Seasonal variability in 7Be depositional fluxes at Granada, Spain

Measurement of 7Be depositional fluxes at Granada, Spain (37°10′50″N-3°35′44″W, altitude 670 m) in the period 1995 through 1998 indicates substantial variations between the four seasons and also between corresponding seasons in different years, ranging from 23.6 to 242 Bq m−2 per season. A strongly positive correlation with precipitation is shown, which explains about 70% of the variations in the 7Be depositional fluxes over the 16 seasons studied. The depositional 7Be flux is on the average highest in the fall and lowest in the summer. The study shows that precipitation primarily controls the 7Be depositional flux and plays a dominant role in the removal of 7Be from the troposphere. The average annual 7Be depositional flux at Granada amounts to 469+145 Bq m−2.