Long-term variations in the surface air 7Be concentration and climatic changes

► We used over 25 years of data from 23 sites to analyze 7Be concentration. ► We used non-linear regression method and Seasonal Kendall Test to extract long-term trend of 7Be surface air concentration. ► The surface air 7Be concentrations in most sites show a strong decreasing trend. ► There is a weak negative correlation between the 7Be concentration and the amount of precipitation.