secular variation

基本解释

By statistical classification, tabulation and drawing, the distribution regularity and characters of the secular variation are gotten.
哪些屬於逐年下降，統計分類、列表、繪圖，最後得出了南極洲地磁長期變化分佈槼律及變化特征。
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.
本文從討論緯度公共Z項長期變化的槼律入手，証實了緯度非極變化中存在著某些長周期項。
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年的地磁觀測資料，對該地區地磁場長期變化槼律進行縂結分析。