The urban heat island in the city of Poznań as derived from Landsat 5 TM

Deforestation is expanding and accelerating into the remaining areas of undisturbed forest, and the quality of the remaining forests is declining today. Assessing the climatic impacts of deforestation can help to rectify this alarming situation. In this paper, how historical deforestation may affect global climate through interactive ocean and surface albedo is examined using an Earth system model of intermediate complexity (EMIC). Control and anomaly integrations are performed for 1000 years. In the anomaly case, cropland is significantly expanded since AD 1700. The response of climate in deforested areas is not uniform between the regions. In the background of a global cooling of 0.08 °C occurring with cooler surface air above 0.4 °C across 30° N to 75° N from March to September, the surface albedo increase has a global cooling effect in response to global-scale replacement of forests by cropland, especially over northern mid-high latitudes. The northern mid-latitude (30° N–60° N) suffers a prominent cooling in June, suggesting that this area is most sensitive to cropland expansion through surface albedo. Most regions show a consistent trend between the overall cooling in response to historical deforestation and its resulting cooling due to surface albedo anomaly. Furthermore, the effect of the interactive ocean on shaping the climate response to deforestation is greater than that of prescribed SSTs in most years with a maximum spread of 0.05 °C. This difference is more prominent after year 1800 than that before due to the more marked deforestation. These findings show the importance of the land cover change and the land surface albedo, stressing the necessity to analyze other biogeophysical processes of deforestation using interactive ocean.     

TraceeElements in Leccinum scabrum mushrooms and topsoils from Kłodzka Dale in Sudety Mountains, Poland

In the current study, we determined concentrations and transfer rates of Ag, Al, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Na, Ni, Pb, P, Rb, Sr and Zn to Brown Birch Scaber Stalks (Leccinum scabrum) mushrooms emerged in the area of Sudety Mountains (Sudetes) in Poland. Fruiting bodies and topsoil samples beneath L. scabrum were collected form the K odzka Dale. The trace elements were determined using validated method and inductively coupled plasma - atomic emission spectroscopy (ICP-AES) for final measurement. Mushrooms contained Ag, Cr, Hg, Co, Ni and Sr at < 1.0 μg/g dry weight; Ba and Pb at ~1.0 μg/g dw; Cd at < 5 μg/g dw; Cu and Mn at > 10 μg/g dw; Al and Ca at ~100 μg/g dw; Fe, Na, Rb and Zn at 100 to 500 μg/g dw, Mg at ~1,000 μg/g dw; P at ~5,000 μg/g dw and K at ~30,000 μg/g dw. Ca, Mn and Ni were nearly equally distributed between stipes and caps; stipes compared to caps were enriched in Ba, Na and Sr, while caps were enriched in Ag, Al, Cd, Co, Cr, Cu, Fe, K, P, Pb, Rb and Zn. The values of bioconcentration factor (BCF) varied highly depending on chemical element and were >1 for Ag, Cd, Cu, K, Mg, Na, P, Rb and Zn, while <1 for Al, Ba, Ca, Co, Cr, Fe, Mn, Ni, Pb and Sr. Topsoil showed elevated content of lead and mean concentration was 99 ± 32 μg/g dw, while cadmium was at 0.41 ± 0.15 and those two highly toxic to human elements occurred in edible caps of L. scabrum at 4.5 ± 2.2 and 2.9 ± 2.0 μg/g dw, respectively.     

Thermal history and large scale differentiation of the Saturn’s satellite Rhea

Thermal history of Rhea from the beginning of accretion is investigated. We developed a numerical model of convection combined with the parameterized theory. Large scale melting of the satellite’s matter and gravitational differentiation of silicates from ices are included. The results are confronted with observational data from Cassini spacecraft that indicate minor differentiation of the satellite’s interior. We suggest that partial differentiation of the satellite’s interior is accompanied (or followed) by the process of light fraction uprising to the surface. The calculation indicates that the partial differentiation of the matter of the satellite’s interior is possible only for narrow range of parameters. In particular, we found that the time from the formation of CAI (calciumaluminum rich inclusions in chondrites) to the end of accretion of Rhea is in the range of 3–4 My.     

Hydrodynamic Equilibrium for Sediment Transport and Bed Response to Wave Motion

An experimental and theoretical identification of hydrodynamic equilibrium for sediment transport and bed response to wave motion are considered. The comparison between calculations and the results of laboratory experiments indicates the linear relation between sediment transport rate and the thickness zm of bed layer in which sediments are in apparent rectilinear motion. This linear relationship allows to use the first order “upwind” numerical scheme of FDM ensuring an accurate solution of equation for changes in bed morphology. However, it is necessary to carry out a decomposition of the sediment transport into transport in onshore direction during wave crest and offshore direction during wave trough. Further, the shape of bed erosion in response to sediment transport coincides with the trapezoid envelope or with part of it, when some sediments still remain within it. Bed erosion area is equal to the one of a rectangle with thickness znm.     

