TY  - CONF
AU  - Stratimirović, Đorđe
AU  - Hernández-Ceballos, Miguel Ángel
AU  - Brattich, Erika
AU  - Sarvan, Darko
AU  - Ajtić, Jelena
PY  - 2022
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/2477
AB  - The natural radionuclide beryllium-7 (Be-7) is produced in the upper levels of the atmosphere and is transported to the surface on carrier aerosols. Therefore, among other factors, the abundance of Be-7 in the surface air is governed by the rate of its production and large-scale air transport. The North Atlantic Oscillation (NAO) index, which quantifies the surface sea-level pressure difference between the Subtropical (Azores) High and Subpolar low, exerts large effects on precipitation and circulation patterns in Europe. With an aim to look closely into the interrelations between the Be-7 specific activity in the surface air, sunspot number (as a proxy for the production signal), and NAO index, this paper investigates their long-term time series over 28 years, between February 1987 and December 2014.
The Be-7 specific activity was recorded in Vienna (48.22 ºN; 16.35 ºE; 193 m a.s.l.), Austria, and stored in the Radioactivity Environmental Monitoring databank (REMdb) that is created and supported by the European Commission-Joint Research Centre in Ispra, Italy. The sunspot number (SN) data were downloaded from SILSO (Royal Observatory of Belgium, Brussels, Belgium), while the NAO records were retrieved from the Climate Prediction Centre of the National Oceanic and Atmospheric Administration, USA. Since the temporal resolution of the Be-7 measurements varied between six and eight days, they were first linearly interpolated into an array of weekly data, and then, the daily SN and NAO data were averaged into weekly records to match the Be-7 data. Next, Pearson’s correlation analysis and wavelet transform were used to analyse the time series.
The low Pearson’s correlation coefficients between the Be-7 specific activity in the surface air and SN (-0.15207) on one hand, and the NAO index and SN (0.13512) on the other hand, imply a lack of direct linear interrelations between these variables. The Pearson’s correlation coefficient between the Be-7 specific activity in the surface air and NAO index is even lower (-0.05904). However, the Be-7 specific activity wavelet spectrum shows a pronounced annual period, and looking further into the link between the Be-7 specific activity and NAO index at this characteristic periodicity, reveals a prominent pattern. Specifically, the wavelet coherence levels between these two parameters show variations that seem to be in agreement with the 11-year solar cycle: the coherence increases as the sunspot number transitions between its extremes, and it decreases around the maxima and minima in sunspot number. Further, phase difference shows that at the one-year periodicity, the Be-7 specific activity always lags behind the NAO index. The phase difference ranges between 2 and 6 months; it reaches the minimum around the solar activity extremes, and the maximum in-between.
These findings imply that, although weak, the signature of sunspot number can be seen in the wavelet coherence level between the Be-7 specific activity and NAO index.
PB  - RAD Association
C3  - RAD Conference Proceedings
T1  - Interrelation between the beryllium-7 specific activity in the surface air and North Atlantic Oscillation based on their wavelet coherence
SP  - 110
DO  - 10.21175/rad.sum.abstr.book.2022.27.2
ER  - 

