secular variation

基本解释

By statistical classification, tabulation and drawing, the distribution regularity and characters of the secular variation are gotten.
哪些属于逐年下降，统计分类、列表、绘图，最后得出了南极洲地磁长期变化分布规律及变化特征。
After an analysis of the secular variation of the common Z-Term in latitude, the existence of the non-polar long period terms in latitude is verified.
本文从讨论纬度公共Z项长期变化的规律入手，证实了纬度非极变化中存在着某些长周期项。
According to observation data at geomagnetic stations in Hebei Province from 1986 to 2005, we sum up and analyze the laws of the geomagnetic secular variation in this paper.
利用河北省地磁台1986～2005年的地磁观测资料，对该地区地磁场长期变化规律进行总结分析。