[ncl-talk] Era-interim vertical levels

[mireiyue]

Dear NCL users

I am trying to calculate monthly mean of updraught from  Era-interim. It has 60 vertical levels and I need to change it to standard pressure levels. So, trying to find a and b coefficient files but I couldn’t find any. I wonder if there are some examples from NCL. Is there anything (scripts or tips) that I can refer?
I appreciate any suggestion and advice. 

Thank you for helping.
Sun