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Search Results: 1 - 10 of 287 matches for " Duci? Vladan "
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Dynamics of ozone layer under Serbia and solar activity: Previous statement
DuciVladan,Nikoli? Jugoslav
Glasnik Srpskog Geografskog Dru?tva , 2008, DOI: 10.2298/gsgd0801070d
Abstract: The aim of this paper is to identify ozone layer dynamics under Serbian area, as well as possible relations of change in stratospheric ozone concentration with some parameters of solar activity. During the period 1979-2005, the statistical decrease of ozone concentration was noticed under Serbian territory cumulatively for 24.5 DU (7.2%), apropos 9.4 DU (2.8%) by decade. These changes are consistent with the changes in surrounding countries. From absolute minimum 1993, flexible trend of ozone layer pentad values validate hypotheses of its recovery. Correspondence of ozone thickness extreme period with Wolf's number and with the greatest volcanic eruptions shows that interannual variations of stratospheric ozone concentration are still in the function of natural factors above all, as are solar and volcanic activities. Investigation of larger number solar activity parameters shows statistically important antiphase synchronous between the number of polar faculae on the Sun and stratospheric ozone dynamics under Serbia. Respecting that relation between these two features until now isn't depicted, some possible causal mechanisms are proposed.
Possible causes of contemporary Nisava River discharge variability
DuciVladan,Lukovi? Jelena
Glasnik Srpskog Geografskog Dru?tva , 2009, DOI: 10.2298/gsgd0904255d
Abstract: Nisava River is the largest tributary of the South Morava River of length 248 km, of which 151 km is in Serbia. Annually to all three hydrological profiles (Pirot, Bela Palanka and Nis) in the reporting period (1961-2000) has been observed decrease in discharge. That would be in accordance with the IPCC's claims about the domination of the influence of anthropogenic greenhouse gases on the reduction of rainfall and discharge in Serbia. However, the area of the Nisava basin in the second half of the XX century has shown decrease in air temperature. The station Dimitrovgrad, in the upper part of the basin, from 1949 to 2007 showed trend of annual temperature of -0.0049oC per year, which does not fit to the concept of dominance of anthropogenic greenhouse gases. And the trend of rainfall in this period, changes sign from negative to positive (0.1175mm per year), so that it does not fit the concept of domination of the global anthropogenic impact on regional models of IPCC. Regarding to this and projections of possible climate change in the future all potential climatic factors should be taking into account.
Temperature variability on the area of Stara planlna in the instrumental period
DuciVladan,Radovanovi? Milan,Milovanovi? Bo?ko
Glasnik Srpskog Geografskog Dru?tva , 2005, DOI: 10.2298/gsgd0502023d
Abstract: In this paper are presented the results of research, considering on air temperature variability in Stara planina area. In southeast part of researched area it is noticed negative trend in the last 50 years of XX century, according to data of IPCC for Southeast Europe. Emphasized air temperature increase in summer period in almost stations is not pointed on dominant influence of anthropogenic greenhouse effect.
Possible connection between Danube river discharge variability and solar activity
DuciVladan,Lukovi? Jelena,Nikolova Nina
Glasnik Srpskog Geografskog Dru?tva , 2007, DOI: 10.2298/gsgd0701031d
Abstract: Relations between discharge changes and solar activity are very complex and this is the reason why the obtained results are often contradictory. In this paper we tray to explore possible relation between Danube river discharge elements and parameters of solar activity. The best result has been found between flow index and latitude of sunspots. According to literature we propose possible mechanism of solar activity influence on the discharge.
Changes of Danube discharge parameters at Or ava hydrological station: In the period 1841-2000
DuciVladan,Nikoli? Jugoslav,Dragi?evi? Slavoljub
Glasnik Srpskog Geografskog Dru?tva , 2006, DOI: 10.2298/gsgd0601035d
Abstract: The aim of this research was to determine long-term trend of discharge, over its different parameters. Hydrological station Or ava is selected not just because of series’ length but also reliabilities of observation. By analyzing data, we exclude possible local and regional anthropogenic influences on discharge. Trend analyzes of all parameters of the Danube discharge near Or ava hydrological station in the period of 160 years show increase of discharge and decrease of extremeness.
The analysis of precipitation conducted on the upper watershed of the West Morava river
Nikoli? Jugoslav,DuciVladan,Dragi?evi? Slavoljub
Glasnik Srpskog Geografskog Dru?tva , 2005, DOI: 10.2298/gsgd0501019n
Abstract: Precipitation is one of the basic elements of the water balance and its analysis is of the crucial importance for many scientific areas. The analysis of precipitation, conducted on the upper part watershed of the West Morava River, was done in the complex way, with the use of the appropriate numerical model. In this way, among other things, orographic and dynamic effects on the explored terrain are taken into consideration.
