[MITgcm-support] mnc questions

[Michael Schaferkotter (Contractor)]

mnc is working as advertised.

has anyone any offerings with respect runtime performance with and without mnc?
does anyone know what the 'performance hit' is for using mnc?

secondly, in some fields like U,V,W a zero value is quite expected. when using ncview the meaningful U,V,W zero values
become obscured by the fact that the field gets assigned 0 at land points. it would be better to put a   
'missing value' of say -1.0e34 where there is land for ncview, otherwise nco can perform statistical operations on these fields
that are meaningless. for example a large domain with few ocean points in which the velocity is everywhere 1.
if there is any land in the domain, then the avg velocity will not be 1.

the nc operators are smart enough to ignore missing values. you/ll need to add that attribute to the .nc files.
if you then read the .nc files in for the model, you might have to filter the missing values and assign them a more
benign value (say zero).

m. r. schaferkotter