How to interpolate model ouput to presure levels?

[rongur@sohu_com]

Hi all
I'm a novice of CAM and have just fininshed some test runs.
But I'm not very clear if there are any fortran codes or scripts to interpolate
the model output to presure levels? Could somebody show me any examples?
Thanks in advance!

 

[rneale]

Did you output any history/diagnostic files? Most variables in the history files are output on (approximately) time-averaged pressure levels (the 'lev' or 'ilev'variable) so you shouldn't need to interpolate.

 

[rongur@sohu_com]

Hi, rneale
Thanks for you reply.
I'v got history files. Since the "lev" or "ilev" are defined as 1000*(A+B),
howerver, I'm not very clear about what you said: history files are output on (approximately) time-averaged pressure levels.

 

[rneale]

The real pressure levels that the model uses are defined as
p(k) = hyam(k)*P0+hybm(k)*Psurface - For model mid levels
p(ik) = hyai(ik)*P0+hybi(ik)*Psurface - For model interface levels

But in the history files this is approximated to

'lev' p(k) = P0*(hyam(k)+hybm(k))
'ilev' p(ik) = P0*(hyim(ik)+hybm(ik))

Which is extremely close to the true definition of p() since the time average of Ps is pretty close to P0=1000mb over most of the globe. If you really want the exact pressure then you can calculate it from PSurf, an the appropriate hybrid cooordinate variables.

 

[rongur@sohu_com]

Hi, rneale
Thank your very much!