1950—1985年中国地磁长期变化的模型和分析

对1950年以来中国及其邻近地区的地磁观测台和复测点地磁三分量数据进行了系统地分析,求得这期间每5年的共7组地磁长期变化的模型（SV模型）.利用这些SV模型将需要的地磁观测值归算到所需的年代,很好地建立了1950—1985年中国地区的主磁场模型.文中还表示了中国地区1950年以来地磁各分量地磁长期变化的时空变化趋势.这些SV模型系数和国际参考地磁场系数计算的SV值与相应观测的SV值比较,由中国SV模型系数得到的均方值比国际参考场的小.

AN ANALYSIS AND THE MODELS OF THE GEOMAGNETIC SECULAR VARIATION IN CHINA FOR 1950-1985

The geomagnetic data available from the geomagnetic observatories and repeat stations in China and its adjacent areas for 1950-1986 year have been collected. The geomagnetic secular variation models （SV） have been established for 1950-1955, 1955-1960, 1960-1965, 1965 -1970, 1970-1975, 1975-1980 and 1980-1985 intervals respectively, and the distribution of geomagnetic secular variation were analysed in above regions.These SV models have. been used to established the main field models for 1950, 1960, 1970 and 1980. the fitting results of these main field models are satisfactory. R.M.S values of these SV models compared with observed SV values for various components are smaller than that of IGRF.