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[IDV #OVR-601731]: IDV Problems Using CF Compliant WRF Files



> Hi Yuan,
> 
> Finally the IDV vertical scaling worked! I copied the 4 original WRF 
> perturbed variables P, PB, PH, and PBH and vertical units on the cross 
> section plot display as expected.
> 
> I do have a post-mortem comment, however. It would be great if IDV had more 
> helpful error messages instead of just telling users non-helpful generic 
> things like "unknown vertical coordinate". It indeed would have saved you and 
> me a huge amount of unnecessary troubleshooting time. As a "role model" 
> example, in NCL I tried to produce a PV variable, but NCL told me I did not 
> have MAPFAC_U variables in my file. So I obtained them, appended them to the 
> file, and then PV was produced by NCL without error.
> 
> I do have a couple more questions:
> 
> 1) In "Plan View" displays, levels (my 51 levels, e.g.) are specified in eta 
> values ranging from 0.997 to 0.421. Is there any way in IDV to display plan 
> view levels in more relevant units, such as height in meters or pressure in 
> hPa? If so, can you tell me how or share an example of how this can be done?

It is possible, but not currently available in the IDV. The dataset is in the 
sigma coordinate, we need to write a formula to extract the data value at each 
meter or pressure level. The easy way is to convert the whole dataset to the 
pressure coordinate in the WRF post precess script.
> 
> 2) I am producing some variables (e.g., theta) that are interpolated to 
> pressure levels using NCL. Can IDV display vertical cross sections vertically 
> scaled by pressure level? If so, can you tell me how or share an example of 
> how this can be done?

Yes, you can use the transect display to see the pressure levels cross section. 
 Here is the tutorial link:

https://www.unidata.ucar.edu/software/idv/docs/workshop/page_transectviews.html

You can see in this type of display, you don't need to convert to pressure 
coordinate, you can directly do it in the sigma coordinate.

Yuan
> 
> Thanks!
> 
> Jim
> 
 

Ticket Details
===================
Ticket ID: OVR-601731
Department: Support IDV
Priority: High
Status: Closed
===================
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