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41.
Grzegorz Lizurek Beata Plesiewicz Pawe? Wiejacz Jan Wiszniowski Jacek Trojanowski 《Acta Geophysica》2013,61(1):26-36
The earthquake of magnitude M L = 3:8 (EMSC) took place on Friday, 6 January 2012, north-east of the town of Jarocin in Wielkopolska Region, Poland. The only historical information about past earthquakes in the region was found in the diary from 1824; apart of it, there was a seismic event noticed in the vicinity of Wielkopolska in 1606 (Pagaczewski 1982). The scope of this paper is to describe the 6 January 2012 event in view of instrumental seismology, macroseismic data analysis and known tectonics of the region, which should be useful in future seismic hazard analysis of Poland. 相似文献
42.
Iwona S. Stachlewska Michał Piądłowski Szymon Migacz Artur Szkop Anna J. Zielińska Paweł L. Swaczyna 《Acta Geophysica》2012,60(5):1386-1412
Jenoptik’s CHM 15k ceilometer was used to monitor the vertical structure of the atmospheric boundary layer (ABL) over Warsaw, from 2008 until 2011, on Mondays and Thursdays, in 24h periods. Hereby, we present an assessment of the signal-to-noise ratio along with a sensitivity study of signal smoothing methods developed in-house. With the proposed averaging, ceilometer attenuated-backscatter signals reached the high troposphere, which makes this sensor competitive to a single-wavelength elastic lidar. The smoothed signals were employed as an input for algorithms developed to automatically detect the ABL height, clouds, fog, and precipitation in the lower troposphere. The classification of weather conditions was validated by the METAR reports from the Warsaw Airport. The obtained ABL heights were compared to those assessed from radio-soundings from a nearby meteorological station WMO12374 in Legionowo. An inter-comparison of the ABL heights, derived by using the Jenoptik’s automated routine against the in-house developed algorithms, is in favor of the latter. The presented four annual cycles of the ABL height, obtained with various derivative-based methods, are the first such long-term results reported using the CHM 15k sensor in Eastern Europe. 相似文献
43.
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
44.
Monika B. Kalinowska Paweł M. Rowiński Janusz Kubrak Dorota Mirosław-Świątek 《Acta Geophysica》2012,60(1):214-231
The problem of two-dimensional mathematical modelling of heated cooling water discharges into running waters is considered
in the paper. Two models — one for the evaluation of 2D turbulent velocity field and the other, developed by authors of the
study, for 2D heat transport in open-channels — were used in the calculations. Relevant scenarios of the spread of heated
water discharged from a designed gas-stem power plant to be constructed at the Vistula River were presented. Environmentally
most friendly variant of the discharge of the thermal pollution was selected from among four various variants. 相似文献
45.
Floods at the northern foothills of the Tatra Mountains — A Polish-Swiss research project 总被引：1，自引：1，他引：0
Zbigniew W. Kundzewicz Markus Stoffel Ryszard J. Kaczka Bartłomiej Wyżga Tadeusz Niedźwiedź Iwona Pińskwar Virginia Ruiz-Villanueva Ewa Łupikasza Barbara Czajka Juan Antonio Ballesteros-Canovas Łukasz Małarzewski Adam Choryński Karolina Janecka Paweł Mikuś 《Acta Geophysica》2014,62(3):620-641
The present paper introduces the topical area of the Polish-Swiss research project FLORIST (Flood risk on the northern foothills of the Tatra Mountains), informs on its objectives, and reports on initial results. The Tatra Mountains are the area of the highest precipitation in Poland and largely contribute to flood generation. The project is focused around four competence clusters: observation-based climatology, model-based climate change projections and impact assessment, dendrogeomorphology, and impact of large wood debris on fluvial processes. The knowledge generated in the FLORIST project is likely to have impact on understanding and interpretation of flood risk on the northern foothills of the Tatra Mountains, in the past, present, and future. It can help solving important practical problems related to flood risk reduction strategies and flood preparedness. 相似文献
46.
Robert J. Bialik Mikołaj Karpiński Agnieszka Rajwa Bartłomiej Luks Paweł M. Rowiński 《Acta Geophysica》2014,62(6):1413-1434
This paper presents results of a field investigation conducted to examine the bed sediment, riverbed morphology and flow structure over dunes in natural and regulated channels. Field measurements using an acoustic Doppler current profiler (ADCP) have been carried out on two parts of lowland Wilga River in Poland. It is shown that the bedforms with a low angle of lee side develop more frequently than asymmetrical dunes with high lee-side angles, which are mostly associated with the occurrence of local scours and river meanders. Wavenumber analysis of bed elevation confirms the existence of scaling region in the longitudinal wavenumber spectrum, with “?3” scaling exponents for the natural and regulated channels as well. Moreover, the results of flow velocity field are presented in the form of a 2-D streamwise-vertical vector field, showing several similarities to previous laboratory and field investigations conducted on much deeper rivers than the Wilga. The experimental campaign and methods used to obtain the results are also presented briefly. In addition, a short database of fluvial dunes statistics is provided. 相似文献
47.
