OpenIFS model known issues

Limitation in run length from GSTATS due to counter overflow from total number of timesteps

In cases of very long integrations the OpenIFS model can fail because of the overflow in some integer counters due to the total number of timesteps.

The GSTATS statistics for transforms can only be called NCALLS(KNUM) times. This variable is defined as:

INTEGER(KIND=JPIM) :: NCALLS(0:JPMAXSTAT)

which means that it is limited to 2³¹-1 = 2147483647 calls of transformations or any other package for which the GSTATS statistics are used.  Adding one to this maximum number turns this counter to be -2147483647 which then causes the model to crash.

The error is something like:

KNUM,KSWITCH,IMOD,NCALLS(KNUM) 805,  0,  -1,  -2147483647 ABORT!  408 GSTATS
 MPL_ABORT: CALLED FROM PROCESSOR    408 THRD     

The solution in this case is to switch off the GSTATS statistics, or (preferably) shorten the length of integration between restarts.

Contact openifs-support@ecmwf.int for assistance or further information.