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DOI | 10.1029/2019GL082915 |
Geodynamo Conductivity Limits | |
Driscoll, Peter E.1; Du, Zhixue2,3 | |
2019-07-28 | |
发表期刊 | GEOPHYSICAL RESEARCH LETTERS
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ISSN | 0094-8276 |
EISSN | 1944-8007 |
出版年 | 2019 |
卷号 | 46期号:14页码:7982-7989 |
文章类型 | Article |
语种 | 英语 |
国家 | USA; Peoples R China |
英文摘要 | In a metal, as in Earth's core, the thermal and electrical conductivities are assumed to be correlated. In a planetary dynamo this implies a contradiction: that both electrical conductivity, which makes it easier to induce current and magnetic field, and conductive heat transport, which hinders thermal convection, should increase simultaneously. Here we show that this contradiction implies that the magnetic induction rate peaks at a particular value of electrical and thermal conductivity and derive the low- and high-conductivity limits for thermal dynamo action. A dynamo regime diagram is derived as a function of electrical conductivity and temperature for Earth's core that identifies four distinct dynamo regimes: no dynamo, thermal dynamo, compositional dynamo, and thermocompositional dynamo. Estimates for the temperature-dependent electrical conductivity of the core imply that the geodynamo may have come close to its high-conductivity "no dynamo" limit prior to inner core nucleation, consistent with recent paleomagnetic observations. |
英文关键词 | geodynamo Earth' s core electrical conductivity |
领域 | 气候变化 |
收录类别 | SCI-E |
WOS记录号 | WOS:000481818900014 |
WOS关键词 | ELECTRICAL-RESISTIVITY ; THERMAL-CONDUCTIVITY ; EARTHS CORE ; CONVECTION ; DRIVEN ; IRON ; EVOLUTION ; CONSTRAINTS ; ALLOYS ; HEAT |
WOS类目 | Geosciences, Multidisciplinary |
WOS研究方向 | Geology |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://119.78.100.173/C666/handle/2XK7JSWQ/185277 |
专题 | 气候变化 |
作者单位 | 1.Carnegie Inst Sci, Dept Terr Magnetism, 5241 Broad Branch Rd NW, Washington, DC 20015 USA; 2.Carnegie Inst Sci, Geophys Lab, Washington, DC 20015 USA; 3.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Isotope Geochem, Guangzhou, Guangdong, Peoples R China |
推荐引用方式 GB/T 7714 | Driscoll, Peter E.,Du, Zhixue. Geodynamo Conductivity Limits[J]. GEOPHYSICAL RESEARCH LETTERS,2019,46(14):7982-7989. |
APA | Driscoll, Peter E.,&Du, Zhixue.(2019).Geodynamo Conductivity Limits.GEOPHYSICAL RESEARCH LETTERS,46(14),7982-7989. |
MLA | Driscoll, Peter E.,et al."Geodynamo Conductivity Limits".GEOPHYSICAL RESEARCH LETTERS 46.14(2019):7982-7989. |
条目包含的文件 | 条目无相关文件。 |
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