Secular variations of the planetary-scale geomagnetic anomalies
文献类型：期刊论文
| 作者 | Xu, WY |
| 刊名 | CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION
 |
| 出版日期 | 2001-03-01 |
| 卷号 | 44期号:2页码:180-189 |
| 关键词 | main geomagnetic field geomagnetic anomaly secular variation westward drift core-mantle boundary(CMB) |
| ISSN号 | 0001-5733 |
| 英文摘要 | The characteristics of a planetary-scale geomagnetic anomaly are described by using' unsigned magnetic flux' through the whole anomaly region. The eighth generation of the International Geomagnetic Reference Filed (IGRF) is analyzed to study the secular variations of 5 planetary-scale geomagnetic anomalies during 1900-2000 period. The results show that the magnetic fluxes through the southern Atlantic anomaly (SAT),Australian anomaly (AUS),and African anomaly(AF) have increased by more than 200MWb, the increase of the flux through the Eurasian anomaly (EA) is smaller(157MWb), while the flux through the North American anomaly (NAM) has decreased by SOMWb. On the other hand, the variations of the anomaly areas are within 10 %. The westward drift at the core-mantle boundary (CMB) is less than 0.1 degrees /a, much slower than that at the Earth surface(0.2 degrees /a). This difference may be attributed to the different westward drift velocities of the harmonics in the geomagnetic field:the westward drift at the Earth surface is controlled by the dominant low-degree harmonics,while the westward drift at the CMB largely depends on high-degree harmonics. Consequently, it should be careful to take the westward drift velocity at the Earth surface as the typical velocity of the fluid flow in the outer core. |
| 语种 | 英语 |
| WOS记录号 | WOS:000167723000005 |
| 出版者 | SCIENCE PRESS |
| 源URL | [http://ir.iggcas.ac.cn/handle/132A11/76587]  |
| 专题 | 中国科学院地质与地球物理研究所 |
| 通讯作者 | Xu, WY |
| 作者单位 | Chinese Acad Sci, Inst Geol & Geophys, Beijing 100101, Peoples R China |
| 推荐引用方式 GB/T 7714 | Xu, WY. Secular variations of the planetary-scale geomagnetic anomalies[J]. CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,2001,44(2):180-189. |
| APA | Xu, WY.(2001).Secular variations of the planetary-scale geomagnetic anomalies.CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION,44(2),180-189. |
| MLA | Xu, WY."Secular variations of the planetary-scale geomagnetic anomalies".CHINESE JOURNAL OF GEOPHYSICS-CHINESE EDITION 44.2(2001):180-189. |
入库方式： OAI收割
来源：地质与地球物理研究所
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