@conference{
author = "Stratimirović, Đorđe and Hernández-Ceballos, Miguel Ángel and Brattich, Erika and Sarvan, Darko and Ajtić, Jelena",
year = "2022",
abstract = "The natural radionuclide beryllium-7 (Be-7) is produced in the upper levels of the atmosphere and is transported to the surface on carrier aerosols. Therefore, among other factors, the abundance of Be-7 in the surface air is governed by the rate of its production and large-scale air transport. The North Atlantic Oscillation (NAO) index, which quantifies the surface sea-level pressure difference between the Subtropical (Azores) High and Subpolar low, exerts large effects on precipitation and circulation patterns in Europe. With an aim to look closely into the interrelations between the Be-7 specific activity in the surface air, sunspot number (as a proxy for the production signal), and NAO index, this paper investigates their long-term time series over 28 years, between February 1987 and December 2014.
The Be-7 specific activity was recorded in Vienna (48.22 ºN; 16.35 ºE; 193 m a.s.l.), Austria, and stored in the Radioactivity Environmental Monitoring databank (REMdb) that is created and supported by the European Commission-Joint Research Centre in Ispra, Italy. The sunspot number (SN) data were downloaded from SILSO (Royal Observatory of Belgium, Brussels, Belgium), while the NAO records were retrieved from the Climate Prediction Centre of the National Oceanic and Atmospheric Administration, USA. Since the temporal resolution of the Be-7 measurements varied between six and eight days, they were first linearly interpolated into an array of weekly data, and then, the daily SN and NAO data were averaged into weekly records to match the Be-7 data. Next, Pearson’s correlation analysis and wavelet transform were used to analyse the time series.
The low Pearson’s correlation coefficients between the Be-7 specific activity in the surface air and SN (-0.15207) on one hand, and the NAO index and SN (0.13512) on the other hand, imply a lack of direct linear interrelations between these variables. The Pearson’s correlation coefficient between the Be-7 specific activity in the surface air and NAO index is even lower (-0.05904). However, the Be-7 specific activity wavelet spectrum shows a pronounced annual period, and looking further into the link between the Be-7 specific activity and NAO index at this characteristic periodicity, reveals a prominent pattern. Specifically, the wavelet coherence levels between these two parameters show variations that seem to be in agreement with the 11-year solar cycle: the coherence increases as the sunspot number transitions between its extremes, and it decreases around the maxima and minima in sunspot number. Further, phase difference shows that at the one-year periodicity, the Be-7 specific activity always lags behind the NAO index. The phase difference ranges between 2 and 6 months; it reaches the minimum around the solar activity extremes, and the maximum in-between.
These findings imply that, although weak, the signature of sunspot number can be seen in the wavelet coherence level between the Be-7 specific activity and NAO index.",
publisher = "RAD Association",
journal = "RAD Conference Proceedings",
title = "Interrelation between the beryllium-7 specific activity in the surface air and North Atlantic Oscillation based on their wavelet coherence",
pages = "110",
doi = "10.21175/rad.sum.abstr.book.2022.27.2"
}

Stratimirović, Đ., Hernández-Ceballos, M. Á., Brattich, E., Sarvan, D.,& Ajtić, J.. (2022). Interrelation between the beryllium-7 specific activity in the surface air and North Atlantic Oscillation based on their wavelet coherence. in RAD Conference Proceedings
RAD Association., 110.
https://doi.org/10.21175/rad.sum.abstr.book.2022.27.2

Stratimirović Đ, Hernández-Ceballos MÁ, Brattich E, Sarvan D, Ajtić J. Interrelation between the beryllium-7 specific activity in the surface air and North Atlantic Oscillation based on their wavelet coherence. in RAD Conference Proceedings. 2022;:110.
doi:10.21175/rad.sum.abstr.book.2022.27.2 .

Stratimirović, Đorđe, Hernández-Ceballos, Miguel Ángel, Brattich, Erika, Sarvan, Darko, Ajtić, Jelena, "Interrelation between the beryllium-7 specific activity in the surface air and North Atlantic Oscillation based on their wavelet coherence" in RAD Conference Proceedings (2022):110,
https://doi.org/10.21175/rad.sum.abstr.book.2022.27.2 . .

TY  - JOUR
AU  - Brattich, Erika
AU  - Liu, Hongyu
AU  - Zhang, Bo
AU  - Hernández-Ceballos, Miguel Ángel
AU  - Paatero, Jussi
AU  - Sarvan, Darko
AU  - Djurdjević, Vladimir
AU  - Tositti, Laura
AU  - Ajtić, Jelena
PY  - 2021
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/2336
AB  - Abstract. Events of very high concentrations of 7Be cosmogenic radionuclide have been recorded at low-elevation surface stations in the subpolar regions of Europe during the cold season. With an aim to investigate the mechanisms responsible for those peak 7Be events, and in particular to verify if they are associated with the fast descent of stratospheric air masses occurring during sudden stratospheric warming (SSW) events, we analyze 7Be observations at six sampling sites in Fennoscandia during January–March 2003 when very high 7Be concentrations were observed and the Arctic vortex was relatively unstable as a consequence of several SSW events. We use the GEOS-Chem chemistry and transport model driven by the MERRA-2 meteorological reanalysis to simulate tropospheric 7Be over northern Europe. We show that the model reasonably reproduces the temporal evolution of surface 7Be concentrations observed at the six sampling sites. Our analysis of model simulations, surface 7Be observations, atmospheric soundings of ozone and temperature and surface ozone measurements indicates that the 7Be peak observed in late February 2003 (between 20 and 28 February 2003) at the six sampling sites in Fennoscandia was associated with downward transport of stratospheric vortex air that originated during an SSW that occurred a few days earlier (between 18 and 21 February 2003).
T2  - Atmospheric Chemistry and Physics
T1  - Observation and modeling of high-7Be concentration events at the surface in northern Europe associated with the instability of the Arctic polar vortex in early 2003
VL  - 21
IS  - 23
SP  - 17927
EP  - 17951
DO  - 10.5194/acp-21-17927-2021
ER  - 