Prospects for Scrutiny of Pulsars with Polish Part of LOFAR

LOFAR (LOw Frequency ARray) is a new generation digitally controlled radio telescope consisting of phased array antenna stations with sensitivity, bandwidth, range of frequency, and digital processing power that makes it an excellent tool for observations of pulsars. This interferometric instrument is able to work in a single-station mode as well as in group-of-selected-stations mode. This article discusses the great opportunity for conducting unique and independent research of pulsar sources with the three LOFAR stations located in Poland and maintained by the POLFAR consortium.     

Low-temperature zircon growth related to hydrothermal alteration of siderite concretions in Mississippian shales, Scotland

Zircon occurs in voids and cracks in phosphatic coprolites enclosed in siderite concretions in Mississippian shales near Edinburgh, Scotland. The zircon formed during hydrothermal alteration of early-diagenetic concretions and occurs as spherical aggregates of prismatic crystals, sometimes radiating. Vitrinite reflectance measurements indicate temperatures of ~270°C for the zircon-bearing concretions and the host shales. Molecular parameter values based on dibenzothiophene and phenanthrene distribution and occurrence of di- and tetra-hydro-products of polycyclic aromatic compounds suggest that the rocks experienced relatively high-temperature aqueous conditions related to hydrothermal fluids, perhaps associated with neighboring mafic intrusions. The zircon was dissolved from the concretions, transported in fluids, and reprecipitated in voids. This is the first record of the precipitation of authigenic zircon in sedimentary rock as a new phase, not as outgrowths.     

Reflection of the glacial-interglacial cycle in the evolution of the Vistula river Basin, Poland

A variety of factors has controlled the evolution of the Vistula river valley. They include climatically induced changes of the river runoff and sediment load, glacial advances and rapid variations of the base level, as well as the influence of the tectonic factor. The first-order climatic cycles are reflected in separate terrace fills. The second-order fluctuations may be represented by separate cuts and fills, by the change of the facies or by the change in the granulometric composition. The analysis of the changes in the longitudinal profile helped to discover a great variety of different valley reaches and a general tendency to smooth the long profile during the Quaternary.     

Organic geochemical evidences of early-diagenetic oxidation of the terrestrial organic matter during the Triassic arid and semi arid climatic conditions

The molecular character of organic matter (OM) present in Triassic clays of the Upper Silesia Basin and NW border of the Holy Cross Mountains was determined using GC–MS analysis. Oxidation processes were the major cause of the main changes of extractable OM molecular composition during sedimentation and early diagenesis of the Triassic clays. They resulted in a very significant decrease in the OM content of the clays and transformation of n-alkanes, triterpanes and steranes. Despite the changes in biomarker composition resulting from the disappearance of unsaturated and ββ hopanes and dominance of αβ and βα hopanes as well as preponderance of αββ over ααα steranes, the aromatic ketones were identified. Such PACs as benzophenone, fluorenone, cyclopenta(def)phenanthrenone, antracenone and benzanthrone were among the compounds identified in the red clays. These commonly originate during oxidation of sedimentary organic matter. Moreover, the aromatic fraction is characterized by the presence of phenyl derivatives (phenylnaphthalenes, terphenyls, phenyldibenzofurans and phenylphenanthrenes) that are also products of the abiotic oxidation of organic matter. Periods of terrestrial sedimentation have been interrupted by long phases of OM weathering and oxidation during arid conditions, and OM might only have survived without significant oxidation changes when the sedimentation was fast and/or long-lasting.     

Influence of the atmospheric conditions on PM<Subscript>10</Subscript> concentrations in Poznań, Poland

This study investigates atmospheric conditions’ influence on the mean and extreme characteristics of PM₁₀ concentrations in Poznań during the period 2006–2013. A correlation analysis was carried out to identify the most important meteorological variables influencing the seasonal dynamics of PM₁₀ concentrations. The highest absolute correlation values were obtained for planetary boundary layer height (r = ?0.57), thermal (daily minimum air temperature: r = ?0.51), anemological (average daily wind speed: r = ?0.37), and pluvial (precipitation occurrence: r = ?0.36) conditions, however the highest correlations were observed for temporal autocorrelations (1 day lag: r = 0.70). As regulated by law, extreme events were identified on the basis of daily threshold value i.e. 50 μg m^?3. On average, annually there are approximately 71.3 days anywhere in the city when the threshold value is exceeded, 46.6 % of those occur in winter. Additionally, 83.7 % of these cases have been found to be continuous episodes of a few days, with the longest one persisting for 22 days. The analysis of the macro-scale circulation patterns led to the identification of an easy-to-perceive seasonal relations between atmospheric fields that favour the occurrence of high PM₁₀ concentration, as well as synoptic situations contributing to the rapid air quality improvement. The highest PM₁₀ concentrations are a clear reaction to a decrease in air temperature by over 3 °C, with simultaneous lowering of PBL height, mean wind speed (by around 1 m s^?1) and changing dominant wind directions from western to eastern sectors. In most cases, such a situation is related to the expansion of a high pressure system over eastern Europe and weakening of the Icelandic Low. Usually, air quality conditions improve along with an intensification of westerlies associated with the occurrence of low pressure systems over western and central Europe. Opposite relations are distinguishable in summer, when air quality deterioration is related to the inflow of tropical air masses originating over the Sahara desert.