TY  - JOUR
AU  - Sarvan, Darko
AU  - Stratimirović, Đorđe
AU  - Blesić, Suzana
AU  - Đurđević, Vladimir
AU  - Miljković, Vladimir
AU  - Ajtić, Jelena
PY  - 2017
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2198
AB  - The dynamics of the beryllium-7 specific activity in surface air over 1987-2011 is analyzed using wavelet transform (WT) analysis and time -dependent detrended moving average (tdDMA) method, WT analysis gives four periodicities in the beryllium-7 specific activity: one month, three months, one year, and three years. These intervals are further used in tdDMA to calculate local autocorrelation exponents for precipitation, tropopause height and teleconnection indices. Our results show that these parameters share common periods with the beryllium-7 surface concentration. tdDMA method indicates that on the characteristic intervals of one year and shorter, the beryllium-7 specific activity is strongly autocorrelated. On the three-year interval, the beryllium-7 specific activity shows periods of anticorrelat ion, implying slow changes in its dynamics that become evident only over a prolonged period of time. A comparison of the Hurst exponents of all the variables on the one- and three-year intervals suggest some similarities in their dynamics. Overall, a good agreement in the behavior of the teleconnection indices and specific activity of beryllium-7 in surface air is noted.
PB  - Elsevier, Amsterdam
T2  - Physica A-Statistical Mechanics & its Applications
T1  - Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number
VL  - 469
SP  - 813
EP  - 823
DO  - 10.1016/j.physa.2016.11.040
ER  - 

@article{
author = "Sarvan, Darko and Stratimirović, Đorđe and Blesić, Suzana and Đurđević, Vladimir and Miljković, Vladimir and Ajtić, Jelena",
year = "2017",
abstract = "The dynamics of the beryllium-7 specific activity in surface air over 1987-2011 is analyzed using wavelet transform (WT) analysis and time -dependent detrended moving average (tdDMA) method, WT analysis gives four periodicities in the beryllium-7 specific activity: one month, three months, one year, and three years. These intervals are further used in tdDMA to calculate local autocorrelation exponents for precipitation, tropopause height and teleconnection indices. Our results show that these parameters share common periods with the beryllium-7 surface concentration. tdDMA method indicates that on the characteristic intervals of one year and shorter, the beryllium-7 specific activity is strongly autocorrelated. On the three-year interval, the beryllium-7 specific activity shows periods of anticorrelat ion, implying slow changes in its dynamics that become evident only over a prolonged period of time. A comparison of the Hurst exponents of all the variables on the one- and three-year intervals suggest some similarities in their dynamics. Overall, a good agreement in the behavior of the teleconnection indices and specific activity of beryllium-7 in surface air is noted.",
publisher = "Elsevier, Amsterdam",
journal = "Physica A-Statistical Mechanics & its Applications",
title = "Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number",
volume = "469",
pages = "813-823",
doi = "10.1016/j.physa.2016.11.040"
}

Sarvan, D., Stratimirović, Đ., Blesić, S., Đurđević, V., Miljković, V.,& Ajtić, J.. (2017). Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number. in Physica A-Statistical Mechanics & its Applications
Elsevier, Amsterdam., 469, 813-823.
https://doi.org/10.1016/j.physa.2016.11.040

Sarvan D, Stratimirović Đ, Blesić S, Đurđević V, Miljković V, Ajtić J. Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number. in Physica A-Statistical Mechanics & its Applications. 2017;469:813-823.
doi:10.1016/j.physa.2016.11.040 .

Sarvan, Darko, Stratimirović, Đorđe, Blesić, Suzana, Đurđević, Vladimir, Miljković, Vladimir, Ajtić, Jelena, "Dynamics of beryllium-7 specific activity in relation to meteorological variables, tropopause height, teleconnection indices and sunspot number" in Physica A-Statistical Mechanics & its Applications, 469 (2017):813-823,
https://doi.org/10.1016/j.physa.2016.11.040 . .

