Understanding the variability of 7Be surface concentrations in Europe: the role of teleconnection patterns

• Main Authors: Hernández Ceballos, Miguel Ángel, Ajtić, Jelena, Brattich, Erika
• Format: Conference Object
• Language: English
• Published: European Meteorological Society 2023
• Subjects: Arctic; North Atlantic; North Atlantic oscillation
• Online Access: https://vet-erinar.vet.bg.ac.rs/handle/123456789/3273; https://doi.org/10.5194/ems2023-204; http://veterinar.vet.bg.ac.rs/bitstream/id/9709/bitstream_9709.pdf

The temporal and spatial variability of atmospheric compounds and pollutants is largely driven by a combination of local, mesoscale and synoptic meteorological conditions influencing atmospheric processes, such as horizontal and vertical dispersion, deposition, chemical reactions rates and velocity. At the same time, different anthropogenic and natural radionuclides have long been used as tracers to understand and describe surface and atmospheric processes and their influence on transport and deposition. Among these substances, 7Be, a cosmogenic radionuclide produced by spallation reactions in the stratosphere and upper troposphere, is frequently used as tracer of different atmospheric processes. Many studies have reported how the variability of 7Be surface concentration is driven by the movement of air masses, atmospheric deposition processes, tropospheric vertical mixing, and the vertical exchange between the stratosphere and the troposphere. With an aim to elucidate the influence of teleconnection and tropospheric circulation dynamics, several studies have investigated the influence of the main modes of large scale and regional climate variability in Europe, such as North Atlantic Oscillation (NAO), Arctic Oscillation (AO), East Atlantic (EA), East Atlantic/Western Russia (EA/WR), Scandinavian pattern (SCAND), and Western Mediterranean Oscillation (WeMO) on the surface 7Be activity concentrations. This paper, in particular, presents a summary of recent results achieved by our team working on this topic, focusing firstly at the European scale and then to northern Europe. Analysing 7Be surface concentrations measured at 15 European sampling stations over 2005–2014 and combining the calculation of air mass trajectories and cluster analysis with time series of teleconnection indices, we found that extremely high values of the 7Be surface concentrations are largely connected with the negative phase of NAO and We-MO, and with the positive EA phase. These results showed a latitudinal division between the northern ...