A condition and dynamics of the earth's ozone layer with attention on the Montreal protocol
DuciVladan,?ur?i? Sne?ana
Glasnik Srpskog Geografskog Dru?tva , 2005, DOI: 10.2298/gsgd0501049d
Abstract: The paper presents the analyses of the condition and dynamics of earth's ozone layer on the base of the latest satellite measurements and estimated results of the pollutants emissions. On the basis of those results it presented an attempt of explanation of the ozone layer dynamics by prospective causality. Furthermore, paper work contents analyses of activities and measures that are provided by international document known as Montreal Protocol on Substances that Deplete the Ozone Layer.
Ocean and atmosphere coupling, connection between sub-polar Atlantic air temperature, Icelandic minimum and temperature in Serbia
Milovanovi? Bo?ko,Radovanovi? Milan,DuciVladan
Glasnik Srpskog Geografskog Dru?tva , 2009, DOI: 10.2298/gsgd0903165m
Abstract: In the presented paper correlation between the northern part of the Atlantic ocean (belt between 50-65°N) and the atmospheric pressure is examined. Connection between the ocean temperature and atmospheric pressure is the most obvious in the El Nino southern oscillation mechanism. Thus, so far it is not known that such a mechanism exist in the Atlantic ocean. The main accent in the presented paper is focused on the connection between Iceland low and the sea surface temperature (SST) in the subpolar part of the Atlantic ocean (used data are in grid 5x5°). By hierarchical cluster analysis five relatively unified clusters of sea surface temperatures grid cells are defined. By multiple linear regression, we examined the correlation between each of the depicted clusters with position and intensity of Iceland low, and identified the most important grid cells inside every cluster. The analysis of the relation between Iceland low and air temperature in Serbia and Belgrade has shown the strongest correlation for the longitude of this centre of action. .
Atmospheric circulation and the precipitation variability in Serbia for period 1949-2004
DuciVladan,Lukovi? Jelena,Stanojevi? Gorica
Glasnik Srpskog Geografskog Dru?tva , 2010, DOI: 10.2298/gsgd1002085d
Abstract: In this paper we have analyzed the correlation between the atmospheric circulation and annual precipitation in Serbia for period 1949-2004. The data for frequency Hess-Brezowsky circulation forms and types were used as indicators of atmospheric circulation. Statistically significant coefficient of a negative sign is obtained for zonal and half-meridional form and a positive sign for meridional form. The strength of correlation is not uniform in the space. According to the multiple linear regression the contribution of atmospheric circulation in the variability annual precipitation of Serbia is 69%. Also, we analyzed the connection between the atmospheric circulation and the mean annual cloudiness. Comparing the results for this two climate elements we have concluded that they show different time-space development for same macrosynoptic conditions. Also, we can speak about the regional aspects of these processes. .
Temperature variability in Serbia in the second half of the 20th century
Radovanovi? Milan M.,DuciVladan D.
Glasnik Srpskog Geografskog Dru?tva , 2004, DOI: 10.2298/gsgd0401019r
Abstract: According to data of IPCC (Intergovernmental Panel for Climatic Change), the global surface air temperature increased to 0,6 ± 0,2 °C in the 20th century. Weber G. R., (1995) quotes that there is a trend of cold in the last 60 years in the middle latitudes including Europe, too. Starting from already mentioned perplexities we have tried to perceive the problem of climate variability in Serbia in the second half of the 20th century, when it came to very important increasing of concentration of CO2. With that aim we observed the decade values of average annual temperatures in the network of 20 climatic stations. In the period 1951 - 1990 a decrease of temperature was registered in 13 stations while in other stations an increase was less than 0,1 °C. Explorers from Bulgaria (Alexandrov V., 2000) and Hungary (Domonkos P., Zoboki J., 2000) came to similar results, too. However, if we take in account the last decade 20th century the number of stations with positive changes is enlarged on 15. Stations that have small changes and those with decrease of temperature were localized in the south and south eastern part of the country, and they are mainly coincided with before separated climatic regions with maritime pluviometric regime (Radovanovi M., 2001). Using Dzerdzevskis B. L., (1975) division on three main types of circulation in the north hemisphere, we found that the increase of temperatures in the last decade 20th century is above all caused by change of dominant type of circulation from the south meridian to zonal. An analysis of seasonal changes showed that in the last five decades 20th century it came to decrease of winter temperatures in almost half of the stations in contrast with results of paleoclimatics models of possible greenhouse effect.
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