Thank you for your kind reply. I appreciate that. It is great to hear that there is a work-around for this problem, which I will certainly try. Having said that, we still need to find out if there is a bug in AMET code. I had not tried with AMET 1.3 version before when I was writing my question, but then I tried yesterday with the previous version and sure enough version 1.3 also gives the same error. Since I don’t have problem with WRF limited area model comparisons with observations and I can plot 3 km resolution MPAS limited area model results without any problem, I am guessing there is a small error in AMET code in finding the location of observation point over the limited area MPAS domain. SInce I cannot find the “mpas_site_map” function, I got stuck. Just to clarify, I change “only” the path of model output from global MPAS model outputs to the path for the limited area domain MPAS model output (nothing else changes in AMET script) and then the error comes up.
Again, thank you very much for your kind input.