TY  - CONF
AU  - Bianchi, Stefano
AU  - Plastino, Wolfango
AU  - Rajačić, Milica
AU  - Krneta Nikolić, Jelena
AU  - Todorović, Dragana
AU  - Zorko, Benjamin
AU  - Nečemer, Marijan
AU  - Vodenik, Branko
AU  - Glavič Cindro, Denis
AU  - Kožar Logar, Jasmina
AU  - Sarvan, Darko
AU  - Đurđević, Vladimir
AU  - Ajtić, Jelena
PY  - 2022
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/2479
AB  - Beryllium-7 is a natural radionuclide used as a tracer of the stratospheric-tropospheric exchange. Its abundance in the surface air is expected to change as the temperatures in the atmosphere increase.
To investigate the temporal trends of the beryllium-7 activity concentrations and temperature, we apply spectral analysis to time series from three sampling sites: Belgrade in Serbia, and Ljubljana and Krško in Slovenia. The sites lie close to the 45 ºN parallel, with Krško approximately 400 km and Ljubljana around 500 km west of Belgrade. Between January 1991 and December 2019, the air filter samples were collected using air samplers; a monthly composite sample was formed and analysed by gamma spectrometry. We use monthly mean temperature records from the European Climate Assessment & Dataset, the Republic Hydrometeorological Service of Serbia for Belgrade, and the Slovenian Environment Agency for the sites in Slovenia.
In the spectral analysis decomposition, we look into a term called trend that represents the overall growth (increase or decrease) in the data records. The trend is calculated using a linear fit. All three sites show 1) positive temperature trends, however statistically insignificant (at the 95 % confidence level), and 2) statistically significant beryllium-7 activity concentration trends of 2.26 %/year, 1.13 %/year, and 0.50 %/year in Belgrade, Ljubljana, and Krško, respectively.
The results confirm our initial hypothesis–over the 28 investigated years, the beryllium-7 activity concentrations increase in the surface air. On the other hand, the non-significant temperature rise in our records suggests that within our method, the temporal resolution of one month is insufficient for obtaining a statistically significant temperature trend.
PB  - Niš : Sievert Association
C3  - International conference on radiation applications (RAP 2022)
T1  - Beryllium-7 activity concentration trends in Serbia and Slovenia
SP  - 45
UR  - https://hdl.handle.net/21.15107/rcub_veterinar_2479
ER  - 

@conference{
author = "Bianchi, Stefano and Plastino, Wolfango and Rajačić, Milica and Krneta Nikolić, Jelena and Todorović, Dragana and Zorko, Benjamin and Nečemer, Marijan and Vodenik, Branko and Glavič Cindro, Denis and Kožar Logar, Jasmina and Sarvan, Darko and Đurđević, Vladimir and Ajtić, Jelena",
year = "2022",
abstract = "Beryllium-7 is a natural radionuclide used as a tracer of the stratospheric-tropospheric exchange. Its abundance in the surface air is expected to change as the temperatures in the atmosphere increase.
To investigate the temporal trends of the beryllium-7 activity concentrations and temperature, we apply spectral analysis to time series from three sampling sites: Belgrade in Serbia, and Ljubljana and Krško in Slovenia. The sites lie close to the 45 ºN parallel, with Krško approximately 400 km and Ljubljana around 500 km west of Belgrade. Between January 1991 and December 2019, the air filter samples were collected using air samplers; a monthly composite sample was formed and analysed by gamma spectrometry. We use monthly mean temperature records from the European Climate Assessment & Dataset, the Republic Hydrometeorological Service of Serbia for Belgrade, and the Slovenian Environment Agency for the sites in Slovenia.
In the spectral analysis decomposition, we look into a term called trend that represents the overall growth (increase or decrease) in the data records. The trend is calculated using a linear fit. All three sites show 1) positive temperature trends, however statistically insignificant (at the 95 % confidence level), and 2) statistically significant beryllium-7 activity concentration trends of 2.26 %/year, 1.13 %/year, and 0.50 %/year in Belgrade, Ljubljana, and Krško, respectively.
The results confirm our initial hypothesis–over the 28 investigated years, the beryllium-7 activity concentrations increase in the surface air. On the other hand, the non-significant temperature rise in our records suggests that within our method, the temporal resolution of one month is insufficient for obtaining a statistically significant temperature trend.",
publisher = "Niš : Sievert Association",
journal = "International conference on radiation applications (RAP 2022)",
title = "Beryllium-7 activity concentration trends in Serbia and Slovenia",
pages = "45",
url = "https://hdl.handle.net/21.15107/rcub_veterinar_2479"
}

