What is lfric_atm-checksums.txt?

[Björn Fock (BHFock)]

While running the canned configuration from the lfric_atm/example, I noticed that the model LFRic Atmosphere writes the file lfric_atm-checksums.txt:

Inner product checksum rho = 405F163A37CF0717
Inner product checksum theta = 41B09B090C8AE887
Inner product checksum u = 44035B926C8572D4
Inner product checksum mr1 = 3F901037544354E5
Inner product checksum mr2 = 3E3CF684EB2B8268
Inner product checksum mr3 = 3DBDE2F11F7F42BD
Inner product checksum mr4 = 0
Inner product checksum mr5 = 0
Inner product checksum mr6 = 0

What is the meaning of these checksums and for what are they used?

[Andrew Coughtrie (andrewcoughtrie)]

They are the inner product of the fields stated and are used for KGO checking. The algorithm that calculates them is here: sci_checksum_alg_mod.x90

[Björn Fock (BHFock)]

Is that for the state of the fields after the last time step?

[Andrew Coughtrie (andrewcoughtrie)]

It is usually done in the finalise of the application so yes.