应用NOC方法研究中国地区地磁时空变化

Research of geomagnetic spatial-temporal variations in China by the NOC method

应用自然正交分量(NOC)方法,对1995-2006年中国地区36个地磁台的地磁场观测数据进行了计算,获得了上述数据矩阵的本征值和相应的空间域、时间域本征向量,并就其时空分布与中国地磁模型(CGM)进行了对比分析,探讨了它的物理意义.研究表明,上述观测数据包含了丰富的地磁内、外源场信息,其中地磁场要素F、D、I第一、第二本征值及相应的空间域和时间域的第一、第二本征向量所描述的地磁基本场时间变化与CGM吻合较好.

The geomagnetic data at 36 observatories in China during 1995-2006 were calculated by using the natural orthogonal component （NOC） method. We have obtained the eigenvalues and their corresponding eigenvectors in the space and time domains for the above-mentioned data matrix. A comparative analysis between its spatial-temporal distribution and the China Geomagnetic Model （CGM） is made, and its physical meaning is studied. The research shows that the these observational data contain rich information of the internal and external geomagnetic source fields. The first and the second eigenvalues of the geomagnetic field components F, D and I, and the temporal variations of the geomagnetic main field described by the first and the second eigenvalues of the corresponding spatial-temporal domains coincide fairly well with the CGM.