satellite; mantle; geomagnetic field; adjoint approach; response functions; three-dimensional models ; electromagnetic induction; integral equations; optimization methods; inversion; electrical conductivity
Püthe Christoph, Kuvshinov Alexey, Olsen Nils (2014), Handling complex source structures in global EM induction studies: From c-responses to new arrays of transfer functions, in Geophysical Journal International
, 201(1), 318-328.
Püthe Christoph, Manoj Chandrasekharan, Kuvshinov Alexey (2014), Reproducing electric field observations during magnetic storms by means of rigorous 3-D modelling and distortion matrix co-estimation, in Earth, Planets and Space
, 66(1), 1.
Püthe Christoph, Kuvshinov Alexey (2013), Determination of the 1-D distribution of electrical conductivity in Earth's mantle from Swarm satellite data, in Earth, Planets and Space
, 65(11), 1233-1237.
Püthe Christoph, Kuvshinov Alexey (2013), Determination of the 3-D distribution of electrical conductivity in Earth's mantle from Swarm satellite data: Frequency domain approach based on inversion of induced coefficients, in Earth, Planets and Space
, 65(11), 1247-1256.
Püthe Christoph, Kuvshinov Alexey (2013), Mapping 3-D mantle electrical conductivity from space: A new 3-D inversion scheme based on analysis of matrix Q-responses, in Geophysical Journal International
, 197(2), 768-784.
Olsen Nils, Friis-Christensen Eigil, Floberghagen Rune, Alken Patrick, Alken Patrick, Beggan Ciaran D., Chulliat Arnaud, Doornbos Eelco, Da Encarnação João Teixeira, Hamilton Brian, Hulot Gauthier, Van Den Ijssel Jose, Kuvshinov Alexey, Lesur Vincent, Lühr Hermann, Macmillan Susan, Maus Stefan, Noja Max, Olsen Poul Erik H, Park Jaeheung, Plank Gernot, Püthe Christoph, Rauberg Jan, Ritter Patricia, Rother Martin (2013), The Swarm satellite constellation application and research facility (SCARF) and Swarm data products, in Earth, Planets and Space
, 65(11), 1189-1200.
Püthe Christoph, Kuvshinov Alexey (2013), Towards quantitative assessment of the hazard from space weather. Global 3-D modellings of the electric field induced by a realistic geomagnetic storm, in Earth, Planets and Space
, 65(9), 1017-1025.
The study of lateral variability in physical properties of Earth's mantle using geophysical methods is a topic of present-day fundamental science. It gives insight into geodynamic processes such as mantle convection, the fate of subducting slabs and the origin of continents. Global seismic tomography provides today a variety of three-dimensional (3-D) mantle velocity models that can be interpreted in terms of cratonic roots, mantle plumes and slab graveyards. The goal of global electromagnetic (EM) induction studies is to identify complementary large-scale spatial variations (3-D structures) in the electrical conductivity of the mantle. This is an important issue since conductivity reflects the connectivity of constituents such as fluids, partial melt, and volatiles, while seismology ascertains bulk mechanical properties.To date only ground-based data from a global network of geomagnetic observatories have been using to obtain global 3-D images of mantle conductivity. But since the observatories are sparsely and irregularly distributed with only a few in oceanic regions and the southern hemisphere, reliable images of 3-D variations of mantle conductivity in these regions can hardly be obtained with the use of observatory data alone. However, in contrast to ground-based data, satellite-borne measurements provide excellent spatial data coverage by dint of their almost polar orbits. With the European Space Agency multi-satellite mission Swarm (to be launched in 2012), and with the European-Chinese multi-satellite initiative CGM (planned to be launched in 2016 by the Chinese Academy of Sciences), the possibility of obtaining trustworthy global images of 3-D mantle heterogeneities, especially in the regions with poor ground-based coverage, comes into reach. Moreover, mapping of 3-D electrical conductivity of the Earth’s mantle has been identified as one of the main scientific objectives both for the Swarm and CGM constellation missions. But satellite data analysis is much more challenging compared to observatory data analysis since satellites typically travel with a speed of 7-8 km/s and thus measure a mixture of temporal and spatial changes of the geomagnetic field. The forthcoming mission Swarm has initiated efforts to develop methodologies for recovering 3-D electrical conductivity variations from space. One of the promising concepts which appeared recently relies on estimation and inversion of the so-called matrix Q-responses. However, to date this concept exists only as a theoretical possibility. The main objective of this project is to convert the concept into an efficient and useful tool. The project is self-contained and it is designed to be suitable for 3-year study leading to a PhD. The PhD student will be guided by the PI’s (PD Dr. Alexey Kuvshinov) expertise in the development of inverse and forward solutions for other, but similar applications. Expected outputs from the project are: (a) a multi-variate time series analysis code to estimate matrix Q-responses; (b) a novel and fast 3-D global induction inverse code based on the analysis of these responses; (c) a global 3-D conductivity model of the Earth’s mantle. Both the codes and 3-D model will be made available to be used to achieve the goals of aforementioned multi-satellite geomagnetic missions.