|
|
- 2018
利用重力和VLBI技术检测地球液态核的动力学效应
|
Abstract:
利用最新的武汉地区高精度重力和全球高精度甚长基线干涉（very long baseline interferometry，VLBI）测量技术观测确定了地球液态地核的自由核章动本征参数（包括本征周期和品质因子等），同时获得了液核顶部的粘滞系数和液核的真实动力学椭率，使用Monte Carlo方法研究了本征周期的不确定度。结果表明，分别利用重力和VLBI确定的地球自由核章动本征周期值为430 sd（sd指恒星日）左右，两者间的差异为1.47 sd，粘滞系数为1 028 Pa·s。讨论了导致两者差异的主要原因，并将结果与国内外同类研究结果作了对比
| [1] | Koot L, Rivoldini A, Viron O D, et al.Estimation of Earth Interior Parameters from a Bayesian Inversion of very Long Baseline Interferometry Nutation Time Series[J]. Journal of Geophysical Research:Solid Earth, 2008, 113:B08414 |
| [2] | Vondrák J, Ron C. New Method for Determining Free Core Nutation Parameters, Considering Geophysical Effects[J]. Astronomy & Astrophysics, 2017, 604(A56):1-7 |
| [3] | Vondrák J, Ron C. Stability of Period and Quality Factor of Free Core Nutation[J]. Acta Geodynamica et Geomaterialia, 2009, 6(3):217-224 |
| [4] | Cui Xiaoming, Sun Heping, Xu Jianqiao, et al. Temporal Variation of the Period of Free Core Nutation Derived from VLBI and Superconducting Gravity Data[J]. Chinese Journal of Geophysics, 2014, 57(2):384-391(崔小明, 孙和平, 徐建桥,等. 利用VLBI和超导重力资料研究自由核章动周期时变特征[J]. 地球物理学报, 2014, 57(2):384-391) |
| [5] | Smylie D E, Palmer A. Viscosity of Earth's Outer Core[OL]. http://arxiv.org/abs/0709.3333, 2007 |
| [6] | Cui Xiaoming, Sun Heping, Xu Jianqiao, et al. Application of Superconductive Gravity Technique on the Constraints of Core-Mantle Coupling Parameters[J]. Sci China:Earth Sci, 2012, 55(3):513-520(崔小明, 孙和平, 徐建桥,等. 利用超导重力技术约束核幔耦合参数[J]. 中国科学:地球科学, 2012,55(3):513-520) |
| [7] | Zhou Y, Zhu Q, Salstein D A, et al.Estimation of the Free Core Nutation Period by the Sliding-Window Complex Least-Squares Fit Method[J]. Advances in Space Research, 2016, 57(10):2136-2140 |
| [8] | Lambert S, Ziegler Y, Huda N, et al.Earth's Nutation:Recent Advances in Improving the Accuracy of Their Measurement by VLBI and in Constraining the Fluid and Inner Core Resonances[C]. EGU General Assembly Conference, Vienna, Italy, 2018 |
| [9] | Jia Jiangang, Luan Wei, Shen Wenbin. Accurate Determination of the Calibration Factor of iGrav-007 Superconducting Gravimeter[J]. Geomatics and Information Science of Wuhan University, 2015, 40(10):1366-1370(贾剑钢, 栾威, 申文斌. iGrav-007超导重力仪格值的精密测定[J]. 武汉大学学报·信息科学版, 2015, 40(10):1366-1370) |
| [10] | Sun Heping, Cui Xiaoming, Xu Jianqiao, et al. Preliminary Application of Superconductive Gravity Technique on the Investigation of Viscosity at Core-Mantle Boundary[J]. Chinese Journal of Geophy-sics, 2009, 52(3):637-645(孙和平, 崔小明, 徐建桥,等. 超导重力技术在探讨核幔边界黏性特征中的初步应用[J]. 地球物理学报, 2009, 52(3):637-645) |
| [11] | Mathews P M, Buffett B A, Herring T A, et al. Forced Nutations of the Earth:Influence of Inner Core Dynamics:2. Numerical Results and Comparisons[J]. Journal of Geophysical Research:Solid Earth, 1991, 96(B5):8243-8257 |
| [12] | Sun H P, Jentzsch G, Xu J Q, et al. Earth's Free Core Nutation Determined Using C032 Superconducting Gravimeter at Station Wuhan/China[J]. Journal of Geodynamics, 2004, 38(3-5):451-460 |
| [13] | Lambert S B, Dehant V. The Earth's Core Parameters as Seen by the VLBI[J]. Astronomy & Astrophysics, 2007, 469(2):777-781 |
| [14] | Xu Houze, Sun Heping.GGP Project and Observations Using Wuhan Superconducting Gravimeter[J]. Geomatics and Information Science of Wuhan University, 2003, 28(S1):18-22(许厚泽, 孙和平. 国际GGP计划和武汉超导重力仪观测[J]. 武汉大学学报·信息科学版, 2003, 28(S1):18-22) |