TY  - CONF
AU  - Ajtić, Jelena
AU  - Maletić, Dimitrije
AU  - Stratimirović, Đorđe
AU  - Blesić, Suzana
AU  - Nikolić, Jelena
AU  - Đurđević, Vladimir
AU  - Todorović, Dragana
PY  - 2015
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/2056
AB  - Dependence of the lead-210 activity concentration in surface air on meteorological variables and teleconnection indices is investigated using multivariate analysis, which gives the Boosted Decision Trees method as the most suitable for variable analysis. A mapped functional behaviour of the lead-210 activity concentration is further obtained, and used to test predictability of lead-210 in surface air. The results show an agreement between the predicted and measured values. The temporal evolution of the measured activities is satisfactorily matched by the prediction. The largest qualitative differences are obtained for winter months.
PB  - RAD Association
C3  - RAD Conference Proceedings
T1  - Predictability of lead-210 in surface air based on multivariate analysis
VL  - 2015-June
SP  - 317
EP  - 322
UR  - https://hdl.handle.net/21.15107/rcub_vinar_7129
ER  - 

@conference{
author = "Ajtić, Jelena and Maletić, Dimitrije and Stratimirović, Đorđe and Blesić, Suzana and Nikolić, Jelena and Đurđević, Vladimir and Todorović, Dragana",
year = "2015",
abstract = "Dependence of the lead-210 activity concentration in surface air on meteorological variables and teleconnection indices is investigated using multivariate analysis, which gives the Boosted Decision Trees method as the most suitable for variable analysis. A mapped functional behaviour of the lead-210 activity concentration is further obtained, and used to test predictability of lead-210 in surface air. The results show an agreement between the predicted and measured values. The temporal evolution of the measured activities is satisfactorily matched by the prediction. The largest qualitative differences are obtained for winter months.",
publisher = "RAD Association",
journal = "RAD Conference Proceedings",
title = "Predictability of lead-210 in surface air based on multivariate analysis",
volume = "2015-June",
pages = "317-322",
url = "https://hdl.handle.net/21.15107/rcub_vinar_7129"
}

Ajtić, J., Maletić, D., Stratimirović, Đ., Blesić, S., Nikolić, J., Đurđević, V.,& Todorović, D.. (2015). Predictability of lead-210 in surface air based on multivariate analysis. in RAD Conference Proceedings
RAD Association., 2015-June, 317-322.
https://hdl.handle.net/21.15107/rcub_vinar_7129

Ajtić J, Maletić D, Stratimirović Đ, Blesić S, Nikolić J, Đurđević V, Todorović D. Predictability of lead-210 in surface air based on multivariate analysis. in RAD Conference Proceedings. 2015;2015-June:317-322.
https://hdl.handle.net/21.15107/rcub_vinar_7129 .

Ajtić, Jelena, Maletić, Dimitrije, Stratimirović, Đorđe, Blesić, Suzana, Nikolić, Jelena, Đurđević, Vladimir, Todorović, Dragana, "Predictability of lead-210 in surface air based on multivariate analysis" in RAD Conference Proceedings, 2015-June (2015):317-322,
https://hdl.handle.net/21.15107/rcub_vinar_7129 .