Bianchi, S., Plastino, W., Rajačić, M., Krneta Nikolić, J., Todorović, D., Zorko, B., Nečemer, M., Vodenik, B., Glavič Cindro, D., Kožar Logar, J., Sarvan, D., Đurđević, V.,& Ajtić, J.. (2022). Beryllium-7 activity concentration trends in Serbia and Slovenia. in International conference on radiation applications (RAP 2022)
Niš : Sievert Association., 45.
https://hdl.handle.net/21.15107/rcub_veterinar_2479

Bianchi S, Plastino W, Rajačić M, Krneta Nikolić J, Todorović D, Zorko B, Nečemer M, Vodenik B, Glavič Cindro D, Kožar Logar J, Sarvan D, Đurđević V, Ajtić J. Beryllium-7 activity concentration trends in Serbia and Slovenia. in International conference on radiation applications (RAP 2022). 2022;:45.
https://hdl.handle.net/21.15107/rcub_veterinar_2479 .

Bianchi, Stefano, Plastino, Wolfango, Rajačić, Milica, Krneta Nikolić, Jelena, Todorović, Dragana, Zorko, Benjamin, Nečemer, Marijan, Vodenik, Branko, Glavič Cindro, Denis, Kožar Logar, Jasmina, Sarvan, Darko, Đurđević, Vladimir, Ajtić, Jelena, "Beryllium-7 activity concentration trends in Serbia and Slovenia" in International conference on radiation applications (RAP 2022) (2022):45,
https://hdl.handle.net/21.15107/rcub_veterinar_2479 .

TY  - JOUR
AU  - Bianchi, Stefano
AU  - Plastino, Wolfango
AU  - Brattich, Erika
AU  - Đurđević, Vladimir
AU  - Longo, Alessandro
AU  - Hernandez-Ceballos, Miguel A.
AU  - Sarvan, Darko
AU  - Ajtić, Jelena
PY  - 2019
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/1745
AB  - The activity concentrations of beryllium-7, a natural radiotracer that is considered as a tracer of the strato-spheric-tropospheric exchange, shows a distinct behaviour in Northern Europe compared to the central and southern parts of the continent. In this study, we use the measurements collected at four sampling stations in Scandinavia (Ivalo, Umea, Kista, Risoe) between 2001 and 2010 and investigate their trends, periodicities and residuals with the aim to further understand the common features in the beryllium-7 data records in northern sampling sites. The beryllium-7 activity concentrations exhibit statistically significant positive trends that range from an average value of 1.50%/year to an average value of 2.96%/year. We detect a one-year periodicity in all the sites, and in the southernmost site, Risoe in Denmark, additional higher-frequency harmonics. In the residual time series, we find outliers that represent occurrences of extremely high beryllium-7 activity concentration. Cross-correlations of the beryllium-7 residuals across the four sites decrease with increasing distance; similarly, as indicated by local Hurst exponents the records exhibit long-range correlations that weaken towards the end of the investigated period. To investigate the causes of the detected trends, we also calculate correlations between beryllium-7 and factors related to its production, transport and removal from the atmosphere: in particular, cross-correlations of the beryllium-7 residuals with residuals in sunspot number, local temperature, atmospheric pressure and precipitation, as well as Arctic Oscillation index and North Atlantic Oscillation index. Most of the obtained correlations, however, are not statistically significant, highlighting the need to analyse a longer time period in order to evaluate the impact of different factors on the airborne beryllium-7 activity concentration.
PB  - Pergamon-Elsevier Science Ltd, Oxford
T2  - Applied Radiation and Isotopes
T1  - Analysis of trends, periodicities, and correlations in the beryllium-7 time series in Northern Europe
VL  - 148
SP  - 160
EP  - 167
DO  - 10.1016/j.apradiso.2019.03.038
ER  - 

