This is the first time I'm asking a question in ferret_users group, so please let me know if I could convey my question properly to all.
eddy_amplitude, longitude, and latitude.
Each of these variables have only 1 axis, i.e. J axis.
For example,
currently SET data sets:
1> ./20140101.nc (default)
name title I J K L
AMPLITUDE ... 1:3 ... ... LONGITUDE ... 1:3 ... ...
LATITUDE ... 1:3 ... ...