TY  - CONF
AU  - Ajtić, Jelena
AU  - Stratimirović, Đorđe
AU  - Đurđević, Vladimir
AU  - Todorović, D.
AU  - Nikolić, J.
PY  - 2014
UR  - https://smile.stomf.bg.ac.rs/handle/123456789/1934
AB  - Activities of beryllium-7 and lead-210 are monitored in ground level air in Belgrade, Serbia. The measuring sites are located at the Institute of Nuclear Sciences Vinča. The activities are determined on HPGe detectors by standard gamma spectrometry. Five teleconnection indices of large scale atmospheric circulation: North Atlantic Oscillation, East Atlantic Pattern, East Atlantic/West Russia Pattern, Scandinavia Pattern, and Polar/Eurasia Pattern are obtained from the data archive of the United States National Oceanic and Atmospheric Administration's Climate Prediction Center. The collected time series consist of monthly values and span more than two decades: beryllium-7 since 1991, lead-210 since 1985, and the teleconnection indices since 1950, thus offering data arrays of sufficient lengths for wavelet spectral analysis. A relation between the radionuclides' activities and the indices is first investigated using Pearson's correlation coefficients. The computed coefficients do not indicate a linear relationship between the variables. However, the wavelet spectral analysis shows a number of common characteristic frequencies in the data arrays. The annual cycle of all the variables is clearly evident. A common time period of two to three years is also found, as well as a higher frequency variability corresponding to five to six months.
PB  - RAD Association
C3  - RAD Conference Proceedings
T1  - Wavelet spectral analysis of teleconnection indices and activities of beryllium-7 and lead-210 in ground level air in Belgrade, Serbia
VL  - 2014-May
SP  - 53
EP  - 56
UR  - https://hdl.handle.net/21.15107/rcub_veterinar_1130
ER  - 

@conference{
author = "Ajtić, Jelena and Stratimirović, Đorđe and Đurđević, Vladimir and Todorović, D. and Nikolić, J.",
year = "2014",
abstract = "Activities of beryllium-7 and lead-210 are monitored in ground level air in Belgrade, Serbia. The measuring sites are located at the Institute of Nuclear Sciences Vinča. The activities are determined on HPGe detectors by standard gamma spectrometry. Five teleconnection indices of large scale atmospheric circulation: North Atlantic Oscillation, East Atlantic Pattern, East Atlantic/West Russia Pattern, Scandinavia Pattern, and Polar/Eurasia Pattern are obtained from the data archive of the United States National Oceanic and Atmospheric Administration's Climate Prediction Center. The collected time series consist of monthly values and span more than two decades: beryllium-7 since 1991, lead-210 since 1985, and the teleconnection indices since 1950, thus offering data arrays of sufficient lengths for wavelet spectral analysis. A relation between the radionuclides' activities and the indices is first investigated using Pearson's correlation coefficients. The computed coefficients do not indicate a linear relationship between the variables. However, the wavelet spectral analysis shows a number of common characteristic frequencies in the data arrays. The annual cycle of all the variables is clearly evident. A common time period of two to three years is also found, as well as a higher frequency variability corresponding to five to six months.",
publisher = "RAD Association",
journal = "RAD Conference Proceedings",
title = "Wavelet spectral analysis of teleconnection indices and activities of beryllium-7 and lead-210 in ground level air in Belgrade, Serbia",
volume = "2014-May",
pages = "53-56",
url = "https://hdl.handle.net/21.15107/rcub_veterinar_1130"
}

Ajtić, J., Stratimirović, Đ., Đurđević, V., Todorović, D.,& Nikolić, J.. (2014). Wavelet spectral analysis of teleconnection indices and activities of beryllium-7 and lead-210 in ground level air in Belgrade, Serbia. in RAD Conference Proceedings
RAD Association., 2014-May, 53-56.
https://hdl.handle.net/21.15107/rcub_veterinar_1130

Ajtić J, Stratimirović Đ, Đurđević V, Todorović D, Nikolić J. Wavelet spectral analysis of teleconnection indices and activities of beryllium-7 and lead-210 in ground level air in Belgrade, Serbia. in RAD Conference Proceedings. 2014;2014-May:53-56.
https://hdl.handle.net/21.15107/rcub_veterinar_1130 .

Ajtić, Jelena, Stratimirović, Đorđe, Đurđević, Vladimir, Todorović, D., Nikolić, J., "Wavelet spectral analysis of teleconnection indices and activities of beryllium-7 and lead-210 in ground level air in Belgrade, Serbia" in RAD Conference Proceedings, 2014-May (2014):53-56,
https://hdl.handle.net/21.15107/rcub_veterinar_1130 .