A semi‐global reference model for electrical conductivity in the mid‐mantle beneath the north Pacific region

Utada, Hisashi; Koyama, Takao; Shimizu, Hisayoshi; Chave, Alan D.

doi:10.1029/2002gl016092

Cited by 100 publications

(137 citation statements)

References 26 publications

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“…1). The existing undersea measurement system, for example in the North Paci c Ocean (Fujii and Utada, 2000;Utada et al, 2003) may be used to detect the tsunami induced voltage variations.…”

Section: Discussionmentioning

confidence: 99%

Can undersea voltage measurements detect tsunamis?

et al. 2010

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The movement of electrically conducting ocean water in the ambient geomagnetic eld induces secondary electric and magnetic elds in the oceans. Ocean water transport is now routinely inferred from undersea cable voltage data. We try to answer the question whether the method could also be useful to detect tsunami. A barotropic shallow water model along with a three-dimensional electromagnetic induction code was used to predict the electric elds induced by the Indian Ocean Tsunami occurred on December 26, 2004. We show that the ocean ow related to the Indian Ocean Tsunami must have induced electric voltages of the order of ±500 mV across the existing submarine cables in the Indian Ocean. The electric elds induced by the Tsunami ow have strength within the range of ±10 mV/km, with enhancements along the main ow region and near the coasts and islands. Thus, making use of the in-service or retired submarine cables to measure the electric potential across oceans, it may be possible to detect water movement related to tsunami.

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“…1). The existing undersea measurement system, for example in the North Paci c Ocean (Fujii and Utada, 2000;Utada et al, 2003) may be used to detect the tsunami induced voltage variations.…”

Section: Discussionmentioning

confidence: 99%

Can undersea voltage measurements detect tsunamis?

et al. 2010

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“…This assumes the one-dimensional conductivity model of Utada et al (2003), and this can be updated when the L2PS models become available . To derive the internal degree 1 sources, the time series of orbit averages is first detrended then convolved with a 30 day Q-response filter in the time domain.…”

Section: Step 8: Separate Internal and External Sourcesmentioning

confidence: 99%

Rapid modelling of the large-scale magnetospheric field from Swarm satellite data

Hamilton

2013

Earth Planet Sp

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As part of the European Space Agency (ESA) Swarm mission, ESA has commissioned an independent scientific consortium known as the Swarm satellite Constellation Application and Research Facility (SCARF) to develop and operate the Level 2 Processor (L2PS). Its purpose is to derive high quality scientific products from the mission's data. One such product is the Fast-Track Magnetospheric Model (FTMM), which is a model of the large scale vector magnetospheric field and its induced counterpart. This model is generated once per satellite orbit, in near real-time by a robust, autonomous algorithm. Its intended use is similar to that of the Disturbance storm time Index (Dst): characterising the rapidly varying magnetospheric field, as an input to other global field models, and for the space weather community. In this paper we describe in detail the FTMM algorithm and assess its ability to recover the magnetospheric component from the consortium's test satellite data set as well as real data from the CHAMP satellite.

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“…1 shows the values obtained from the mantle conductivity model of Schmucker (1985b), which is representative for continental areas. The dashed lines are the response of "model B" of Utada et al (2003); this model is representative for oceanic regions. The frequency independent value of Q 1 = 0.27 is shown by a dash-dotted line.…”

Section: Large-scale Magnetospheric Variations and Their Induced Counmentioning

confidence: 99%

“…2 shows two months of D st (black curve) and its constituents E st (red) and I st (blue), separated using the conductivity model of Utada et al (2003). (It is expected that use of a different, but realistic, conductivity model only results in small changes.)…”

Section: Decomposition Of the D St -Index Into External And Induced Partmentioning

confidence: 99%

New parameterization of external and induced fields in geomagnetic field modeling, and a candidate model for IGRF 2005

Olsen¹,

Sabaka

Lowes

2005

Earth Planet Sp

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When deriving spherical harmonic models of the Earth's magnetic field, low-degree external field contributions are traditionally considered by assuming that their expansion coefficient q 0 1 varies linearly with the D st -index, while induced contributions are considered assuming a constant ratio Q 1 of induced to external coefficients. A value of Q 1 = 0.27 was found from Magsat data and has been used by several authors when deriving recent field models from Ørsted and CHAMP data. We describe a new approach that considers external and induced field based on a separation of D st = E st + I st into external (E st ) and induced (I st ) parts using a 1D model of mantle conductivity. The temporal behavior of q 0 1 and of the corresponding induced coefficient are parameterized by E st and I st , respectively. In addition, we account for baseline-instabilities of D st by estimating a value of q 0 1 for each of the 67 months of Ørsted and CHAMP data that have been used. We discuss the advantage of this new parameterization of external and induced field for geomagnetic field modeling, and describe the derivation of candidate models for IGRF 2005.

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A semi‐global reference model for electrical conductivity in the mid‐mantle beneath the north Pacific region

Cited by 100 publications

References 26 publications

Can undersea voltage measurements detect tsunamis?

Can undersea voltage measurements detect tsunamis?

Rapid modelling of the large-scale magnetospheric field from Swarm satellite data

New parameterization of external and induced fields in geomagnetic field modeling, and a candidate model for IGRF 2005

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