1980．0年东亚地区地磁场的勒让德多项式模型

LEGENDRE POLYNOMIAL MODELS OF THE GEOMAGNETIC FIELD OVER THE EASTERN ASIA AT EPOCH 1980.0

根据中国、原苏联等地区的地磁复测点和地磁台资料，利用勒让德多项式方法，计算出１９８０．０年东亚地区的地磁场模型，绘制出总强度（Ｆ）、磁偏角（Ｄ）和磁倾角（Ｉ）地磁图．地磁场模型的均方偏差分别为：总强度１４４．６ｎＴ，磁偏角１９．１′，磁倾角８．５′．将勒让德多项式模型与ＤＧＲＦ１９８０进行了比较，并绘制出总强度的差值分布图．本文计算出来的地磁场勒让德多项式模型能较好地表示东亚地区地磁场的分布．

Based on the geomagnetic repeat station data and the geomagnetic observatoryannual mean values,including 98 repeat stations in China,and 100 repeat stations in the USSR and 39 geomgnetic observatories in the Eastern Asia, the geomagnetic field models were derived by using the Legendre polynomial method. The rootmean square deviations are 144.6nT for total intensity,19.1′for declination and 8.5′for inclination.The geomagnetic charts over the Eastern Asia at epoch 1980.0were drawn.The comparisons between the Legendre polynomial models and DGRF1980 model were done. The fitting effects of the Legendre polynomial models aresatisfactory. The main results of the present work are following: 1.The methodis presented for the representing the geomagnetic field distribution on the limitedregions based on the expanding the geomagnetic field in the Legendre polynomial.2. The all geomagnetic data in China and the USSR for 1980.0 were gathered andanalysed. 3.It is derived the 7-order Legendre polynomial models of the geomagnetic field over the Eastern Asia at epoch 1980.0.