Book Review     

Andrzej Icha 《Pure and Applied Geophysics》2013,170(11):2001-2002

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The use of fuzzy sets in the evaluation of the environment of coastal waters     

Jacek Andrzej Urbanski 《International journal of geographical information science》2013,27(7):723-730

This paper advocates the use of GIS for the evaluation of the vulnerability of coastal waters and presents a method for mapping their vulnerability to algal blooms. The method incorporates probability mapping of parameters used to describe coastal waters and fuzzy sets. To allow the modelling of processes where some components cannot substitute for other components the 'no trade off' convex combination formula is proposed. The maps of vulnerability for the Gulf of Gdansk, which were created using this method, may be used to find out which rivers and water discharges play a dominant role in eutrophication.  相似文献   

Magneto- and biostratigraphy of the Jurassic/Cretaceous boundary in the Lókút section (transdanubian range,Hungary)     

Jacek Grabowski  János Haas  Emö Márton  Andrzej Pszczółkowski 《Studia Geophysica et Geodaetica》2010,54(1):1-26

Jurassic-Cretaceous sediments of Transdanubian Range in Northern Hungary mostly retain their primary magnetizations and are suitable for detailed bio- and magnetostratigraphic studies. The Lókút section, 13 m in thickness, is localized in the central part of the Transdanubian Range. It contains the Jurassic/Cretaceous boundary in pelagic carbonate facies. Although the colour of the rocks changes from reddish-pinkish in the bottom to almost white at the top of the section, magnetite was identified as a magnetic carrier without evidence of hematite. Integrated bio- and magnetostratigraphical investigations resulted in construction of chronostratigraphical scheme. The section, embraces magnetozones from M21r to M18r, of upper Lower Tithonian (Parastomiosphaera malmica Zone) to Lower Berriasian age (Calpionella alpina Subzone). Sedimentation rate of pelagic limestones increased from 1–3 m/My during Tithonian to 5–7 m/My during Berriasian. The sedimentation rate and its changes up the section are comparable to those from the Jurassic/Cretaceous boundary sections of Trento plateau (Southern Alps, Italy) — sedimentary environments of Trento plateau and central Transdanubian Range in that time might be similar. Sedimentation rate within Umbrian Apennine basins and Križna unit in the Western Tatra Mts. seems significantly higher. Analysis of rock magnetic parameters reveals that detrital input was much lower into the Lókút section than into Križna basin in the Tatra Mts. (Zliechov trough). Increase of sedimentation rate occurs in both sections in the Upper Tithonian — Lower Berriasian. It coincides with the onset of calpionellid limestone facies and is related to increased productivity of calcareous micro- and nannoplankton. Detailed correlation of both sections basing on rock magnetic parameters and susceptibility changes is, however, not possible. They are dependent mostly on the local sedimentary conditions (Bakony Mts. — deep water plateau; Križna unit — deep water trough) and correlation with any “global” paleoenvironmental (climatic, eustatic) trends is not straightforward.  相似文献   

New Methods for Modeling Laterolog Resistivity Corrections   总被引：1，自引：1，他引：0  

Jadwiga Anna Jarzyna  Adam Cichy  Dezső Drahos  Attila Galsa  Maria Joanna Bała  Andrzej Ossowski 《Acta Geophysica》2016,64(2):417-442

The paper presents methods for laterolog response modeling. In Coulomb’s charges method, Laplace’s equation is solved for the electric field distribution in rock medium with internal boundaries between different resistivity layers. There, the boundary problem is reduced to Fred-holm integral equation of the second kind. The second method uses a finite element array to model apparent resistivity from laterolog. The task is treated as DC problem and the Laplace equation is solved numerically. The presented methods were applied to borehole data covering a typical stratigraphie section of the Fore-Sudetic Monocline in southwestern Poland. Apparent resistivity was calculated using the Coulomb’s charges method and alternatively modeled using a finite element method which gave similar results. Then, a series of linear corrections for borehole, shoulder bed, and filtration effects for apparent resistivity obtained by the Coulomb’s charges method demonstrated the feasibility of calculating true resistivity of virgin and invaded zones. The proposed methods provide a flexible solution in modeling which can be adapted to other logs.  相似文献   

Prospects for Solar and Space Weather Research with Polish Part of the LOFAR Telescope   总被引：1，自引：1，他引：0  

Bartosz P. Dąbrowski  Andrzej Krankowski  Leszek Błaszkiewicz  Hanna Rothkaehl 《Acta Geophysica》2016,64(3):825-840