@article{
author = "Brattich, Erika and Liu, Hongyu and Zhang, Bo and Hernández-Ceballos, Miguel Ángel and Paatero, Jussi and Sarvan, Darko and Djurdjević, Vladimir and Tositti, Laura and Ajtić, Jelena",
year = "2021",
abstract = "Abstract. Events of very high concentrations of 7Be cosmogenic radionuclide have been recorded at low-elevation surface stations in the subpolar regions of Europe during the cold season. With an aim to investigate the mechanisms responsible for those peak 7Be events, and in particular to verify if they are associated with the fast descent of stratospheric air masses occurring during sudden stratospheric warming (SSW) events, we analyze 7Be observations at six sampling sites in Fennoscandia during January–March 2003 when very high 7Be concentrations were observed and the Arctic vortex was relatively unstable as a consequence of several SSW events. We use the GEOS-Chem chemistry and transport model driven by the MERRA-2 meteorological reanalysis to simulate tropospheric 7Be over northern Europe. We show that the model reasonably reproduces the temporal evolution of surface 7Be concentrations observed at the six sampling sites. Our analysis of model simulations, surface 7Be observations, atmospheric soundings of ozone and temperature and surface ozone measurements indicates that the 7Be peak observed in late February 2003 (between 20 and 28 February 2003) at the six sampling sites in Fennoscandia was associated with downward transport of stratospheric vortex air that originated during an SSW that occurred a few days earlier (between 18 and 21 February 2003).",
journal = "Atmospheric Chemistry and Physics",
title = "Observation and modeling of high-7Be concentration events at the surface in northern Europe associated with the instability of the Arctic polar vortex in early 2003",
volume = "21",
number = "23",
pages = "17927-17951",
doi = "10.5194/acp-21-17927-2021"
}

Brattich, E., Liu, H., Zhang, B., Hernández-Ceballos, M. Á., Paatero, J., Sarvan, D., Djurdjević, V., Tositti, L.,& Ajtić, J.. (2021). Observation and modeling of high-7Be concentration events at the surface in northern Europe associated with the instability of the Arctic polar vortex in early 2003. in Atmospheric Chemistry and Physics, 21(23), 17927-17951.
https://doi.org/10.5194/acp-21-17927-2021

Brattich E, Liu H, Zhang B, Hernández-Ceballos MÁ, Paatero J, Sarvan D, Djurdjević V, Tositti L, Ajtić J. Observation and modeling of high-7Be concentration events at the surface in northern Europe associated with the instability of the Arctic polar vortex in early 2003. in Atmospheric Chemistry and Physics. 2021;21(23):17927-17951.
doi:10.5194/acp-21-17927-2021 .

Brattich, Erika, Liu, Hongyu, Zhang, Bo, Hernández-Ceballos, Miguel Ángel, Paatero, Jussi, Sarvan, Darko, Djurdjević, Vladimir, Tositti, Laura, Ajtić, Jelena, "Observation and modeling of high-7Be concentration events at the surface in northern Europe associated with the instability of the Arctic polar vortex in early 2003" in Atmospheric Chemistry and Physics, 21, no. 23 (2021):17927-17951,
https://doi.org/10.5194/acp-21-17927-2021 . .

