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Which fields to use in CAM-SE high res output for Z500 and Z200

mberdahl

Mira
New Member
I have a super simple question about what field to use in CAM-SE high res output. In my lower res runs, CAM has output fields such as Z500 and Z200 (geopotential heights at 200 and 500mb). However, the high resolution run data does not seem to have the same fields available. Would lit be most appropriate to use the Z3 output and then just extract the closets levels to match these pressure levels? Or is there a better way here? Thanks!
 

strandwg

Moderator
Staff member
I have a super simple question about what field to use in CAM-SE high res output. In my lower res runs, CAM has output fields such as Z500 and Z200 (geopotential heights at 200 and 500mb). However, the high resolution run data does not seem to have the same fields available. Would lit be most appropriate to use the Z3 output and then just extract the closets levels to match these pressure levels? Or is there a better way here? Thanks!

It should be possible to output those fields at higher resolution; if not, then you need to interpolate Z3 to pressure levels. You can't just pick the closest, as the CAM vertical coordinate isn't on pressure levels.

The NCL function "vinth2p" does this interpolation.
 

mberdahl

Mira
New Member
It should be possible to output those fields at higher resolution; if not, then you need to interpolate Z3 to pressure levels. You can't just pick the closest, as the CAM vertical coordinate isn't on pressure levels.

The NCL function "vinth2p" does this interpolation.
Excellent, thanks I'll give that a shot.
 

mberdahl

Mira
New Member
I've now used the python function interp_hybrid_to_pressure to extract the Z500 and Z200 geopotential heights from CAM's Z3 field. I have a few questions regarding whether my output actually makes sense. Attached is a screenshot of the output which shows that the geopotential height at 500mb contains topographic influence, which I believe ought not be there. I've double checked all my pressure field inputs are in Pa. Am I just interpreting this wrong? Or is there something off about this output?

Screenshot-2024-02-15-at-2.40.16-PM.png

 

mberdahl

Mira
New Member
I've now used the python function interp_hybrid_to_pressure to extract the Z500 and Z200 geopotential heights from CAM's Z3 field. I have a few questions regarding whether my output actually makes sense. Attached is a screenshot of the output which shows that the geopotential height at 500mb contains topographic influence, which I believe ought not be there. I've double checked all my pressure field inputs are in Pa. Am I just interpreting this wrong? Or is there something off about this output?

Screenshot-2024-02-15-at-2.40.16-PM.png

Nevermind! I was accidentally calling PSL instead of PS in the function. All makes sense again.
 
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