True iff this rank folds through the exchange (px > 1 and a
folded north edge on this rank). False on every px = 1 run and
on ranks off the north row.
pure function ocean_fold_is_distributed() result(flag) !! True iff this rank folds through the exchange (`px > 1` and a !! folded north edge on this rank). False on every `px = 1` run and !! on ranks off the north row. logical :: flag flag = fx_initialised .and. fx_active end function ocean_fold_is_distributed