Analysis of beryllium-7 variability in northern Europe

Abstract

This work presents an overview of the results obtained in an analysis of the 7Be activity concentrations recorded in surface air in Helsinki, Finland, over a 25-year period (1987-2011), and stored in the online Radioactivity Environmental Monitoring (REM) database. First, lagged linear correlations of the 7Be specific activity with several meteorological variables: tropopause height (TPH); mean, minimum and maximum temperature; precipitation (Prec); atmospheric pressure (Press); potential vorticity (PV) at 300 hPa and 200 hPa; solar zenith angle (SZA); and sunspot number are analysed (Tab. 1). The time lag in the correlation calculations is allowed to vary between 0 and 7 days for TPH, meteorological parameters and PV, and between 0 and 31 days for SZA and sunspot number. The correlations are calculated for the total set of measurements as well as for different seasons.