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

Bartosz Czernecki  Marek Półrolniczak  Leszek Kolendowicz  Michał Marosz  Sebastian Kendzierski  Natalia Pilguj 《Journal of Atmospheric Chemistry》2017,74(1):115-139

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.  相似文献   

Information infrastructure for Australia’s Integrated Marine Observing System     

Marton G. Hidas  Roger Proctor  Natalia Atkins  Julian Atkinson  Laurent Besnard  Peter Blain  Philip Bohm  Jon Burgess  Kim Finney  Dan Fruehauf  Guillaume Galibert  Xavier Hoenner  Jacqui Hope  Craig Jones  Sebastien Mancini  Benedicte Pasquer  David Nahodil  Kate Reid  Katherine Tattersall 《Earth Science Informatics》2016,9(4):525-534

Australia’s Integrated Marine Observing System (IMOS, imos.org.au) is research infrastructure to establish an enduring observing program for Australian oceanic waters and shelf seas. The observations cover physical, biological, and chemical variables to address themes of multi-decadal ocean change, climate variability and weather extremes, boundary currents and inter-basin flows, continental shelf processes and ecosystem responses.IMOS observations are collected by national facilities based on various platform types and operated by partner institutions around the country. In this paper we describe the infrastructure and workflows developed to manage and distribute the data to the public. We highlight the existing standards and open-source software we have adopted, and the contributions we have made. To demonstrate the value of this infrastructure we provide some illustrations of use and uptake.All IMOS data are freely and openly available to the public via the Ocean Portal (https://imos.aodn.org.au). All IMOS-developed software is open-source and accessible at https://github.com/aodn.  相似文献   

Evolution of the groundwater chemical composition in the Poyang Lake catchment,China     

Stepan Shvartsev  Zhaoli Shen  Zhanxue Sun  Guangcai Wang  Evgeniya Soldatova  Natalia Guseva 《Environmental Earth Sciences》2016,75(18):1239

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Polycyclic aromatic hydrocarbons in a small eastern siberian river: sources,delivery pathways,and behavior     

Mikhail Yu Semenov  Irina I. Marinaite  Nadezhda V. Bashenkhaeva  Natalia A. Zhuchenko  Olga I. Khuriganova  Elena V. Molozhnikova 《Environmental Earth Sciences》2016,75(11):954

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Geochemical mobility of arsenic in the surficial waters from Argentina     

Alicia Daniela Robles  Paula Polizzi  María Belén Romero  Leila Natalia Chiodi Boudet  Sandra Medici  Agustín Costas  Marcela Gerpe 《Environmental Earth Sciences》2016,75(23):1479

The presence of arsenic (As) in surface water constitutes an important environmental risk, where mobility and adsorption processes are responsible for its behavior in the sediment–water interface. Therefore, the assessment of adsorption, mobility and water availability of arsenic in freshwater sediments, with agricultural, livestock and urban soil uses was performed. Arsenic concentrations in sediments ranged from 5.4 to 15.9 mg kg^?1 (total) and 2.8 to 6.5 mg kg^?1 (labile), and those of iron and manganese were 11,563–23,500 and 140.6–662.1 mg kg^?1, respectively. The As levels in water were significantly lower than those of sediments. Results would suggest that As co-precipitation and adsorption on Fe oxides are probably the major route of immobilization, determining its low lability. Manganese did not present an outstanding contribution to the retention, and cation-exchange capacity, pH and organic matter of sediments did not show an influence on the mobility of As.  相似文献   

Seasonal and inter-annual dynamics of mesoplankton in the northwestern Japan Sea     

Natalia T. Dolganova  Yury I. Zuenko 《Progress in Oceanography》2004,61(2-4):227

Based upon four decades of observations in the northwestern part of the Japan Sea, the seasonal and inter-annual variations of zooplankton abundance and species composition in the epipelagic layer are considered. Seasonal characteristics of the zooplankton community are described in detail for five domains that occur within this part of the Japan Sea. Inter-decadal variation was not significant, but inter-annual variation was considerable and generally opposite to water temperature changes in the upper layer. Exceptional years such as 1996 were noted when a maximum abundance of zooplankton in summer occurred along with a slowing of the seasonal pattern of succession.  相似文献   