TY  - DATA
AU  - Brattich, Erika
AU  - Liu, Hongyu
AU  - Zhang, Bo
AU  - Hernández-Ceballos, Miguel Ángel
AU  - Paatero, Jussi
AU  - Sarvan, Darko
AU  - Djurdjević, Vladimir
AU  - Tositti, Laura
AU  - Ajtić, Jelena
PY  - 2021
UR  - https://vet-erinar.vet.bg.ac.rs/handle/123456789/2337
T2  - Atmospheric Chemistry and Physics
T1  - Supplementary data for article:  Brattich, E.; Liu, H.; Zhang, B.; Hernández-Ceballos, M. Á.; Paatero, J.; Sarvan, D.; Djurdjevic, V.; Tositti, L.; Ajtić, J. Observation and Modeling of High-7Be Concentration Events at the Surface in Northern Europe Associated with the Instability of the Arctic Polar Vortex in Early 2003. Atmospheric Chemistry and Physics 2021, 21 (23), 17927–17951. https://doi.org/10.5194/acp-21-17927-2021
VL  - 21
IS  - 23
SP  - 17927
EP  - 17951
DO  - 10.5194/acp-21-17927-2021-supplement
ER  - 

@misc{
author = "Brattich, Erika and Liu, Hongyu and Zhang, Bo and Hernández-Ceballos, Miguel Ángel and Paatero, Jussi and Sarvan, Darko and Djurdjević, Vladimir and Tositti, Laura and Ajtić, Jelena",
year = "2021",
journal = "Atmospheric Chemistry and Physics",
title = "Supplementary data for article:  Brattich, E.; Liu, H.; Zhang, B.; Hernández-Ceballos, M. Á.; Paatero, J.; Sarvan, D.; Djurdjevic, V.; Tositti, L.; Ajtić, J. Observation and Modeling of High-7Be Concentration Events at the Surface in Northern Europe Associated with the Instability of the Arctic Polar Vortex in Early 2003. Atmospheric Chemistry and Physics 2021, 21 (23), 17927–17951. https://doi.org/10.5194/acp-21-17927-2021",
volume = "21",
number = "23",
pages = "17927-17951",
doi = "10.5194/acp-21-17927-2021-supplement"
}

Brattich, E., Liu, H., Zhang, B., Hernández-Ceballos, M. Á., Paatero, J., Sarvan, D., Djurdjević, V., Tositti, L.,& Ajtić, J.. (2021). Supplementary data for article:  Brattich, E.; Liu, H.; Zhang, B.; Hernández-Ceballos, M. Á.; Paatero, J.; Sarvan, D.; Djurdjevic, V.; Tositti, L.; Ajtić, J. Observation and Modeling of High-7Be Concentration Events at the Surface in Northern Europe Associated with the Instability of the Arctic Polar Vortex in Early 2003. Atmospheric Chemistry and Physics 2021, 21 (23), 17927–17951. https://doi.org/10.5194/acp-21-17927-2021. in Atmospheric Chemistry and Physics, 21(23), 17927-17951.
https://doi.org/10.5194/acp-21-17927-2021-supplement

Brattich E, Liu H, Zhang B, Hernández-Ceballos MÁ, Paatero J, Sarvan D, Djurdjević V, Tositti L, Ajtić J. Supplementary data for article:  Brattich, E.; Liu, H.; Zhang, B.; Hernández-Ceballos, M. Á.; Paatero, J.; Sarvan, D.; Djurdjevic, V.; Tositti, L.; Ajtić, J. Observation and Modeling of High-7Be Concentration Events at the Surface in Northern Europe Associated with the Instability of the Arctic Polar Vortex in Early 2003. Atmospheric Chemistry and Physics 2021, 21 (23), 17927–17951. https://doi.org/10.5194/acp-21-17927-2021. in Atmospheric Chemistry and Physics. 2021;21(23):17927-17951.
doi:10.5194/acp-21-17927-2021-supplement .

Brattich, Erika, Liu, Hongyu, Zhang, Bo, Hernández-Ceballos, Miguel Ángel, Paatero, Jussi, Sarvan, Darko, Djurdjević, Vladimir, Tositti, Laura, Ajtić, Jelena, "Supplementary data for article:  Brattich, E.; Liu, H.; Zhang, B.; Hernández-Ceballos, M. Á.; Paatero, J.; Sarvan, D.; Djurdjevic, V.; Tositti, L.; Ajtić, J. Observation and Modeling of High-7Be Concentration Events at the Surface in Northern Europe Associated with the Instability of the Arctic Polar Vortex in Early 2003. Atmospheric Chemistry and Physics 2021, 21 (23), 17927–17951. https://doi.org/10.5194/acp-21-17927-2021" in Atmospheric Chemistry and Physics, 21, no. 23 (2021):17927-17951,
https://doi.org/10.5194/acp-21-17927-2021-supplement . .