@article{
author = "Bianchi, Stefano and Plastino, Wolfango and Brattich, Erika and Đurđević, Vladimir and Longo, Alessandro and Hernandez-Ceballos, Miguel A. and Sarvan, Darko and Ajtić, Jelena",
year = "2019",
abstract = "The activity concentrations of beryllium-7, a natural radiotracer that is considered as a tracer of the strato-spheric-tropospheric exchange, shows a distinct behaviour in Northern Europe compared to the central and southern parts of the continent. In this study, we use the measurements collected at four sampling stations in Scandinavia (Ivalo, Umea, Kista, Risoe) between 2001 and 2010 and investigate their trends, periodicities and residuals with the aim to further understand the common features in the beryllium-7 data records in northern sampling sites. The beryllium-7 activity concentrations exhibit statistically significant positive trends that range from an average value of 1.50%/year to an average value of 2.96%/year. We detect a one-year periodicity in all the sites, and in the southernmost site, Risoe in Denmark, additional higher-frequency harmonics. In the residual time series, we find outliers that represent occurrences of extremely high beryllium-7 activity concentration. Cross-correlations of the beryllium-7 residuals across the four sites decrease with increasing distance; similarly, as indicated by local Hurst exponents the records exhibit long-range correlations that weaken towards the end of the investigated period. To investigate the causes of the detected trends, we also calculate correlations between beryllium-7 and factors related to its production, transport and removal from the atmosphere: in particular, cross-correlations of the beryllium-7 residuals with residuals in sunspot number, local temperature, atmospheric pressure and precipitation, as well as Arctic Oscillation index and North Atlantic Oscillation index. Most of the obtained correlations, however, are not statistically significant, highlighting the need to analyse a longer time period in order to evaluate the impact of different factors on the airborne beryllium-7 activity concentration.",
publisher = "Pergamon-Elsevier Science Ltd, Oxford",
journal = "Applied Radiation and Isotopes",
title = "Analysis of trends, periodicities, and correlations in the beryllium-7 time series in Northern Europe",
volume = "148",
pages = "160-167",
doi = "10.1016/j.apradiso.2019.03.038"
}

Bianchi, S., Plastino, W., Brattich, E., Đurđević, V., Longo, A., Hernandez-Ceballos, M. A., Sarvan, D.,& Ajtić, J.. (2019). Analysis of trends, periodicities, and correlations in the beryllium-7 time series in Northern Europe. in Applied Radiation and Isotopes
Pergamon-Elsevier Science Ltd, Oxford., 148, 160-167.
https://doi.org/10.1016/j.apradiso.2019.03.038

Bianchi S, Plastino W, Brattich E, Đurđević V, Longo A, Hernandez-Ceballos MA, Sarvan D, Ajtić J. Analysis of trends, periodicities, and correlations in the beryllium-7 time series in Northern Europe. in Applied Radiation and Isotopes. 2019;148:160-167.
doi:10.1016/j.apradiso.2019.03.038 .

Bianchi, Stefano, Plastino, Wolfango, Brattich, Erika, Đurđević, Vladimir, Longo, Alessandro, Hernandez-Ceballos, Miguel A., Sarvan, Darko, Ajtić, Jelena, "Analysis of trends, periodicities, and correlations in the beryllium-7 time series in Northern Europe" in Applied Radiation and Isotopes, 148 (2019):160-167,
https://doi.org/10.1016/j.apradiso.2019.03.038 . .