地磁场长期变化特征及机理分析_郭凤霞.pdfVIP

50 6 Vol. 50, No. 6 2007 11 CHINESE JOURNAL OF GEOPHYSICS Nov. , 2007 , , . . , 2007, 50( 6) : 1649~ 1657 Guo F X, Zhang Y J, Yan M H. The se ular variation hara teristi s and me hanisms of geomagneti field. Chinese J . Geop hys . ( in Chinese) , 2007, 50( 6) : 1649~ 1657 1 2 1 郭凤霞 , 张义军, 言穆弘 1 , 730000 2 , 100081 : , ( CMB) . ( IGRF) 1900~ 2000 , . , , . , , , , 0001- 5733( 2007) 06- 1649- 09 P318 2007- 01- 12,2007- 05- 23 The secular variation characteristics and mechanisms of geomagnetic field 1 2 1 GUO Feng-Xia , ZHANG Y-i Jun , YAN Mu-Hong 1 Cold and Arid Regions Environmental and Engineeri ng Research Institute , ChineseA cademy of Sciences , Lanz hou 730000, China 2 ChineseA cademy of Meteorological Sciences , Bei ing 100081, Chi na Abstract The variations of geomagneti field are divided into three parts, the spontaneous variations of dipole and non-dipole geomagneti fields, and the dipole geomagneti field variation resulting from geomagneti anomaly areas of non-dipole field through modulating the ring urrent in CMB. The se ular variation hara teristi s and distributions of geomagneti field at different depths are al ulated and analysed in this paper by using the model of International Geomagneti Referen e Field ( 1900 ~ 2000) . Possible me hanisms are dis ussed. It an be on luded that the westward drift and reverse of geomagneti field are not only resulted from non-dipole field, but also dipole. Keywords Geomagneti f