| [15] | Ducarme B, Sun H P, Xu J Q, et al. Determination of the Free Core Nutation Period from Tidal Gravity Observations of the GGP Superconducting Gravimeter Network[J]. Journal of Geodesy, 2007, 81(3):179-187 |
| [16] | Florsch N, Hinderer J. Bayesian Estimation of the Free Core Nutation Parameters from the Analysis of Precise Tidal Gravity Data[J]. Physics of the Earth & Planetary Interiors, 2000, 117(1-4):21-35 |
| [17] | Herring T A, Gwinn C R, Shapiro I I. Geodesy by Radio Interferometry:Studies of the Forced Nutations of the Earth:1. Data Analysis[J]. Journal of Geophysical Research:Solid Earth, 1986, 91(B5):4745-4754 |
| [18] | Wahr J M. Body Tides on an Elliptical, Rotating, Elastic and Oceanless Earth[J]. Geophysical Journal of the Royal Astronomical Society, 1981, 64(3):677-703 |
| [19] | Rosat S, Florsch N, Hinderer J, et al. Estimation of the Free Core Nutation Parameters from SG Data:Sensitivity Study and Comparative Analysis Using Linearized Least-Squares and Bayesian Methods[J]. Journal of Geodynamics, 2009, 48(3):331-339 |
| [20] | Wenzel H G. The Nanogal Software:Earth Tide Data Processing Pakage Eterna3.30[J]. Bulletin d'Information de Marees Terrestres, 1996, 124:9425-9439 |
| [21] | Xu Jianqiao, Zhou Jiangcun, Chen Xiaodong, et al. Long-Term Observations of Gravity Tides from a Superconducting Gravimeter at Wuhan[J]. Chinese Journal of Geophysics, 2014, 57(10):3091-3102(徐建桥, 周江存, 陈晓东,等. 武汉台重力潮汐长期观测结果[J]. 地球物理学报, 2014, 57(10):3091-3102) |
| [22] | Buffett B A, Christensen U R. Magnetic and Viscous Coupling at the Core-Mantle Boundary:Infe-rences from Observations of the Earth's Nutations[J]. Geophysical Journal International, 2007, 171(1):145-152 |
| [23] | Wahr J, Bergen Z. The Effects of Mantle Anelasticity on Nutations, Earth Tides, and Tidal Variations in Rotation Rate[J]. Geophysical Journal International, 1986, 87(2):633-668 |
| [24] | Vondrak J. Free Core Nutation:Direct Observations and Resonance Effects[J]. Astronomy & Astrophysics, 2005, 444(1):297-304 |
| [25] | Chao B F, Hsieh Y. The Earth's Free Core Nutation:Formulation of Dynamics and Estimation of Eigenperiod from the Very-Long-Baseline Interfe-rometry Data[J]. Earth & Planetary Science Letters, 2015, 432:483-492 |
| [26] | Cui Xiaoming. Investigation of the Earth's Free Core Nutation and Core-Mantle Coupling[D]. Wuhan:University of Chinese Academy of Sciences,2013(崔小明. 地球自由核章动及核幔耦合的研究[D].武汉:中国科学院大学,2013) |
| [27] | Neuberg J, Hinderer J, Zürn W. Stacking Gravity Tide Observations in Central Europe for the Retrieval of the Complex Eigenfrequency of the Nearly Diurnal Free-Wobble[J]. Geophysical Journal International, 1987, 91(3):853-868 |
| [28] | Xu J Q, Sun H P, Luo S C.Study of the Earth's Free Core Nutation by Tidal Gravity Data Recorded with International Superconducting Gravimeters[J]. Sci China Earth Sci, 2002, 45(4):337-347 |
| [29] | Rajner M, Brzeziński A. Free Core Nutation Period Inferred from the Gravity Measurements at Józefoslaw[J]. Studia Geophysica et Geodaetica, 2017, 61(4):639-656 |
| [30] | Tamura Y.A Harmonic Development of the Tide Generating Potential[J]. Bulletin d'Informations de Marees Terrestres, 1987, 99:6817-6855 |
| [31] | Palmer A,Smylie D E. VLBI Observations of Free Core Nutations and Viscosity at the Top of the Core[J]. Physics of the Earth & Planetary Interiors, 2005, 148(2-4):285-301 |
