东亚磁异常及其对中国东北地区地磁场的影响

Magnetic anomaly in East Asia and its effect on thegeomagnetic fields at the northeast region in China

利用东亚及邻区４９个地磁台１９７０一１９７９年Ｄ、Ｈ、Ｚ的实测年均值，逐年计算、绘制了蒙古异常的地磁非偶极场等值图，给出了蒙古异常非偶极场Ｚｎ分量的焦点位置和强度变化及其对中国东北地区地磁场的影响量级，计算表明蒙古异常的年变化是该区地磁场年变化的主要成份。

In this paper,the measured annual mean values of D、H、Zin l970一l979 of 49geomagnetic observatories in East Asia and its adjacent areas were calculated consecutively from year to year,the isopleth of the magnetic non-dipole field of the Mongoliananomaly was charted, the focal positions and the intensity changes of Zn component ofnon-dipole fields were produced, and the magnitude of its effect on the magnetic fields inthe northeast region in China as well. The calculation shows that the annual changes ofthe Mongolian anomaly is the main element in the annual variation of the geomagneticfield in that area.