Multiscale interaction between monsoonal circulation and the local topography causes the southern front of the Darjeeling–Bhutan Himalaya to receive one of the highest annual rainfalls (3000–6000 mm) and most frequent heavy rains (up to 800 mm day?1) along the whole southern Himalayan margin. An examination of the patterns of annual rainfall, rainfall concentration, overland flow generation and slope instability indices in the Darjeeling–Bhutan Himalaya for 1986–2015 indicates that the mountain front disturbs rainfall gradient between the Bay of Bengal and the Tibetan Plateau. The results show that the precipitation concentration indices are lowest at the Himalayan front where the annual rainfall and the number of rainy days are highest. The Himalayan front has the highest predisposition to produce overland flow compared to adjacent foreland and the mountain interior. The average probability of the rainfall initialising the shallow landslides increases from 0.6% for a 1-day rainfall threshold of 144 mm to 6.1% for a 4-day rainfall threshold of 193 mm in the study area. The highest probability (up to 10%) of 2-day and longer low-intensity storms at the mountain front indicate that its area is threatened with particularly larger and deeper landslides. The multivariate regression analysis reveals statistically significant linear relationships of rainfall hazard indices with elevation and the distance to the mountain front in the mountain foreland and Himalaya, respectively. Regionally, the Darjeeling Himalaya reveals lower values of rainfall hazard indices, in comparison to the Bhutan Himalaya. 相似文献
48.
The paper presents the method of local magnitude determination used at Polish seismic stations to report events originating
in one of the four regions of induced seismicity in Poland or its immediate vicinity. The method is based on recalculation
of the seismic moment into magnitude, whereas the seismic moment is obtained from spectral analysis. The method has been introduced
at Polish seismic stations in the late 1990s but as of yet had not been described in full because magnitude discrepancies
have been found between the results of the individual stations. The authors have performed statistics of these differences,
provide their explanation and calculate station corrections for each station and each event source region. The limitations
of the method are also discussed. The method is found to be a good and reliable method of local magnitude determination provided
the limitations are observed and station correction applied. 相似文献
49.
Heavy metals in sediments as evidence for recent pollution and quasi-estuarine processes: an example from Lake Druzno,Poland 总被引：1，自引：0，他引：1
Wojciech Tylmann Roman Gołębiewski Piotr Paweł Woźniak Karolina Czarnecka 《Environmental Geology》2007,53(1):35-46
This article presents the results of a geochemical investigation of sediments from Lake Druzno (northern Poland), a reservoir
fed by freshwater from the catchment, with periodic input of brackish water from Vistula Lagoon. This study analyzed the spatial
variation in heavy metal content in surface sediments as well as the temporal changes in metal content in two sediment cores
dated using the 210Pb method. In the surface sediments, the highest metal concentrations were recorded in the northern part of the lake, with
lower concentrations in the central and southern parts. Absolute values of metal concentrations in the cores were low, but
normalization with respect to Al showed an increase during the second half of the 20th century. Mean enrichment factors (EF)
in sediments from the second half of the 20th century ranged from insignificant (1–1.2) for Fe to (1.55–3.3) for Cu, Cd, Pb
and Zn. The sediments deposited before 1950 had lower EF values (>1.5) and had low variability. Results from both the surface
sediments and the cores indicate that the main source of lake pollution is brackish water intrusion from the Vistula Lagoon
via the contaminated River Elbląg. 相似文献
50.
Earthquake of November 30, 2004, in Podhale region, southern Poland, was of unexpectedly big size in this area of weak seismicity.
As Poland is considered a country of low seismicity, the earthquake has caused concern about seismic hazard in Poland, especially
since it took place shortly after the even more unexpected Kaliningrad Region, Russia, earthquakes of September 21, 2004,
that inflicted minor damage in northern Poland. The paper presents the findings on the Podhale earthquake which reached macroseismic
intensity up to 7 and magnitude 4.7 (m
b
; ISC). The event was felt up to a distance of about 100 km and inflicted slight damage to buildings in its narrow epicentral
area, thus evidencing its relatively shallow depth. The quake has been located near the village of Skrzypne, about 15 km west-southwest
of the district capital Nowy Targ. The source mechanism has been found to be of dip slip normal fault type, although a problem
remains of association of this mechanism with known tectonic dislocations in the region. The earthquake has been followed
by a long series of aftershocks. Their distribution in time is also studied and the biggest aftershocks have been located. 相似文献