Seasonal variations of atmospheric²¹⁰Pb and⁷Be concentrations at Kumamoto, Japan and theirremoval from the atmosphere as wet and dry depositions

Summary  Atmospheric concentrations, dry and total depositions of7Be and210Pb were analyzed at Kumamoto, Japan from December 2001 to November 2003. Meteorologically derived change of air masses in Kumamoto resulted in lower atmospheric concentrations in summer than other seasons. The deposition of7Be and210Pb was large in winter and spring, however, the values of precipitation-normalized deposition indicated a clearer peak in winter than in spring, though the stratosphere-troposphere exchange supplies7Be at mid latitude in spring. The deposition velocity suggested that the wet deposition process functioned almost equally for both nuclides but the dry deposition process was much effective for210Pb.