Mobilization of metals from riverine suspended matter in seawater   总被引：1，自引：0，他引：1  

Vladimir M. Shulkin  Natalia N. Bogdanova 《Marine Chemistry》2003,83(3-4):157

Suspended matter from rivers in the Russian Far East was leached by seawater to assess the extent of Zn, Cd, Pb, and Cu release from the land-derived solids to estuarine and coastal waters. The concentration of solids in the leaching experiments was 0.25 g/l. The suspended matter used varied in metal content from background levels to heavily contaminated.The concentration of Zn, Cd, Pb, and Cu in the leaching solution after 1, 4, 24, 48, and 96 h was determined by anodic stripping voltammetry. Measurable Cd was transferred from river suspended matter to seawater with both background and elevated Cd concentrations, though the amount of Cd released was different. The increase in Zn and Pb in solution was observed only at the enriched concentration of metals in the suspended solids. The Cu transfer into solution was more pronounced from material with elevated Cu concentration, but the amount of degradable organic matter in the solid phase was more important.The losses of metals from the riverine solids varied from 60% to 80% of total concentration for Cd to negligible for Pb, independent of contamination. The Zn loss depended on the initial concentration in the solids and decreased from 11–16% for the heavily contaminated suspended matter to 3–8% for the moderately enriched ones and to negligible for the pristine solids. Cu loss varied from 1% to 30% of total content, with no clear dependence on concentration in the suspended matter.The significance of additional input of dissolved metals to estuarine and coastal waters from remobilization was assessed by comparison with the initial concentration of dissolved metals in river water. Such experiments could be used to assess the water quality impact of atmospheric fallout of contaminated solids and storm drainage from the urbanized areas, in addition to river suspended matter studies.  相似文献   

Water exchange and water quality in the coastal zone in the presence of structures     

Izmail Kantardgi  Felix Mairanovsky  Natalia Sapova 《Coastal Engineering》1995,26(3-4)

The water exchange and water quality around coastal structures are considered by analytical, numerical and experimental methods. Water exchange for a small yacht harbour at the Black Sea coast is discussed as an application example. Physical and numerical experiments were carried out to determine the wave induced current field and to correlate the water exchange inside the area around the harbour mole. A hydraulic approach was applied to estimate the water exchange intensities for typical zones. The proposed mathematical model is an irregular wave-current model which includes the interaction between waves and current and a modified breaking criterion. The evolution of salinity concentration during the experimental investigations shows the water exchange intensity. A satisfactory agreement between calculated and measured concentration evolution was obtained.  相似文献   

On the echo interference in sound backscattering by densely aggregated targets     

Gorska  Natalia; Chu  Dezhang 《ICES Journal of Marine Science》2005,62(4):771-778

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Ejection of Martian meteorites     

Jrg Fritz  Natalia Artemieva  Ansgar Greshake 《Meteoritics & planetary science》2005,40(9-10):1393-1411

Abstract— We investigated the transfer of meteorites from Mars to Earth with a combined mineralogical and numerical approach. We used quantitative shock pressure barometry and thermodynamic calculations of post‐shock temperatures to constrain the pressure/temperature conditions for the ejection of Martian meteorites. The results show that shock pressures allowing the ejection of Martian meteorites range from 5 to 55 GPa, with corresponding post‐shock temperature elevations of 10 to about 1000 °C. With respect to shock pressures and post‐shock temperatures, an ejection of potentially viable organisms in Martian surface rocks seems possible. A calculation of the cooling time in space for the most highly shocked Martian meteorite Allan Hills (ALH) 77005 was performed and yielded a best‐fit for a post‐shock temperature of 1000 °C and a meteoroid size of 0.4 to 0.6 m. The final burial depths of the sub‐volcanic to volcanic Martian rocks as indicated by textures and mineral compositions of meteorites are in good agreement with the postulated size of the potential source region for Martian meteorites during the impact of a small projectile (200 m), as defined by numerical modeling (Artemieva and Ivanov 2004). A comparison of shock pressures and ejection and terrestrial ages indicates that, on average, highly shocked fragments reach Earth‐crossing orbits faster than weakly shocked fragments. If climatic changes on Mars have a significant influence on the atmospheric pressure, they could account for the increase of recorded ejection events of Martian meteorites in the last 5 Ma.  相似文献