[ferret_users] BUG REPORT: TSERIES creates spurious modulo axes

[Russ Fiedler <russell.fiedler@xxxxxxxx>]

Hi,


I'm aggregating some files from MOM output data with TSERIES but Ferret 
insists on making the time axis "modulo" for some reason.

Issuing "CAN AXIS/MOD time"  fixes things but it's a pain.

Each file has 12 months of data

From an ncdump on a file

...

    time = UNLIMITED ; // (12 currently)
...

    double time(time) ;
        time:long_name = "time" ;
        time:units = "days since 0001-01-01 00:00:00" ;
        time:cartesian_axis = "T" ;
        time:calendar_type = "NOLEAP" ;
        time:calendar = "NOLEAP" ;
        time:bounds = "time_bounds" ;


There's no modulo attribute here.

But SHOW AXIS

 time      TIME                24mi   16-JAN 12:00 16-DEC-0002 
12:00         <---- start time has no year!

It looks to be a problem when the base year is 0001.

When I changed the base year in the units string to 0010 it looks fine

 time      TIME                24 i   16-JAN-0010 12:00 16-DEC-0011 12:00


On further investigation it looks like a general problem with having a 
file with data only in the year 0001. Ferret seems to get a bit too 
frisky and wants to make climatologies no matter what.


If I load only the first year a climatology is automatically made

 time      TIME                12mi   16-JAN 12:00         16-DEC 12:00

if I load the second year by itself it's fine

 time      TIME                12 i   16-JAN-0002 12:00 16-DEC-0002 12:00


If I concatenate the two files using ncrcat no climatology is made.

 time      TIME                24 i   16-JAN-0001 12:00 16-DEC-0002 12:00

Cheers,

Russ