Snow Accumulation on a Small High‐Arctic Glacier Svenbreen: Variability and Topographic Controls          下载免费PDF全文

Jakub Małecki 《Geografiska Annaler: Series A, Physical Geography》2015,97(4):809-817

One of the main controls on the net mass change of land‐terminating Arctic glaciers is the magnitude and distribution of snow accumulation. In Dickson Land, region of Svalbard with the greatest distance to the sea, the issue has not been receiving much scientific attention for decades. In this paper, new snow accumulation data are presented from Svenbreen in Dickson Land from end‐of‐winter surveys. The measured winter balance was 0.42 ± 0.15 m w.e. in 2010, 0.50 ± 0.10 m w.e. in 2011 and 0.62 ± 0.10 cm w.e. in 2012. Snow depth and water equivalent have been analysed in the background of altitude, slope and aspect extracted from the digital elevation model of the glacier. On steep northern slopes (>15°) accumulation was the highest, whereas it was decreased on southern slopes with moderate inclination (9–12°). Elevation, which on many glaciers proved to be highly correlated with snow depth, explained only 17–34% of snow depth variability due to complex interplay between local climate and geometry of a small valley.  相似文献   

Eemian environmental changes recorded in lake deposits from Rzecino (NW Poland): Cladocera,isotopic and selected geochemical data     

Monika Niska  Joanna Mirosław-Grabowska 《Journal of Paleolimnology》2015,53(1):89-105

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Different Borders‐Different Cooperation? Transborder Cooperation in Poland          下载免费PDF全文

Sylwia Dołzbłasz  Andrzej Raczyk 《Geographical review》2015,105(3):360-376

The aim of this paper was to analyze the role of border and borderland type in transborder cooperation. To this end, 591 projects under six Interreg IIIA Programs in which Polish border regions participated from 2004 to 2006 were examined. These programs were compared to identify the various factors influencing projects in different border regions. Although research on cooperation usually focuses on a national scale, actual cooperation depends largely on regional and local conditions, which are the focus of this study. Despite a common legal and institutional framework, the Interreg projects were not all realized in the same way. Different local conditions had impacts on programs and implementation. Therefore, the effectiveness and achievement of transborder cooperation objectives depended on the modification of each program to specific regional conditions.  相似文献   

Search of visually similar microscopic rock images     

Magdalena Ładniak  Mariusz Młynarczuk 《Computational Geosciences》2015,19(1):127-136

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Testing the anelastic nonhydrostatic model EULAG as a prospective dynamical core of a numerical weather prediction model Part II: Simulations of supercell     

Marcin J. Kurowski  Bogdan Rosa  Michał Z. Ziemiański 《Acta Geophysica》2011,59(6):1267-1293

The anelastic nonhydrostatic model EULAG is a candidate for the future dynamical core of a numerical weather prediction model. Achieving such an objective requires a number of experiments focused on testing correctness of the solutions and robustness of the solver. In the spirit of this idea, a set of tests related to standard atmospheric problems was performed, of which the two regarding development and evolution of a supercell were employed as benchmarks of moist dynamics of the model. Their results are discussed in this paper. Development and evolution of a stormsystem with a set of characteristic features such as stormsplitting along with the generation of horizontal vorticity and cold pool formation is investigated. In addition, the influence of domain geometry, boundary conditions and subgrid-scale mixing is examined.  相似文献   

Evaluation of electric parameters of anisotropic sandy-shaly Miocene formations on the basis of resistivity logs   总被引：1，自引：1，他引：0  

Maria Bała 《Acta Geophysica》2011,59(5):954-966

In this paper, electrical properties of an anisotropic rock formation are discussed. Electrical anisotropy parameters, i.e., horizontal resistivity, R _H , and vertical resistivity, R _V , and anisotropy coefficient in the sandyshaly Miocene formation, are determined on the basis of induction logs and laterologs. Graphs of R _V = f(R _H ) calculated for different resistivities of sandstones and shales and variable volumes of those two components allow us to conclude about the correctness of the applied method for determining the resistivity parameters of autochthonous Miocene formations.  相似文献   

<Emphasis Type="Italic">Salvinia natans</Emphasis> in medieval wetland deposits in Gdańsk,northern Poland: evidence for the early medieval climate warming     

Joanna Święta-Musznicka  Małgorzata Latałowa  Józef Szmeja  Monika Badura 《Journal of Paleolimnology》2011,45(3):369-383

