Aridity in Vojvodina, Serbia   总被引：2，自引：1，他引：1  

Ivana Hrnjak  Tin Lukić  Milivoj B. Gavrilov  Slobodan B. Marković  Miroslava Unkašević  Ivana Tošić 《Theoretical and Applied Climatology》2014,115(1-2):323-332

For investigating aridity in Vojvodina, two parameters were used: the De Martonne aridity index and the Pinna combinative index. These indices were chosen as the most suitable for the analysis of climate in Vojvodina (a region in northern part of Serbia). Also, these indices were calculated from data obtained from 10 meteorological stations for the period from 1949 to 2006. The spatial distribution of the annual and seasonal De Martonne and the Pinna combinative indices as well as the mean monthly values of the De Martonne index and aridity trends of these indices are presented. There were two, four, and five types of climate on a yearly, seasonal, and monthly basis in Vojvodina, according to the De Martonne climate classification which consists of a total of seven types. In addition, semi-humid and humid climate types were represented in the region, on a yearly basis. The winter season was dominated by wetter types of climate, while the summer season was characterized by drier ones. During the spring and autumn seasons, there were types of climate which range between both aforementioned types. Two out of three climate types, which can be identified using the Pinna combinative index, were registered in Vojvodina region. The most dominant climate type was the semidry Mediterranean with formal Mediterranean vegetation, while the humid type was only identified in one small part of southwestern Vojvodina. The calculated values of both aridity indices showed that there were no annual trends. Therefore, it can be considered that there were no recent aridity changes during the observed period. For paleoclimate, the general story is more complex. The lack of aridity trends in the recent period from 1949 to 2006 supports the fact that Vojvodina has very well preserved loess–palaeosol sequences from the Middle and Late Pleistocene, which indicates that crucial point for their preservation was caused by the weak aridity variability in the region.  相似文献   

Multiple Regression Analysis as Indicator of Hazardous Organic Pollutants Interdependency in Pad Press Indoor Air          下载免费PDF全文

Jelena S. Kiurski  Snezana M. Aksentijevic  Ivana B. Oros  Vesna S. Kecic  Ilija B. Kovacevic 《洁净——土壤、空气、水》2016,44(12):1605-1613

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The temporal variation of indoor pollutants in photocopying shop     

Jelena S. Kiurski  Ivana B. Oros  Vesna S. Kecic  Ilija M. Kovacevic  Snezana M. Aksentijevic 《Stochastic Environmental Research and Risk Assessment (SERRA)》2016,30(4):1289-1300

The paper includes the identification of the main factors responsible for the temporal variations of indoor pollutants during three daily intervals in a photocopying shop. The measurements of concentration levels of total volatile organic compounds, ozone, carbon monoxide, carbon dioxide, nitrogen dioxide, ammonia, perchloroethylene and non-methane hydrocarbons were performed. The individual concentrations of target pollutants were subjected to principal component analysis (PCA) using a software XLSTAT 2014.1.10. Pearson correlation model indicated the relatively weak correlation between the investigated pollutants in a photocopying environment. PCA extracted three principal components (PCs) from the indoor air pollution data set. Obtained PCs explained 56.72 % of the total variance. The summarized biplots showed which pollutants are responsible for photocopying indoor pollution per sampling day/sampling point/time interval/number of measurement. The results pointed out that the main PCs were related to the usage of toners, electrostatic discharge, heating of photocopiers as well as general intensifying of photocopying processes.  相似文献   

Downdraft effects in a shallow convection adjustment     

Ivana Nemešová 《Studia Geophysica et Geodaetica》1991,35(3):244-249

Summary The paper deals with the role of penetrative downdrafts in the convective adjustment suggested by Betts[1]. Three different types of downdraft sinking levels are used in the assessment of the reference profiles of temperature and humidity in cumulus cloud layers and these are compared with the profiles with no downdraft. It is shown that the depths of downdraft penetration may significantly influence the reference profiles mainly for clouds of vertical extents larger than one kilometre.  相似文献   

A steady-state model of a cumulus cloud     

Ivana Nemešová  Reviewer O. Zikmunda 《Studia Geophysica et Geodaetica》1979,23(4):368-380

nua u mam n ma aa ¶rt;mn ¶rt;u aa, ma a n¶rt;a [1]. mma m ¶rt;u aa a ¶rt;auu nauMi (uuuu n) uMa (¶rt;uauu anm), m amm u nu [2–5]. u¶rt;m mam u nu ¶rt;u ¶rt; u¶rt; mu ¶rt; u a ¶rt; ¶rt;a. mu a aa, n¶rt;ua m a aa, nua a¶rt; u u _i uu a a¶rt; z_i nu nu aa ¶rt; ¶rt;a, m ¶rt;um mua m, a¶rt;u ¶rt; a, ¶rt;m, mnam, anu ¶rt; naa, nm a an u nu. a ¶rt;mn ¶rt;u m n a nu u ¶rt;mn ¶rt;u, ma a ma n¶rt;a [1].  相似文献   

Application of the restrictedD-optimal design to gravimetry     

Ludmila Kubáčková  Ivana Jakubcová  Miloš Pick  Stanislav Hrách  Reviewer J. Anděl  Reviewer Z. Šimon 《Studia Geophysica et Geodaetica》1979,23(1):10-16

Summary The theory of the restricted D-optimal design was used for the project of gravity measurements in a pressure chamber. An example of the measurements is presented.  相似文献   

