Distribution of 7Be in surface air of Europe

• This study deals with long-term (span over three decades, 1972-2003) distribution of the cosmogenic isotope Be-7 in surface air at 5 stations in Europe, extending from latitude 47 degrees N to 68 degrees N. The results suggest annual variability in all the data sets as well as a decrease in average Be-7 activity with increasing latitude. Furthermore, a 9-10-year cyclical pattern is observed in the Be-7 distribution, which is anticorrelated with the solar activity cycle. Our data also indicate a dynamic range of Be-7 activity for each solar cycle and phase (maximum or minimum) which is higher at the middle compared to high-latitude regions. Additionally, about 10-20% relative deviation is observed in Be-7 activity during solar maxima and minima compared to the total average Be-7. This feature indicates that some deviation in the worldwide Be-7 activity data may relate to their acquisition, with respect to which part of a solar cycle they have been collected in (time span) and at which latitudinal spread. Estimate of Be-7 flux onto European surface boundary layer vary from 0.4 to 0.9 x 10(10) atoms m(-2) yr(-1) which is strongly latitude dependent and our average value is comparable to the similar to 0.7-0.8 x 10(10) atoms m(-2) yr(-1) across ocean and land.

Subject headings

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

NATURVETENSKAP  -- Geovetenskap och miljövetenskap -- Meteorologi och atmosfärforskning (hsv//swe)

NATURAL SCIENCES  -- Earth and Related Environmental Sciences -- Meteorology and Atmospheric Sciences (hsv//eng)

Keyword

atmosphere; cosmogenic Be-7; Europe; solar activity; Sweden

Publication and Content Type

ref (subject category)

art (subject category)