Analysis and usage of linear relationships between the magnetic field components recorded by INTERMAGNET     

Krzysztof Nowożyński  Katarzyna Ślęzak 《Acta Geophysica》2013,61(3):511-534

An analysis of linear relationships between the ground-level components of the Earth’s magnetic field measured at different sites is a relatively new topic compared to the analysis of data at a single location. The data collected by the INTERMAGNET observation network provide perfect set of data to which this analysis can be used. An important tool in this analysis may be developing a method of determination of the impulse response for linear systems in the time domain. An advantage of calculations in the time domain over the generally known and applied methods in the frequency domain is the possibility of determining prediction of output signals. By that, simultaneously with the analysis of linear relationships, a tool for recovering missing records in incomplete observation data is obtained. Filling-in the missing data may increase interest and possibility of using the observational data by researchers experimenting with the analysis in the frequency domain where gaps in data records are a significant limitation.  相似文献   

Impact of loading displacements on SLR-derived parameters and on the consistency between GNSS and SLR results   总被引：5，自引：4，他引：1  

Krzysztof Sośnica  Daniela Thaller  Rolf Dach  Adrian Jäggi  Gerhard Beutler 《Journal of Geodesy》2013,87(8):751-769

Displacements of the Earth’s surface caused by tidal and non-tidal loading forces are relevant in high-precision space geodesy. Some of the corrections are recommended by the international scientific community to be applied at the observation level, e.g., ocean tidal loading (OTL) and atmospheric tidal loading (ATL). Non-tidal displacement corrections are in general recommended not to be applied in the products of the International Earth Rotation and Reference Systems Service, in particular atmospheric non-tidal loading (ANTL), oceanic and hydrological non-tidal corrections. We assess and compare the impact of OTL, ATL and ANTL on SLR-derived parameters by reprocessing 12 years of SLR data considering and ignoring individual corrections. We show that loading displacements have an influence not only on station long-term stability, but also on geocenter coordinates, Earth Rotation Parameters, and satellite orbits. Applying the loading corrections reduces the amplitudes of annual signals in the time series of geocenter and station coordinates. The general improvement of the SLR station 3D coordinate repeatability when applying OTL, ATL and ANTL corrections are 19.5 %, 0.2 % and 3.3 % respectively, w.r.t. the solutions without loading corrections. ANTL corrections play a crucial role in the combination of optical (SLR) and microwave (GNSS, VLBI, DORIS) space geodetic observation techniques, because of the so-called Blue-Sky effect: SLR measurements can be carried out only under cloudless sky conditions—typically during high air pressure conditions, when the Earth’s crust is deformed, whereas microwave observations are weather-independent. Thus, applying the loading corrections at the observation level improves SLR-derived products as well as the consistency with microwave-based results. We assess the Blue-Sky effect on SLR stations and the consistency improvement between GNSS and SLR solutions when ANTL corrections are included. The omission of ANTL corrections may lead to inconsistencies between SLR and GNSS solutions of up to 2.5 mm for inland stations. As a result, the estimated GNSS–SLR coordinate differences correspond better to the local ties at the co-located stations when applying ANTL corrections.  相似文献   

New induction sounding tested in Central Europe     

Vladimir Yu. Semenov  Borys Ladanivskyy  Krzysztof Nowożyński 《Acta Geophysica》2011,59(5):815-832

The hourly data of nine geomagnetic observatories situated in Central Europe have been analyzed using the generalized magnetovariation (GMV) method designed recently for induction soundings of inhomogeneous media. In this method, impedance is one of transfer functions in the differential relation between spectra of the magnetic components and their derivatives. The peculiarity of this impedance is its correspondence to the magnetotelluric one estimated from the linear relations. Three transfer functions have been estimated simultaneously for data of geomagnetic observatories, using three different routines working in the period range from three hours up to two days. Noises in the source field components have been compared with noise in the estimated plane field divergence. The multivariate errors-in-variables method was used to extract spatially and temporally coherent geomagnetic field structure from the partially incoherent geomagnetic variations. This method allows estimating reliably impedances and gradient tippers for each observatory, taking into consideration the Earth’s sphericity. The obtained responses have been used for induction soundings and for detecting a deep inhomogeneity in the region.  相似文献   

The petrogenesis of granitoid rocks unusually rich in apatite in the Western Tatra Mts. (S-Poland, Western Carpathians)     

Krzysztof Szopa  Aleksandra Gawęda  Axel Müller  Magdalena Sikorska 《Mineralogy and Petrology》2013,107(4):609-627

In the bottom part of the tongue-shaped, layered granitoid intrusion, exposed in the Western Tatra Mts., apatite-rich granitic rocks occur as pseudo-layers and pockets between I-type hybrid mafic precursors and homogeneous S-type felsic granitoids. The apatite-rich rocks are peraluminous (ASI?=?1.12–1.61), with P₂O₅ contents ranging from 0.05 to 3.41 wt.% (<7.5 vol.% apatite), shoshonitic to high-K calc-alkaline. Apatite is present as long-prismatic zoned crystals (Ap₁) and as large xenomorphic unzoned crystals (Ap₂). Ap₁ apatite and biotite represent an early cumulate. Feldspar and Ap₂ textural relations may reflect the interaction of the crystal faces of both minerals and support a model based on local saturation of (P, Ca, F) versus (K, Na, Al, Si, Ba) in the border zones. Chondrite-normalized REE patterns for the apatite rocks and for pure apatite suggest apatite was a main REE carrier in these rocks. Minerals characteristics and the whole rock chemistry suggest both reduced S-type and I-type magma influenced the apatite-rich rocks. The field observations, mineral and rock chemistry as well as mass-balance calculations point out that the presence of apatite-rich rocks may be linked to the continuous mixing of felsic and mafic magmas, creating unique phosphorus- and aluminium-rich magma portions. Formation of these rocks was initially dominated by the complex flowage-controlled and to some extent also gravity-driven separation of early-formed zoned minerals and, subsequently, by local saturation in the border zones of growing feldspar and apatite crystals. Slow diffusion in the phosphorus-rich magma pockets favoured the local saturation and simultaneous crystallization of apatite and feldspars in a crystal-ladden melt.  相似文献   

Part II. Discontinuous Galerkin method applied to a single phase flow in porous media     

Béatrice Riviè;re  Mary F. Wheeler  Krzysztof Banaś 《Computational Geosciences》2000,4(4):337-349

Discontinuous Galerkin numerical simulations of single phase flow problem are described in this paper. The simulations show the advantages of using discontinuous approximation spaces. hp convergence results are obtained for smooth solutions. Unstructured meshes and unsmooth solutions are also considered.  相似文献