Solar and meteorological influences on seasonal atmospheric 7Be in Europe for 1975 to 2018. (January 2021)

• Record Type: Journal Article
• Authors: Zheng, Minjie; Sjolte, Jesper; Adolphi, Florian; Aldahan, Ala; Possnert, Göran; Wu, Mousong; Muscheler, Raimund
• Is Part Of: Chemosphere. Volume 263(2021)
• Publication Date: 2021-01
• Subjects: Beryllium-7 -- Solar modulation -- Meteorological influences -- Stepwise regression -- Three-box model -- Stratospheric intrusion; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2020.128318
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: Assessing the transport of natural radionuclides in the atmosphere provides a powerful tool to study air mass circulation. Here, we investigated the seasonal atmospheric distribution of the naturally produced 7 Be in surface air over Europe between 40° N and 68° N during the period 1975–2018. The results suggest that the inter-annual variability of 7 Be reflects production rates of the radionuclide induced by solar modulation of cosmic rays. Further analysis of the meteorological influences indicates that the meteorological influences on 7 Be concentrations are geographically and seasonally dependent. We found that, in general, the tropopause pressure plays an important factor influencing 7 Be activity for winter and spring seasons while the sea level pressure and temperature are more dominant during summer and autumn seasons. The combination of tropospheric production rates and meteorological parameters explains 24%–79% variances of the seasonal 7 Be activity. We further applied a three-box model to study the influence of stratosphere-troposphere exchanges on 7 Be concentrations. The simulation supports that the seasonal cycle of 7 Be in Europe is controlled by two main factors: the changing height of the troposphere (seasonality of the tropopause height) and seasonal variations of the stratosphere-troposphere exchanges. Highlights: We investigated the main drivers of the inter-annual variability of 7 Be in Europe. A method is proposed to separate solar and meteorological impacts on air 7 Be. Meteorological influences on air 7 Be are geographically and seasonally dependent. The box simulation supports the impact of stratospheric intrusion on air 7 Be.