Whole Mantle Electrical Conductivity & the Velocity Field ofUpper Core-Constraints from Applied Mantle Filter Theory, GDS, and improvements in the Global Geomagnetic Database

正在进行的深部地幔电导率研究的初步结果表明，在地幔中部深度存在局部电导率跳跃，电导率梯度的峰值大致与670公里地震不连续相一致。PI将获得整个地幔电导率的更高分辨率模型。这涉及到从磁场傅立叶系数的比值计算等效标量大地电磁阻抗函数。通过对磁场源结构的了解，可以把谱比转化为阻抗。他将把鲁棒统计参数估计的概念应用于球谐分析问题。

Initial results of deep mantle electrical conductivity studies underway suggest that a localized jump in electrical conductivity is present at midmantle depths, with a peak in the conductivity gradient roughly coincident with the 670 km seismic discontinuity. The PI will obtain higher resolution models of the electrical conductivity of the whole mantle. This involves calculating equivalent scalar magnetotelluric impedance functions from ratios of magnetic field Fourier coefficients. The transformation of spectral ratios into impedances is made possible by knowledge of the magnetic field source structure. He will apply concepts of robust statistical parameter estimation to the problem of spherical harmonic analysis.