Seasonal variations of atmospheric²¹⁰Pb and⁷Be concentrations at Kumamoto, Japan and their removal from the atmosphere as wet and dry depositions</p> </p>

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.</p> </p>