Hybrid to pressure interpolation

[djaber]

Hi,
I have a question about vertical levels interpolation:
When I make interpolation of CESM2 model hybrid levels to pressure levels, for some variables (ua, va and hus), using the "vinth2p(datai, hbcofa, hbcofb, plevo, data_PS, intyp, p0, ii, kxtrp)" formula, the interpolation is not done for the first pressure levels (1000hpa to 850hpa)? I get only fields aboave the 850hpa
In steed, when I had used the CESM1 model this runs well over all the pressure levels.
Do you have an explanation or solutions? Thanks a lot.

 

[nusbaume]

Hi djaber,

The vertical coordinate system as output to the history files should essentially be the same between CESM1 and CESM2 (both are a sigma/pressure hybrid coordinate system). I just tried NCL's "vinth2p" function myself on the variable "U" contained within a CESM2 "h0" file, and it produced the lower pressure levels as expected. So the routine should work for the default CESM2 outputs.

Thus my only guess is that somehow your "vinth2p" function is not being called correctly. For example, does your "plevo" inputs contain all of the pressure levels you are interested in, and are you reading in the correct interpolation variables from CAM (hyam, hybm, P0, and PS)?

If you are still having trouble, and are using NCL, then I would recommend sending an email to ncl-talk@ucar.edu to see if someone there can provide assistance. You can find more info about that mailing list here.

Hope that helps, and have a great day!

Jesse