A note on the effect of the ground on the convective temperature field in the atmospheric surface layer     

Ivana Nemešová  Reviewer S. Brandejs 《Studia Geophysica et Geodaetica》1973,17(1):68-71

Summary The paper presents the solution of the equation of heat conduction with density of heat sources given generally. For two special cases the computed central temperature excesses of model[5] are compared with the results of some authors[1, 6] who deal with convection in the surface layer.  相似文献   

Quality factor inversion determination from the analysis of body wave data     

R. Sato  A. F. Espinosa 《Pure and Applied Geophysics》1967,67(1):15-26

Summary In this investigation, a method is developed which allows the determination of the distribution of the intrinsic attenuation with depth in the earth's mantle using single body wave observations. Focal mechanism, geometrical spreading and the source function are not involved in the proposed method. Several examples are presented obeying different laws of the quality factor decreasing or increasing with depth. A case is shown where a first order discontinuity is present, and also when the hypocenter varies with depth.  相似文献   

Tectonic rotations during the Chile Ridge collision and obduction of the Taitao ophiolite (southern Chile)   总被引：2，自引：0，他引：2  

Eugenio Andrés  Espinosa Veloso  Ryo  Anma  Toshitsugu  Yamazaki 《Island Arc》2005,14(4):599-615

Abstract The < 6 Ma young Taitao ophiolite, exposed at the westernmost promontory of the Taitao Peninsula, is located approximately 40 km southeast of the Chile triple junction and consists of a complete sequence of oceanic lithosphere. Systematic sampling for paleomagnetic study was performed to understand the complex obduction processes of the ophiolite onto the forearc of the South American Plate. Two representative demagnetization paths of remanent magnetization vectors were observed. One is characterized by stable univectorial demagnetization paths and was observed in volcaniclastic rocks and dyke complexes. Orientations of their remanent magnetization vectors indicate various degrees of counterclockwise rotations. The other is characterized by multivectorial demagnetization paths and was observed in the plutonic units (gabbros and ultramafic rocks). From these, two distinct stable remanent magnetization vectors were isolated; one has high coercivity and the other has low coercivity along the demagnetization paths with little influence of viscous magnetizations. This suggests that the complex deformation history involved at least two rotational events. The clockwise rotation, inferred from high coercivity remanent magnetization vectors, was attributed to a ridge collision event and the counterclockwise rotation, inferred from the low coercivity remanent magnetization vectors, was attributed to an accommodation phase into the South American forearc during obduction and final emplacement of the ophiolite. Folds developed during this period. Paleomagnetic restorations of the internal structures of the plutonic units and dyke complexes suggest that they probably originated in a mid‐oceanic ridge environment near a transform fault. The counterclockwise rotation of the plutonic and dyke complex units during the obduction generated tectonic gaps between these and the basement. The volcaniclastic rocks must have been deposited at nearly their present location, filling the tectonic gaps, as less effect of tectonic rotation was identified on these rocks.  相似文献   

Modern Diatom Assemblages in Surface Sediments from Estuarine Systemsin the Southeastern Buenos Aires Province, Argentina   总被引：1，自引：0，他引：1  

Gabriela S. Hassan  Marcela A. Espinosa  Federico I. Isla 《Journal of Paleolimnology》2006,35(1):39-53

Paleoecological reconstructions of Holocene sea-level changes in Argentinean coastal regions were based mainly on ecological data gathered from other regions, as there was a lack of information on modern estuarine diatom distributions. The aim of the present work was to assess the spatial variation of diatom assemblages in two representative estuaries of Argentina in order to gather ecological information for paleoecological reconstructions in the region. The two selected estuaries have different geomorphologic features and salinity regimes: Mar Chiquita Lagoon is shallow, which prevents the development of a stable salinity gradient as it occurs in the Quequén Grande River. Surface sediment samples were taken from selected stations representative of the environmental gradient from the inlet to the inner reaches of both estuaries. Cluster analysis defined three diatom zones at Mar Chiquita: marine/brackish assemblages dominate the inlet (zone I), where salinity, tidal range and current speed are higher. The brackish/freshwater tychoplankton Staurosira construens var. venter and Staurosirella pinnata dominate the inner lagoon (zone II), where environmental conditions are very variable and concentrations of suspended sediments are higher. Brackish/freshwater euryhaline diatoms dominate the headwaters (zone III). On the other hand, the Quequén Grande River was divided into three diatom zones: coastal taxa are distributed at the inlet (zone I), while the middle estuary (zone II) is dominated by brackish/freshwater euryhaline taxa. At the upper estuary region (zone III), freshwater diatoms dominate, and the halophobous Nitzschia denticula increased in abundance values. Diatom distributions were most closely related to the salinity gradient at Quequén Grande River than at Mar Chiquita Lagoon. Fossil data of a sequence from Mar Chiquita Lagoon (Las Gallinas Creek) were compared to the modern data set in order to search for analogies between fossil and modern diatom assemblages. DCA results showed that fossil diatom assemblages have modern counterparts. Most diatom assemblages of Las Gallinas Creek fall within Mar Chiquita zone III, representing a shallow brackish/freshwater environment, with low salinity fluctuations (~1–9‰) and no tidal influence. Therefore, our modern diatom data provide useful analogs to interpret paleoenvironments in the region.  相似文献