[IDV #WGK-260322]: WRF cross-sections: showing terrain and freezing level

> Hi Yuan,
> Great, I think that general approach will work, but I was wondering if
> there is an easy way/function to plot temperature in C using the wrfout
> fields of perturbation potential temperature, etc.
> If not, I can try to just write a function to do it, but I figured that
> since it is probably a pretty common thing WRF users want to do that it
> might already be done in IDV somehow.
> Thanks again so much for your help!
> Kelly
> 
> 

Kelly,
    There is a system function to convert the temperature to potential 
temperature, but not the other way. I will be happy to work with you to add 
this function if you think this is a commonly use function in the community.


Yuan  
> 
> On 5/20/2011 1:33 PM, Unidata IDV Support wrote:
> >> Hi Yuan,
> >> Great, thank you so much -- I knew I had seen a way to do that before
> >> but had completely forgotten about the data transect display.
> >> I have followed your instructions and now have my hydrometeor field
> >> plotted with terrain.
> >>
> >> One last addition that I need to make but am stuck on -- and this may be
> >> a more general question about how to go from WRF output fields (like
> >> perturbation pot temp) to temperature.
> >> I would like to plot the 0-deg-isotherm on the cross-section, i.e., the
> >> freezing level height.
> > I would suggest to do the contour cross section  in the transect view 
> > first, and then in the Dashboard window, under Displays control, you can 
> > easily modify the contour, to only display certain value contour by setting 
> > the base contour to this value, and the contour interval to 0 or very big 
> > number. Give it a try and let me know if it doesn't work.
> >
> >
> >
> > Yuan
> >> Can you offer any insight on how that would be most effective way to do
> >> that given the fields that are given in the wrfout netcdf files?
> >>
> >> Thanks again very much for your help -- I really appreciate it!
> >> Best,
> >> Kelly
> >>
> >>
> >>
> >>
> >>
> >> On 5/20/2011 9:43 AM, Unidata IDV Support wrote:
> >>>> Full Name: Kelly Mahoney
> >>>> Email Address: address@hidden
> >>>> Organization: UCAR/NOAA
> >>>> Package Version: 2.9u1 build date:2010-09-02 19:36 UTC
> >>>> Operating System: Windows XP
> >>>> Hardware: Java: home: C:\Program Files\IDV_2.9u1\jre version: 1.6.0_20 
> >>>> j3d:1.5.2 fcs (build4)
> >>>> Description of problem: Hi,
> >>>> I'm trying to do vertical cross-section plots of various hydrometeor 
> >>>> fields with the WRF model terrain shown, as well as the freezing level 
> >>>> height. I can do the hydrometeor displays no problem but can't figure 
> >>>> out how to see the terrain via the cross-section tool. The terrain 
> >>>> height fields are 2D, but you can plot them as topography in 3D...so I'm 
> >>>> wondering if there's a way to get that into a 2D vertical cross section 
> >>>> as well?
> >>> Hi Kelly,
> >>>          The answer to your question is yes, the IDV can plot a 2D 
> >>> vertical cross section of 2D terrain height. When you want to put 
> >>> multiple field in the same cross section, you need to bring up the 
> >>> transect view window, File>   New>   View Window>   Misc>   Transect and 
> >>> Map, and it will
> >>> be good to close the original map view window to avoid the confusion. To 
> >>> display the 2D cross section of terrain, select the Transect View on the 
> >>> left by clicking in the window, and select the terrain data source in the 
> >>> Field Selector and create a Data Transect display.  In the transect 
> >>> display, you can add multiple fields. To reproduce the C image, you first 
> >>> create a cross section display of certain variable, and then create the 
> >>> Data Transect display of terrain. Here is a detail information of 
> >>> workshop guide of the transect display:
> >>>
> >>> "http://www.unidata.ucar.edu/software/idv/docs/workshop/datadisplays/transect/TransectDisplay.html";
> >>>
> >>> Yuan
> >>>
> >>>
> >>>> I'm attaching a pdf file with 3 images:
> >>>> a. just the hydromet field -- I'd like to add an outline of the model 
> >>>> terrain through this particular cross-section to it (as well as freezing 
> >>>> level height eventually)
> >>>> b. *almost* what I'm getting at, but doing it this way shows all of the 
> >>>> terrain and not just through that vertical plane...and the background of 
> >>>> the vert cross-section blocks the terrain anyway.
> >>>> c. A similar plot I made in NCL, just as an example of what I am going 
> >>>> for  -- it has its own issues, which is why I'd prefer to do this in IDV.
> >>>> (Adding the freezing level is another question, and more fundamental 
> >>>> perhaps, about how to turn standard WRF output variables (i.e., 
> >>>> perturbation pot temp, etc) into actual temperature to plot the 0deg 
> >>>> isotherm...)
> >>>> Thanks very much in advance for any help or suggestions you may have!
> >>>> Kelly Mahoney
> >>>>
> >>>>
> >>>>
> >>> Ticket Details
> >>> ===================
> >>> Ticket ID: WGK-260322
> >>> Department: Support IDV
> >>> Priority: Normal
> >>> Status: Open
> >>>
> >>
> >
> > Ticket Details
> > ===================
> > Ticket ID: WGK-260322
> > Department: Support IDV
> > Priority: Normal
> > Status: Open
> >
> 
> 


Ticket Details
===================
Ticket ID: WGK-260322
Department: Support IDV
Priority: Normal
Status: Open