The LOw-Frequency ARray (LOFAR) is a new radio interferometer that consists of an array of stations. Each of them is a phase array of dipole antennas. LOFAR stations are distributed mostly in the Netherlands, but also throughout Europe. In the article we discuss the possibility of using this instrument for solar and space weather studies, as well as ionosphere investigations. We are expecting that in the near future the LOFAR telescope will bring some interesting observations and discoveries in these fields. It will also help to observe solar active events that have a direct influence on the near-Earth space weather.  相似文献   

Application of Gravity Gradients in the Process of GOCE Orbit Determination     

Andrzej Bobojć 《Acta Geophysica》2016,64(2):521-540

The possibility of improving the Gravity Field and Steady-State Ocean Circulation Explorer (GOCE) mission satellite orbit using gravity gradient observations was investigated. The orbit improvement is performed by a dedicated software package, called the Orbital Computation System (OCS), which is based on the classical least squares method. The corrections to the initial satellite state vector components are estimated in an iterative process, using dynamic models describing gravitational perturbations. An important component implemented in the OCS package is the 8th order Cowell numerical integration procedure, which directly generates the satellite orbit. Taking into account the real and simulated GOCE gravity gradients, different variants of the solution of the orbit improvement process were obtained. The improved orbits were compared to the GOCE reference orbits (Precise Science Orbits for the GOCE satellite provided by the European Space Agency) using the root mean squares (RMS) of the differences between the satellite positions in these orbits. The comparison between the improved orbits and the reference orbits was performed with respect to the inertial reference frame (IRF) at J2000.0 epoch. The RMS values for the solutions based on the real gravity gradient measurements are at a level of hundreds of kilometers and more. This means that orbit improvement using the real gravity gradients is ineffective. However, all solutions using simulated gravity gradients have RMS values below the threshold determined by the RMS values for the computed orbits (without the improvement). The most promising results were achieved when short orbital arcs with lengths up to tens of minutes were improved. For these short arcs, the RMS values reach the level of centimeters, which is close to the accuracy of the Precise Science Orbit for the GOCE satellite. Additional research has provided requirements for efficient orbit improvement in terms of the accuracy and spectral content of the measured gravity gradients.  相似文献   

Book Review     

Andrzej Icha 《Pure and Applied Geophysics》2012,169(10):1921-1921

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Variable infiltration and river flooding resulting in changing groundwater quality – A case study from Central Europe     

Konrad Miotliński  Dieke Postma  Andrzej Kowalczyk 《Journal of Hydrology》2012

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Results of the application of tropospheric corrections from different troposphere models for precise GPS rapid static positioning   总被引：1，自引：0，他引：1  

Paweł Wielgosz  Jacek Paziewski  Andrzej Krankowski  Krzysztof Kroszczyński  Mariusz Figurski 《Acta Geophysica》2012,60(4):1236-1257

In many surveying applications, determination of accurate heights is of significant interest. The delay caused by the neutral atmosphere is one of the main factors limiting the accuracy of GPS positioning and affecting mainly the height coordinate component rather than horizontal ones. Estimation of the zenith total delay is a commonly used technique for accounting for the tropospheric delay in static positioning. However, in the rapid static positioning mode the estimation of the zenith total delay may fail, since for its reliable estimation longer observing sessions are required. In this paper, several troposphere modeling techniques were applied and tested with three processing scenarios: a single baseline solution with various height differences and a multi-baseline solution. In specific, we introduced external zenith total delays obtained from Modified Hopfield troposphere model with standard atmosphere parameters, UNB3m model, COAMPS numerical weather prediction model and zenith total delays interpolated from a reference network solution. The best results were obtained when tropospheric delays derived from the reference network were applied.  相似文献   

Effects of the stellar wind on X-ray spectra of Cygnus X-3     

Anna Szostek  Andrzej A. Zdziarski 《Monthly notices of the Royal Astronomical Society》2008,386(2):593-607

We study X-ray spectra of Cyg X-3 from BeppoSAX , taking into account absorption and emission in the strong stellar wind of its companion. We find the intrinsic X-ray spectra are well modelled by disc blackbody emission, its upscattering by hot electrons with a hybrid distribution, and by Compton reflection. These spectra are strongly modified by absorption and reprocessing in the stellar wind, which we model using the photoionization code cloudy . The form of the observed spectra implies the wind is composed of two phases. A hot tenuous plasma containing most of the wind mass is required to account for the observed features of very strongly ionized Fe. Small dense cool clumps filling ≲0.01 of the volume are required to absorb the soft X-ray excess, which is emitted by the hot phase but not present in the data. The total mass-loss rate is found to be  (0.6–1.6) × 10⁻⁵ M_⊙ yr⁻¹  . We also discuss the feasibility of the continuum model dominated by Compton reflection, which we find to best describe our data. The intrinsic luminosities of our models suggest that the compact object is a black hole.  相似文献