Large numbers of sub-fossil remains of the aquatic fern Salvinia natans (L.) All. have been found in several early medieval sites in Gdańsk, N. Poland. This record indicates a population expansion of this species around 7th–8th century A.D., similar to the recently observed rapid spread and high population dynamics of S. natans in northern Poland, which recent studies have attributed to climate warming. Our results suggest that in the Vistula deltaic area the S. natans expansion in the Early Middle Ages (7th–8th century A.D.) was similarly stimulated by climate warming, while its subsequent decline was mainly due to climate cooling, especially during the Little Ice Age. Warmer winters and springs and a longer growing season seem to be the most important factors forcing the expansion of S. natans in medieval times. According to our data, the co-occurrence of S. natans with other aquatic plant species was similar in both the medieval and present-day vegetation. Also, the high density of S. natans in the medieval population caused impoverishment of the local ecosystems in a way that has been observed in recent water bodies affected by invasive pleustophytes (free-floating plants).  相似文献   

GPR and aerial imageries to identify the recent historical course of the Obra River and spatial extent of Obrzańskie Lake, altered by hydro-technical works     

Marcin Słowik 《Environmental Earth Sciences》2013,70(3):1277-1295

Ground penetrating radar (GPR) measurements have been conducted to retrace the natural course of the Obra River and changes of spatial extent of Obrzańskie Lake (western Poland). The Obra River valley was subjected to intensive anthropogenic transformation. Three artificial canals were constructed here in the beginning of the nineteenth century. The GPR surveys were done using a georadar MALA ProEx equipped with 250 MHz antenna. The measurement was verified by coring and analyses of historical maps, aerial photographs, and satellite images. The research has shown that there are at least three elongated depressions preserved in the modern land surface near the village of Solec, situated in the middle course of the valley. Several structures suggesting functioning of a multi-channel pattern in the past have been detected inside and in the vicinity of the depressions. Filling the channels with silts and peats might have been the effect of flow deceleration caused by the construction of the Obra Canals. Moreover, situation of two of the retraced depressions suggests that the landforms might be the remains of a river bed disappearing in wetlands. Further studies including groundwater flux measurements in the area between the depressions are needed to confirm such hypothesis. Furthermore, the study allowed retracing the spatial extent of Obrzańskie Lake. The sediment structures detected by the GPR measurements and calibrated with coring were interpreted to be the traces of the lake shoreline. The interpretation was supported by the findings inferred from aerial and satellite images. It was shown that Obrzańskie Lake had had at least three islands and had been directly connected with a network of braided channels before the anthropogenic intervention. The spatial extent of the lake was significantly altered by the construction of the North Obra Canal. Disconnecting the lake from the Canal resulted in more than 50 % decrease of the lake surface.  相似文献   

Comment on the Seismic Method Depth-Recursive Tomography on Grid (DRTG) Developed by Miroslav Novotný and Recently Published in Three Papers in Surveys in Geophysics     

Pavla Hrubcová  Piotr Środa  Václav Vavryčuk  Vladislav Babuška  Marek Grad 《Surveys in Geophysics》2013,34(4):521-529

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Changes in the biota and sediments of glacial Lake Koźmin, Poland, during the late Saalian (Illinoian)     

Dominik Pawłowski  Beata Gruszka  Hanna Gallas  Joanna Petera-Zganiacz 《Journal of Paleolimnology》2013,49(4):679-696

Upper Saalian (Illinoian) glaciolacustrine deposits in central Poland, preserved in a tectonic graben, were exposed in an opencast lignite mine and investigated using sedimentological and micro-paleontological methods. The extraglacial lake sediments provide the first records of late Saalian cladoceran communities in central Europe, recovered from glaciolacustrine deposits. Sedimentation was dominated by a supply of clastics that fluctuated with the seasons, forming rhythmites. In addition to seasonal cyclicity, sedimentary and environmental conditions changed every several years to decades, with periods of increased inflow to the lake delivering sandy material, and periods of almost stagnant water dominated by suspension settling. The sediments contain Cladocera assemblages that indicate the lake was initially deep, oligotrophic, and filled with moderately cold water. Changes in Cladocera community composition and abundance were perhaps responses to climate seasonality. Zones without Cladocera were associated with seasons of higher inflow and sediment supply, and directly or indirectly, with tectonic activity in the graben. Earthquakes, documented by the presence of seismites, caused not only deformation of unconsolidated lake-bottom sediments, but possibly also changes in habitat characteristics. Combined sedimentological and biological data were used to infer the lake’s history and show that deposits of glaciolacustrine lakes can be used as indicators of past ecological and climate changes.  相似文献