GridDataInstance.java:161)
> > at ucar.unidata.data.grid.GridDataInstance.<init>(GridDataInstance.java:142)
> > at 
> > ucar.unidata.idv.control.GridDisplayControl.doMakeDataInstance(GridDisplayControl.java:298)
> > at 
> > ucar.unidata.idv.control.DisplayControlImpl.initializeDataInstance(DisplayControlImpl.java:2949)
> > at 
> > ucar.unidata.idv.control.DisplayControlImpl.setData(DisplayControlImpl.java:2931)
> > at 
> > ucar.unidata.idv.control.ThreeDSurfaceControl.setData(ThreeDSurfaceControl.java:248)
> > at 
> > ucar.unidata.idv.control.ThreeDSurfaceControl.init(ThreeDSurfaceControl.java:154)
> > at 
> > ucar.unidata.idv.control.DisplayControlImpl.init(DisplayControlImpl.java:1259)
> > at 
> > ucar.unidata.idv.control.DisplayControlImpl.init(DisplayControlImpl.java:966)
> > at 
> > ucar.unidata.idv.ControlDescriptor.initControl(ControlDescriptor.java:979)
> > at ucar.unidata.idv.ControlDescriptor$1.run(ControlDescriptor.java:904)
> > at ucar.unidata.util.Misc$3.run(Misc.java:1038)
> >
> >
> >
> 
> 
> Ticket Details
> ===================
> Ticket ID: IAQ-137060
> Department: Support IDV
> Priority: Normal
> Status: Open
> 
> 


Ticket Details
===================
Ticket ID: IAQ-137060
Department: Support IDV
Priority: Normal
Status: Open