We present a simple model for the axial dipole moment (ADM) of the geomagnetic field based on a stochastic differential equation for two coupled particles in a biquadratic potential, subjected to Gaussian random perturbations. This model generates aperiodic reversals and excursions separated by stable polarity periods. The model reproduces the temporal asymmetry of geomagnetic reversals, with slower decaying rates before the reversal and faster growing rates after it. This temporal asymmetry is possible because our model is out of equilibrium. The existence of a thermal imbalance between the two particles sets a preferential sense for the energy flux and renders the process irreversible.

我们提出了一个简单的地磁场轴向偶极矩 (ADM) 模型，该模型基于双二次势中两个耦合粒子的随机微分方程，受到高斯随机扰动。该模型生成由稳定极性周期分隔的非周期性反转和偏移。该模型再现了地磁反转的时间不对称性，反转前衰减速度较慢，反转后增长速度较快。这种时间不对称是可能的，因为我们的模型不平衡。两个粒子之间热不平衡的存在为能量通量设置了优先意义并使该过程不可逆。