Using ‘‘domino’’ model to study the secular variation of the geomagnetic dipolar moment

Aiming to understand the physical processes underneath the reversals events of geomagnetic field, different
numerical models have been conceived. We considered here the so named ‘‘domino’’ model, an
Ising–Heisenberg model of interacting magnetic macrospins aligned along a ring. This model was proposed
by Mazaud and Laj (1989) and then applied by Mori et al. (2013) to study geomagnetic field reversals.
The long series of the axial magnetic moment (dipolar moment or ‘‘magnetization’’) generated by the
‘‘domino’’ model are empirically studied by varying all model parameters. We present here some results
which are slightly different from those given by Mori et al. (2013), and will provide our explanation on
the presence of these differences. We also define the set of parameters that supply the longest mean time
between reversals. Using this set of parameters, a large number of time series of axial magnetic moment
are also generated. After de-noising the fluctuation of these time series and averaging them, we compared
the resulting averaged series with the series of axial dipolar magnetic moment values supplied
by CALS7k.2, and CALS10k.1b models, finding similar behavior for the all time series. In a similar way,
we also compared the averaged 14,000 years long series of dipolar moment with the dipolar magnetic
moment obtained by the model SHA.DIF.14k.